Method for cooling atomic objects confined by atomic object confinement means

Abstract

An atomic object confined in a particular region of an atomic object confinement device is cooled using an EIT cooling operation from S to P to D. A controller associated with the atomic object confinement device controls a first steering source and a second steering source to provide a first steering signal and a second steering signal, respectively, to the particular region. The first steering signal is characterized by a first wavelength corresponding to a transition between an S manifold and a P manifold of a first component of the atomic object, and the S to P transition is detuned by a first detuning amount. The second steering signal is characterized by a second wavelength corresponding to a transition between the P manifold and a D manifold of the first component, and the P to D transition is detuned by a second detuning amount. The first detuning amount and the second detuning amount are selected to establish a dark state associated with a two-photon transition between the S manifold and the D manifold.

Description

Technical Field

[0001] Various embodiments relate to laser cooling of atomic objects confined by atomic object confinement devices. For example, various embodiments relate to sympathetic EIT cooling using S-to-P-to-D conversion. For example, various embodiments relate to sympathetic EIT cooling using atomic object clock states.

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Application No. 63 / 228,486, filed August 2, 2021, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0004] In various situations, it is desirable to cool ions trapped by an ion trap so that various operations can be performed on the ions (e.g., experiments, controlled quantum evolution, etc.). However, conventional laser cooling techniques tend to be complex and / or require high-power laser beams. Through effort, ingenuity, and innovation, many shortcomings of such conventional laser cooling systems have been addressed by developing solutions constructed according to embodiments of the present invention, many examples of which are described in detail herein. Summary of the Invention

[0005] Example embodiments provide quantum computers, systems, devices, etc., and corresponding methods for performing EIT cooling based on one or more states of the S-manifold of a first component of an atomic object, via two-photon resonant transitions between one or more states of the P-manifold of the first component of the atomic object and the D-manifold of the first component of the atomic object. Example embodiments also provide quantum computers, systems, devices, etc., and corresponding methods for performing EIT cooling based on the clock state of the first component of an atomic object. In various embodiments, the atomic object is an atomic crystal, a group of atoms (neutral and / or ionized), or a group of molecules (neutral and / or ionized), and the component of the atomic object (e.g., the first component) is at least one atom or molecule of a specific type of the atomic object (e.g., element type, chemical formula, etc.). For example, in one example embodiment, the atomic object includes a cooling ion of a first element type and a qubit ion of a second element type, wherein the cooling ion is referred to herein as the first component of the example atomic object. For example, in one example embodiment, the first component of the atomic object is cooled by EIT cooling, and the second component of the atomic object is cooled by co-cooling through interaction with the first component of the atomic object. In one example embodiment, the second component is used as a qubit of a quantum computer.

[0006] According to one aspect, a method for cooling an atomic object confined by an atomic object confining device is provided. In an example embodiment, the method includes controlling a first manipulation source via a controller associated with the atomic object confining device to provide a first manipulation signal to a specific region of the atomic object confining device. The method also includes controlling a second manipulation source via the controller to provide a second manipulation signal to a specific region of the atomic object confining device. The atomic object to be cooled is located in the specific region of the atomic object confining device. The first manipulation signal is characterized by a first wavelength corresponding to a transition between an S-manifold and a P-manifold of a first component of the atomic object, and detuning from the transition between the S-manifold and the P-manifold by a first detuning amount. The second manipulation signal is characterized by a second wavelength corresponding to a transition between a P-manifold and a D-manifold of the first component of the atomic object, and detuning from the transition between the P-manifold and the D-manifold by a second detuning amount. The first detuning amount and the second detuning amount are selected to establish a dark state associated with a two-photon transition between the S-manifold and the D-manifold.

[0007] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0008] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0009] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0010] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal. In one example embodiment, the first manipulation signal is a π-polarized laser beam, and the second manipulation signal is a σ-polarized laser beam.

[0011] In one example embodiment, the polarization of the first manipulation signal and the polarization of the second manipulation signal correspond to a two-photon transition associated with the dark state.

[0012] In one example embodiment, the method further includes generating a magnetic field with a magnetic field direction in a specific region of the atomic object limiting device, wherein an atomic object or a specific region of the atomic object limiting device defines an atomic object axis, and the magnetic field direction is transverse to the atomic object axis.

[0013] In one example embodiment, the direction of the magnetic field forms an angle of thirty to sixty degrees with the axis of the atomic object.

[0014] In one example embodiment, a first manipulation signal defines a first propagation direction transverse to the axis of the atom object, and a second manipulation signal defines a second propagation direction transverse to the axis of the atom object.

[0015] In one example embodiment, the first propagation direction and the second propagation direction are approximately antiparallel to each other, and the magnetic field direction is transverse to both the first propagation direction and the second propagation direction.

[0016] In one example embodiment, both the first propagation direction and the second propagation direction are approximately perpendicular to the direction of the magnetic field.

[0017] In one example embodiment, (a) the polarization of the first manipulation signal is generally transverse to the plane defined by the atomic object limiting device, (b) the polarization of the second manipulation signal is generally transverse to the plane defined by the atomic object limiting device, and (c) the first propagation direction, the second propagation direction, and the magnetic field direction are generally parallel to the plane defined by the atomic limiting device.

[0018] According to another aspect, an apparatus configured to induce and / or control cooling of an atomic object confined by an atomic object confining device is provided. In one example embodiment, the apparatus includes at least one processor and a memory storing computer-executable instructions. The computer-executable instructions are configured, when executed by the at least one processor, to cause the apparatus to at least control a first manipulation source to provide a first manipulation signal to a specific region of the atomic object confining device; and to control a second manipulation source to provide a second manipulation signal to the specific region of the atomic object confining device. The atomic object to be cooled is located within the specific region of the atomic object confining device. The first manipulation signal and the second manipulation signal are configured to co-cool the atomic object. The first manipulation signal is characterized by a first wavelength corresponding to a transition between an S-manifold and a P-manifold of a first component of the atomic object, and a first detuning amount from the transition between the S-manifold and the P-manifold. The second manipulation signal is characterized by a second wavelength corresponding to a transition between a P-manifold and a D-manifold of the first component of the atomic object, and a second detuning amount from the transition between the P-manifold and the D-manifold. The first and second detuning amounts are selected to establish a dark state associated with a two-photon transition between the S-manifold and the D-manifold.

[0019] In one example embodiment, the device is a controller for a quantum computer that includes an atom object confinement device.

[0020] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0021] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0022] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0023] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal. In one example embodiment, the first manipulation signal is a π-polarized laser beam and the second manipulation signal is a σ-polarized laser beam.

[0024] In one example embodiment, the polarization of the first manipulation signal and the polarization of the second manipulation signal correspond to a two-photon transition associated with the dark state.

[0025] In one example embodiment, the computer-executable instructions are further configured to, when executed by at least one processor, cause the means to at least cause the generation of a magnetic field having a magnetic field direction in a specific region of the atomic object limiting means, wherein an atomic object or a specific region of the atomic object limiting means defines an atomic object axis, and the magnetic field direction is transverse to the atomic object axis.

[0026] In one example embodiment, the direction of the magnetic field forms an angle of thirty to sixty degrees with the axis of the atomic object.

[0027] In one example embodiment, a first manipulation signal defines a first propagation direction transverse to the axis of the atom object, and a second manipulation signal defines a second propagation direction transverse to the axis of the atom object.

[0028] In one example embodiment, the first propagation direction and the second propagation direction are approximately antiparallel to each other, and the magnetic field direction is transverse to both the first propagation direction and the second propagation direction.

[0029] In one example embodiment, both the first propagation direction and the second propagation direction are approximately perpendicular to the direction of the magnetic field.

[0030] In one example embodiment, (a) the polarization of the first manipulation signal is generally transverse to the plane defined by the atomic object limiting device, (b) the polarization of the second manipulation signal is generally transverse to the plane defined by the atomic object limiting device, and (c) the first propagation direction, the second propagation direction, and the magnetic field direction are generally parallel to the plane defined by the atomic limiting device.

[0031] According to another aspect, a system is provided. In one example embodiment, the system includes: an atomic object confinement device configured to confine an atomic object within a specific region of the atomic object confinement device; a first manipulation source controllable by a controller of the system and configured to provide a first manipulation signal to the specific region of the atomic object confinement device; a second manipulation source controllable by the controller of the system and providing a second manipulation signal to the specific region of the atomic object confinement device; and a controller. The controller includes at least one processor and a memory storing computer-executable instructions configured, when executed by the at least one processor, to cause the controller to at least control the first manipulation source to provide the first manipulation signal to the specific region of the atomic object confinement device; and to control the second manipulation source to provide the second manipulation signal to the specific region of the atomic object confinement device. The first manipulation signal and the second manipulation signal are configured to co-cool the atomic object. The first manipulation signal is characterized by a first wavelength corresponding to a transition between an S-manifold and a P-manifold of a first component of the atomic object, and a first detuning amount from the transition between the S-manifold and the P-manifold. The second manipulation signal is characterized by a second wavelength corresponding to the transition between the P-manifold and the D-manifold of the first component of the atomic object, and a second detuning amount from the transition between the P-manifold and the D-manifold. The first and second detuning amounts are selected to establish a dark state associated with the two-photon transition between the S-manifold and the D-manifold.

[0032] In one example embodiment, the system is a quantum computer based on a quantum charge-coupled device (QCCD).

[0033] In one example embodiment, the device is a controller for a quantum computer that includes an atom object confinement device.

[0034] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0035] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0036] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0037] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal.

[0038] In one example embodiment, the first manipulation signal is a π-polarized laser beam and the second manipulation signal is a σ-polarized laser beam.

[0039] In one example embodiment, the polarization of the first manipulation signal and the polarization of the second manipulation signal correspond to a two-photon transition associated with the dark state.

[0040] In one example embodiment, the computer-executable instructions are further configured to, when executed by at least one processor, cause the means to at least cause the generation of a magnetic field having a magnetic field direction in a specific region of the atomic object limiting means, wherein an atomic object or a specific region of the atomic object limiting means defines an atomic object axis, and the magnetic field direction is transverse to the atomic object axis.

[0041] In one example embodiment, the direction of the magnetic field forms an angle of thirty to sixty degrees with the axis of the atomic object.

[0042] In one example embodiment, a first manipulation signal defines a first propagation direction transverse to the axis of the atom object, and a second manipulation signal defines a second propagation direction transverse to the axis of the atom object.

[0043] In one example embodiment, the first propagation direction and the second propagation direction are approximately antiparallel to each other, and the magnetic field direction is transverse to both the first propagation direction and the second propagation direction.

[0044] In one example embodiment, both the first propagation direction and the second propagation direction are approximately perpendicular to the direction of the magnetic field.

[0045] In one example embodiment, (a) the polarization of the first manipulation signal is generally transverse to the plane defined by the atomic object limiting device, (b) the polarization of the second manipulation signal is generally transverse to the plane defined by the atomic object limiting device, and (c) the first propagation direction, the second propagation direction, and the magnetic field direction are generally parallel to the plane defined by the atomic limiting device.

[0046] According to another aspect, a method for cooling an atomic object confined by an atomic object confining device is provided. In one example embodiment, the method includes controlling a first manipulation source via a controller associated with the atomic object confining device to provide a first manipulation signal to a specific region of the atomic object confining device. The method also includes controlling a second manipulation source via the controller to provide a second manipulation signal to a specific region of the atomic object confining device. The atomic object to be cooled is located within the specific region of the atomic object confining device. The first manipulation signal is characterized by a first wavelength corresponding to a first transition between a first clock state of an S-manifold and a P-manifold of a first component of the atomic object, and detuning from the first transition by a first detuning amount. The second manipulation signal is characterized by a second wavelength corresponding to a second transition between a second clock state of an S-manifold and a P-manifold of the first component of the atomic object, and detuning from the second transition by a second detuning amount. The first and second detuning amounts are selected to establish a dark state associated with a two-photon transition between the first and second clock states.

[0047] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0048] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0049] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0050] In one example embodiment, the first atom object type is individually ionized ytterbium.

[0051] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal.

[0052] In one example embodiment, the method further includes inducing or controlling the generation of a magnetic field with a magnetic field direction in a specific region of the atomic object confinement device, and the magnetic field direction being transverse to the propagation direction of the first manipulation signal.

[0053] In one example embodiment, the first manipulation signal is characterized by a first polarization, which is a linear polarization that is generally parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization that is generally perpendicular to the plane defined by the atomic object.

[0054] In one example embodiment, the method further includes generating a magnetic field with a magnetic field direction in a specific region of the atomic object confinement device, wherein the magnetic field direction is transverse to the first polarization.

[0055] In one example embodiment, a first manipulation signal is characterized by a first polarization, and a second manipulation signal is characterized by a second polarization, the first polarization being transverse to the second polarization.

[0056] In one example embodiment, the first clock state is F=1, m=0, and the second clock state is F=0, m=0.

[0057] According to another aspect, there is provided an apparatus configured to cause / or control the cooling of an atomic object confined by an atomic object confining device. In one example embodiment, the apparatus includes at least one processor and a memory storing computer-executable instructions. The computer-executable instructions are configured, when executed by the at least one processor, to cause the apparatus to control at least a first manipulation source to provide a first manipulation signal to a specific region of the atomic object confining device; and to control a second manipulation source to provide a second manipulation signal to the specific region of the atomic object confining device. The atomic object to be cooled is located within the specific region of the atomic object confining device. The first manipulation signal and the second manipulation signal are configured to co-cool the atomic object. The first manipulation signal is characterized by a first wavelength corresponding to a first transition between a first clock state of an S-manifold and a P-manifold of a first component of the atomic object, and detunes from the first transition by a first detuning amount. The second manipulation signal is characterized by a second wavelength corresponding to a second transition between a second clock state of an S-manifold and a P-manifold of the first component of the atomic object, and detunes from the second transition by a second detuning amount. The first detuning amount and the second detuning amount are selected to establish a dark state associated with a two-photon transition between the first clock state and the second clock state.

[0058] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0059] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0060] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0061] In one example embodiment, the first atom object type is individually ionized ytterbium.

[0062] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal.

[0063] In one example embodiment, a magnetic field with a magnetic field direction exists in a specific region of the atomic object confinement device, and the magnetic field direction is transverse to the propagation direction of the first manipulation signal.

[0064] In one example embodiment, the first manipulation signal is characterized by a first polarization, which is a linear polarization that is generally parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization that is generally perpendicular to the plane defined by the atomic object.

[0065] In one example embodiment, a magnetic field with a magnetic field direction exists in a specific region of the atomic object confinement device, and the magnetic field direction is transverse to the first polarization.

[0066] In one example embodiment, a first manipulation signal is characterized by a first polarization, and a second manipulation signal is characterized by a second polarization, the first polarization being transverse to the second polarization.

[0067] In one example embodiment, the first clock state is F=1, m=0, and the second clock state is F=0, m=0.

[0068] In one example embodiment, the device is a controller for a quantum computer based on a quantum charge-coupled device (QCCD).

[0069] According to yet another aspect, a system is provided. In one example embodiment, the system includes: an atomic object confinement device configured to confine an atomic object within a specific region of the atomic object confinement device; a first manipulation source controllable by a controller of the system and configured to provide a first manipulation signal to the specific region of the atomic object confinement device; a second manipulation source controllable by the controller of the system and configured to provide a second manipulation signal to the specific region of the atomic object confinement device; and a controller including at least one processor and a memory storing computer-executable instructions. The computer-executable instructions are configured, when executed by the at least one processor, to cause the controller to at least control the first manipulation source to provide the first manipulation signal to the specific region of the atomic object confinement device; and to control the second manipulation source to provide the second manipulation signal to the specific region of the atomic object confinement device. The first manipulation signal and the second manipulation signal are configured to co-cool the atomic object. The first manipulation signal is characterized by a first wavelength corresponding to a first transition between a first clock state of an S-manifold and a P-manifold of a first component of the atomic object, and detunes from the first transition by a first detuning amount. The second manipulation signal is characterized by a second wavelength corresponding to a second transition between the second clock state of the S-manifold and the P-manifold of the first component of the atomic object, and a second detuning amount from the second transition. A first detuning amount and a second detuning amount are selected to establish a dark state associated with the two-photon transition between the first clock state and the second clock state.

[0070] In one example embodiment, the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0071] In one example embodiment, the first component of the atomic object is configured as coolant ions in a synergistic cooling scheme for the crystal.

[0072] In one example embodiment, the second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including an atomic object confinement device.

[0073] In one example embodiment, the first atom object type is individually ionized ytterbium.

[0074] In one example embodiment, the first detuning amount and the second detuning amount are approximately equal.

[0075] In one example embodiment, a magnetic field with a magnetic field direction exists in a specific region of the atomic object confinement device, and the magnetic field direction is transverse to the propagation direction of the first manipulation signal.

[0076] In one example embodiment, the first manipulation signal is characterized by a first polarization, which is a linear polarization that is generally parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization that is generally perpendicular to the plane defined by the atomic object.

[0077] In one example embodiment, a magnetic field with a magnetic field direction exists in a specific region of the atomic object confinement device, and the magnetic field direction is transverse to the first polarization.

[0078] In one example embodiment, a first manipulation signal is characterized by a first polarization, and a second manipulation signal is characterized by a second polarization, the first polarization being transverse to the second polarization.

[0079] In one example embodiment, the first clock state is F=1, m=0, and the second clock state is F=0, m=0.

[0080] In one example embodiment, the system is a quantum computer based on a quantum charge-coupled device (QCCD). Attached Figure Description

[0081] The invention has been described in such general terms that reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0082] Figure 1 A block diagram of an example atom-object quantum computer according to an example embodiment is provided.

[0083] Figure 2A An energy level diagram of the first component of an atomic object is provided, illustrating the performance of a cooling operation according to an example embodiment.

[0084] Figure 2B An energy level diagram of a first component of an atomic object is provided, illustrating the performance of a cooling operation according to another example embodiment.

[0085] Figure 3A Provided is an example embodiment, corresponding to Figure 2A The diagram shown illustrates the execution of the cooling operation of the energy level diagram.

[0086] Figure 3B Provided is an example embodiment, corresponding to Figure 2B This is a schematic diagram illustrating the execution of another cooling operation in the energy level diagram shown.

[0087] Figure 4 An energy level diagram of a first component of an atomic object is provided, illustrating the performance of a cooling operation according to another example embodiment.

[0088] Figure 5 Provided is an example embodiment, corresponding to Figure 4 The diagram shown illustrates the execution of the cooling operation of the energy level diagram.

[0089] Figure 6 Flowcharts are provided illustrating various processes and / or procedures for cooling operations according to an example embodiment.

[0090] Figure 7 A schematic diagram of an example controller for a quantum computer, according to an example embodiment, is provided, including an atomic object confinement device configured to confine atomic objects therein.

[0091] Figure 8 A schematic diagram of an example computational entity of a quantum computer system that can be used according to an example embodiment is provided. Detailed Implementation

[0092] The invention will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments of the invention. In fact, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable this disclosure to meet applicable legal requirements. Unless otherwise stated, the term “or” (also denoted as “ / ”) is used herein in a meaning of substitution and combination. The terms “illustrative” and “exemplary” are used as examples only and do not indicate a level of quality. Unless otherwise stated, the terms “general” and “about” mean within applicable engineering and / or manufacturing tolerances and / or within the user’s measurement capabilities. The same numbers always refer to the same elements.

[0093] In various scenarios, atomic objects are confined within atomic object confinement devices. In various embodiments, the atomic object confinement device is an ion trap, such as a surface ion trap, a Paul ion trap, and / or the like. In various embodiments, the atomic object is an ion, an atom, an ionic crystal, an atomic crystal, etc. In one example embodiment, the atomic object comprises two or more ions, wherein a first component of the atomic object is one or more ions of a first atomic type (e.g., a first chemical element, an ion of a first atomic number, etc.). In one example embodiment, the atomic object comprises two or more ions, wherein a second component of the atomic object is one or more ions of a second atomic type (e.g., a second chemical element, an ion of a second atomic number, etc.). In one example embodiment, the first component of the atomic object (ions of the first atomic type) is one or more cooling ions used in a sympathetic cooling scheme for the atomic object. In one example embodiment, the second component of the atomic object (e.g., ions of a second atomic object type) is one or more qubit ions used as qubits in a quantum computer.

[0094] In various embodiments, the atomic objects confined within the atomic object confinement device are used to perform experiments, controlled quantum state evolution, quantum computing, etc. In various embodiments, in order for the atomic objects confined within the atomic object confinement device to perform experiments, controlled quantum state evolution, quantum computing, etc., the atomic objects need to be cryogenic and / or cooled near the motion ground state of the atomic objects and / or their components. In various embodiments, laser cooling is used to reduce the motion energy of the atomic objects and / or their components. For example, in an exemplary embodiment, a first component of the atomic object is cooling ions used for the coordinated cooling of qubit ions, while a second component of the atomic object is qubit ions used as qubits in a quantum computer.

[0095] Conventional types of laser cooling include Doppler cooling and resolved sideband cooling. Doppler cooling involves cooling the atomic object through optical transitions that are wider than its long-term frequency. The long-term frequency of the atomic object is the frequency at which the atomic object oscillates in response to the confinement potential and / or pseudopotential of its confinement device, such as the frequency generated by applying an radio frequency voltage signal to the orbital of a radio frequency electrode and / or a Porro surface ion trap. Doppler cooling is relatively easy to perform but is generally not suitable for cooling the atomic object and / or its components to sufficiently low temperatures. Resolved sideband cooling refers to cooling the atomic object through optical transitions that are narrower than its long-term frequency. However, resolved sideband cooling is technically demanding and requires a relatively high-power laser beam for adequate cooling.

[0096] EIT cooling is another form of laser cooling. EIT cooling involves applying two laser fields and a magnetic field to an atomic object. The laser fields become detuned to the corresponding transitions of the first component of the atomic object. Cooling occurs when stronger photon absorption occurs on the red detuned sideband compared to the blue detuned sideband.

[0097] This paper describes two example EIT cooling operations. The first is an S-to-P-to-D EIT cooling operation, which, for example, can be used for atomic objects where the first component is a single ionized barium (138Ba) atom or another atomic object component with a similar energy structure (e.g., a similar fine structure and / or hyperfine structure, such as a single ionized 88Sr). For example, an S-to-P-to-D EIT cooling operation can be used for atomic objects where the first component has a lower-order D manifold. As used herein, a lower-order D manifold is a state manifold with orbital angular momentum quantum number ℓ = 2, whose energies are respectively lower than those of a state P manifold with angular momentum quantum number ℓ = 1.

[0098] The second example EIT cooling operation described herein is a clock-state EIT cooling operation. For example, a clock-state EIT cooling operation is configured to be used with an atomic object, wherein the first component is a single-ionized ytterbium (e.g., 171Yb) atom or another atomic object component having a similar energy structure (e.g., similar fine structure and / or hyperfine structure). For example, a clock-state EIT cooling operation can be performed with an atomic object, wherein the first component has an electron spin½ and a nuclear spin½. For example, the energy structure of the first component of the atomic object comprises a low-energy manifold comprising two states forming a pair of “clock” states, characterized by the energy difference between the two states being insensitive to magnetic field fluctuations. For example, S in single-ionized 171Yb 1 / 2 F=0, M=0 and S 1 / 2 The F=1, M=0 state is an example of this clock state pair. This clock state pair allows for transitions to common high-energy manifolds, such as the P-manifold in 171Yb, with a linewidth large enough to allow for convenient laser coupling. (Regarding...) Figure 4 In the described example, the clock state is coupled to the P-manifold via σ+ / - transitions. Another exemplary first component of an atomic object with a similar energy structure is a single-ionized 133Ba.

[0099] Exemplary quantum computer system

[0100] Laser cooling of atomic objects confined by atomic object confinement devices can be performed in a variety of environments and / or for a variety of applications. One example background is quantum computing based on quantum charge-coupled devices (QCCDs). Figure 1 A block diagram of an example quantum computer system 100 is provided. In various embodiments, the quantum computer system 100 includes a computing entity 10 and a quantum computer 110.

[0101] In various embodiments, the quantum computer 110 includes a controller 30, a cryogenic and / or vacuum chamber 40 enclosing an atomic object confinement device 50 within which the atomic objects are confined, and one or more manipulation sources 64 (e.g., 64A, 64B, 64C). In one example embodiment, one or more manipulation sources 64 may include one or more lasers (e.g., optical lasers, microwave sources, and / or masers) or another manipulation source. In various embodiments, one or more manipulation sources 64 are configured to manipulate and / or induce controlled quantum state evolution of one or more atomic objects within the device 50. For example, a first manipulation source 64A is configured to generate and / or provide a first manipulation signal, and a second manipulation source 64B is configured to generate and / or provide a second manipulation signal, wherein the first and second manipulation signals are configured to co-laser-cool the atomic objects confined by the atomic object confinement device.

[0102] In various embodiments, the atomic object confinement device 50 is an ion trap, such as a surface ion trap, a Paul ion trap, etc. In various embodiments, the atomic object is an ion, an atom, an ionic crystal, an atomic crystal, etc. In one example embodiment, the atomic object comprises two or more ions, wherein a first component of the atomic object is one or more ions of a first atomic type (e.g., a first chemical element, an ion of a first atomic number, etc.). In one example embodiment, the atomic object comprises two or more ions, wherein a second component of the atomic object is one or more ions of a second atomic type (e.g., a second chemical element, an ion of a second atomic number, etc.). In one example embodiment, the first component of the atomic object (ions of the first atomic type) is one or more cooling ions used in a synergistic cooling scheme for the atomic object. In one example embodiment, the second component of the atomic object (e.g., ions of a second atomic object type) is one or more qubit ions used as qubits in a quantum computer. For example, in one example embodiment, the atomic object is an ionic crystal containing monoionized Ba atoms used as cooling ions and monoionized Yb ions used as qubit ions. In another example embodiment, the atomic object is an ionic crystal containing monoionized Yb atoms used as cooling ions and monoionized Ba ions used as qubit ions.

[0103] In one example embodiment, one or more manipulation sources 64 each provide manipulation signals (e.g., laser beams, etc.) to one or more regions of the atomic object confinement device 50 via a corresponding beam path 66 (e.g., 66A, 66B, 66C). In various embodiments, at least one beam path 66 includes a modulator configured to modulate the manipulation signals provided to the device 50 via the beam path 66. In various embodiments, the manipulation sources 64, modulators, and / or other components of the quantum computer 110 are controlled by a controller 30.

[0104] In various embodiments, the quantum computer 110 includes one or more magnetic field generators 70 (e.g., 70A, 70B). For example, the magnetic field generators may be an internal magnetic field generator 70A disposed within a cryogenic and / or vacuum chamber 40 and / or an external magnetic field generator 70B disposed outside the cryogenic and / or vacuum chamber 40. In various embodiments, the magnetic field generators 70 are permanent magnets, Helmholtz coils, electromagnets, etc. In various embodiments, the magnetic field generators 70 are configured to generate magnetic fields in one or more regions of the atomic object confinement device 50, the magnetic fields having a specific amplitude and a specific magnetic field direction in one or more regions of the atomic object confinement device 50.

[0105] In various embodiments, controller 30 is configured to control voltage sources, electrical signal sources, and / or actuators for controlling the transport of atomic objects within atomic object confinement device 50 and / or atomic object confinement device 50 (cryosystem), and / or cryogenic and / or vacuum systems for controlling temperature and pressure within cryogenic and / or vacuum chamber 40, manipulation source 64, magnetic field generator 70, and / or environmental conditions (e.g., temperature, humidity, pressure, and / or etc.) within cryogenic and / or vacuum chamber 40, and / or other systems configured to manipulate and / or cause controlled evolution of the quantum states of one or more atomic objects within atomic object confinement device 50.

[0106] In various embodiments, computing entity 10 is configured to allow a user to provide input to quantum computer 110 (e.g., through a user interface of computing entity 10) and receive and view output from quantum computer 110, etc. Computing entity 10 can communicate with controller 30 of quantum computer 110 via one or more wired or wireless networks 20 and / or via direct wired and / or wireless communication. In one example embodiment, computing entity 10 can translate, configure, and format information / data, quantum computing algorithms, quantum circuits, etc., into a computing language, executable instructions, command sets, and / or similar content that controller 30 can understand and / or implement.

[0107] Example of EIT cooling operation from S to P to D

[0108] Various embodiments provide quantum computers, systems, devices, etc., and corresponding methods for performing EIT cooling based on two-photon resonant transitions between one or more states of the S-manifold of the first component of the atomic object and one or more states of the P-manifold of the first component of the atomic object and the D-manifold of the first component of the atomic object.

[0109] Typically, EIT cooling of ions with Ba+-like energy structures (e.g., fine and / or hyperfine energy structures similar to single-ionized Ba atoms) involves using a single laser to couple a first state (Zeeman) in the ground-state manifold (e.g., an S-manifold corresponding to angular momentum quantum number ℓ = 0) to an excited state in the stimulated manifold, and to couple the excited state in the stimulated manifold to a second state (Zeeman) in the ground-state manifold (e.g., an S-manifold). In other words, conventional EIT cooling uses two-photon transitions to couple two states within the same manifold.

[0110] However, for atomic objects or their first components with a lower-order D manifold, the atomic object or its first component may become "stuck" in the D manifold. As used herein, a lower-order D manifold is a state manifold with orbital angular momentum quantum number ℓ = 2, whose energies are lower than those of a state P manifold with orbital angular momentum quantum number ℓ = 1. Therefore, conventional EIT cooling requires additional components and steps to efficiently cool atomic objects containing a first component with a lower-order D manifold. Thus, there is a technical problem regarding how to efficiently, effectively, and robustly cool atomic objects to near their motional ground state.

[0111] Various embodiments provide technical solutions to these technical problems. In various embodiments, EIT cooling is performed using a first manipulation signal that couples one or more states of an S-manifold to one or more states of a P-manifold and a second manipulation signal that couples one or more states of a P-manifold to one or more states of a D-manifold. In various embodiments, both the first and second manipulation signals are detuned over one or more states of the P-manifold to establish a dark state associated with a two-photon transition between the S-manifold and the D-manifold. By coupling the S-manifold to the P-manifold and the P-manifold to the D-manifold, efficient cooling to near the motional ground state of the atomic object (e.g., to temperatures significantly below the Doppler cooling limit) can be achieved in a manner with lower laser power requirements than resolved sideband cooling and simpler than conventional EIT cooling techniques. Furthermore, in various embodiments, the first and second manipulation sources used to generate and / or provide the first and second manipulation signals can also be used to perform Doppler cooling. Therefore, various embodiments enable the use of both Doppler cooling and EIT cooling without the need for additional lasers or other manipulation sources. Thus, various embodiments provide a technical improvement over conventional laser cooling of atomic objects comprising a first component having a low D-manifold.

[0112] Furthermore, the detuning amounts in the various embodiments are smaller than those in conventional EIT cooling operations, enabling simultaneous cooling of multiple modes of an atomic object. For example, in the various embodiments, by adjusting the first and second detuning amounts (which, in the various embodiments, are kept substantially equal to each other) and the strengths of the first and second manipulation signals, an optimal set of parameters can be determined for the atomic object to simultaneously cool a wide range of crystal modes of the atomic object with different frequencies (e.g., varying between ~1 MHz and ~3 MHz). For example, the various embodiments provide the additional advantage of being able to simultaneously perform broadband cooling of multiple modes of an atomic object with different mode frequencies (e.g., frequency ranges exceeding 1-3 MHz).

[0113] Figure 2APartial energy level diagrams of an example first component of an atomic object (e.g., cooled ions) illustrating an example EIT cooling operation are provided according to various embodiments. The partial energy level diagrams illustrate an s-manifold 210. In various embodiments, the EIT cooling operation utilizes one or more states of the s-manifold 210 (e.g., one or two states of the s-manifold). The partial energy level diagrams also illustrate a p-manifold 220. In various embodiments, the EIT cooling operation utilizes one or more states of the p-manifold 220 (e.g., one or two states of the p-manifold). The partial energy level diagrams further illustrate a lower-order D-manifold 230. In various embodiments, the EIT cooling operation utilizes one or more states of the D-manifold 230 (e.g., one, two, three, or four states of the D-manifold).

[0114] Figure 2B A partial energy level diagram of an example first component of an atomic object (e.g., a cooled ion) illustrating another example EIT cooling operation according to various embodiments is provided. Figure 2B The partial energy level diagram shown includes... Figure 2A The same S-manifold 210, P-manifold 220, and lower-order D-manifold 230 are shown because, for example, this diagram corresponds to the energy levels of the same cooled ions. However, the polarization of the first manipulation signal 215' used to couple the S-manifold 210 to the P-manifold 220 is... Figure 2B It is σ-polarized, not like... Figure 2A The π polarization shown is illustrated.

[0115] The execution of the EIT cooling operation in various embodiments includes applying first manipulation signals 215, 215' and second manipulation signals 225, 225' to the atomic object. In an example embodiment, the first manipulation signal 215 is characterized by a first wavelength λ1 and is π-polarized, such as... Figure 2A As shown. In another example embodiment, as Figure 2B As shown, the first manipulation signal 215' is characterized by a first wavelength λ1 and is σ-polarized. The first wavelength λ1 corresponds to the transition between the S-manifold 210 and the P-manifold 220. In various embodiments, the first wavelength λ1 corresponds to the resonant frequency of the transition between the S-manifold 210 and the P-manifold 220, and is detuned by a first detuning amount Δ. SP .

[0116] In an example embodiment, the second manipulation signals 225, 225' are characterized by a second wavelength λ2 and are σ-polarized. For example, the second manipulation signal 225 is linearly polarized (σ+ / - polarization) in a direction perpendicular to the magnetic field. The second wavelength λ2 corresponds to the transition between the P-manifold 220 and the D-manifold 230. In various embodiments, the second wavelength λ2 corresponds to the resonant frequency of the transition between the P-manifold 220 and the D-manifold 230, and is detuned by a second detuning amount Δ. PD .

[0117] In various embodiments, when measured for a specific set of three energy levels (one each from the S-manifold, D-manifold, and P-manifold), the first and second detunings are substantially equal to each other (e.g., Δ). SP ≈Δ PD In the example embodiment, the first component of the atomic object is monoionized Ba, the first wavelength λ1 ≈ 493 nm, the second wavelength λ2 ≈ 650 nm, and the first and second detuning amounts Δ SP ≈20MHz≈Δ PD In various embodiments, the frequencies of the first manipulation signals 215, 215' and the frequencies of the second manipulation signals 225, 225' are within tolerance. The internal components are relatively stable to each other. It should be understood that, based on the energy structure of the first component of the atomic object and the selected dark state, various other polarization schemes, wavelengths, and detuning amounts are used in various other embodiments.

[0118] As used in this paper, the term dark state refers to the coherent superposition of two states resulting from appropriate two-photon transitions. For Figure 2A and 2B In the embodiment shown, the corresponding dark state is formed by the superposition of states in the S-manifold and states in the D-manifold, which are coupled through first manipulation signals 215, 215' and second manipulation signals 225, 225'.

[0119] It should be understood that, as used herein, transitions between a first manifold and a second manifold (e.g., S-manifold and P-manifold, P-manifold and D-manifold) indicate transitions between states of the first manifold and states of the second manifold. As used herein, a state manifold refers to a set of states with the same total angular momentum, wherein each manifold comprises multiple states that differ in energy due to Zeeman splitting by an applied magnetic field. The total angular momentum of a state corresponds to the sum of its spin angular momentum and orbital angular momentum (including the nuclear angular momentum through hyperfine coupling when the nuclear angular momentum is non-zero).

[0120] In various embodiments, the EIT cooling operation from S to P to D involves S 1 / 2 Zeeman state of manifold 210, P 1 / 2 Zeeman states of manifold 220 and D 3 / 2 The Zeeman state 230 of the manifold. In an example embodiment, the S-to-P-to-D EIT cooling operation involves states and / or manifolds that tend to be used for Doppler cooling. Therefore, for a system configured to perform Doppler cooling, the same manipulation source can be readily reused in the example embodiment of the S-to-P-to-D EIT cooling operation. Under the finite magnetic field and fixed frequency (e.g., fixed wavelength λ2) of the second manipulation signals 225, 225', scanning the frequency of the first manipulation signals 215, 215' reveals the relationship with the frequency from S. 1 / 2 manifold 210 to D3 / 2 Four dark state resonances are associated with the two-photon resonance transitions of manifold 230. Dark states are states of atomic objects and / or components of atomic objects that cannot absorb or emit photons. When the first wavelength λ1 of the first manipulation signals 215, 215' and the second wavelength λ2 of the second manipulation signals 225, 225' are tuned to one of these two-photon resonances, preferential scattering is induced on the red-sideband transitions that remove kinetic energy from the atomic objects and / or the first components of atomic objects (e.g., cooling ions), and EIT cooling is achieved when the scattering rate of the blue side (e.g., the shorter wavelength, higher frequency side) of the two-photon resonance is less than the scattering rate of the red side (e.g., the longer wavelength, lower frequency side) of the two-photon resonance.

[0121] exist Figure 2A In the diagram, the coupling of the first control signal 215 (shown by solid lines) and the second control signal 225 (shown by solid lines) illustrates the operation of S... 1 / 2 m of manifold 210 j = 1 / 2 states and D 3 / 2 m of manifold 230 j = An example two-photon resonance consisting of 3 / 2 states can be used for EIT cooling operations from S to P to D in the example embodiment.

[0122] The frequency bandwidth of the two-photon resonance depends on P l / 2 The single-photon detuning of the manifold state (e.g., Δ) SP Δ PD For example, as the first and / or second detuning decreases, the width of the two-photon resonance widens, while as the first and / or second detuning increases, the width of the two-photon resonance narrows. The narrower frequency width of the two-photon resonance provides faster cooling to lower temperatures (compared to the wider frequency width of the two-photon resonance), while the wider frequency width of the two-photon resonance provides a wider cooling bandwidth (compared to the narrower frequency width of the two-photon resonance).

[0123] In various embodiments, the first detuning amount Δ SP Second detuning Δ PD The detuning amount is set in the range of 10-450MHz. For example, in one example embodiment, ΔSP = Δ PD ≈ 20 MHz, which provides a sufficiently large cooling bandwidth to effectively cool many motion modes of atomic objects (e.g., ionic crystals, such as ionic crystals containing four ions), while still maintaining a cooling rate and final temperature sufficient for a variety of applications, including cooling atomic objects confined within an atomic object confinement device of a quantum computer, wherein the atomic objects include qubit ions used as qubits in the quantum computer.

[0124] In each embodiment, the first and second detuning amounts ΔSP = Δ PD The smaller first and second detuning amounts (compared to the conventional detuning amounts in conventional EIT cooling operations) of the various embodiments enable the simultaneous cooling of multiple modes of the atomic object. For example, in the various embodiments, by adjusting the first and second detuning amounts (while maintaining Δ in the various embodiments) SP =Δ PD The strengths of the first and second manipulation signals can determine an optimal set of parameters for an atomic object, which can simultaneously cool a wide range of crystal modes of the atomic object with different frequencies (e.g., varying between ~1 MHz and ~3 MHz). For example, various embodiments can simultaneously cool multiple modes of an atomic object with different mode frequencies (e.g., frequency ranges exceeding 1-3 MHz).

[0125] In various embodiments, the efficiency of the various embodiments of the S-to-P-to-D EIT cooling operation is improved when the first and second wavelengths λ1 and λ2, respectively characterizing the first and second manipulation signals, are relatively stable relative to each other. In one example embodiment, the first and second manipulation sources are configured such that the first wavelength λ1 and the second wavelength λ2 are stabilized independently, such that their frequency difference is stabilized to... Tolerances. For example, in one example embodiment, relative stabilization of the first and second wavelengths is performed by independently stabilizing the first and second manipulation sources 64A, 64B. In various embodiments, stabilization of the first and / or second manipulation sources 64A, 64B and / or the first and / or second wavelengths is achieved by using a resonant cavity, coupling the first and second manipulation signals to a frequency comb (examples of which are described in U.S. Patent No. 10,951,002, issued March 16, 2021 (the contents of which are incorporated herein by reference in their entirety)); using servo and / or feedback loops, etc.

[0126] Figure 3A It shows the method for execution Figure 2A An example geometry of the S to P to D EIT cooling operation of the example embodiment shown is illustrated. Figure 3AAn atomic object 308 is shown located and / or arranged in a specific region 55 of the atomic object confinement device 50. The atomic object 308 includes two first components 310 and two second components 312. The first components 310 are of a first atomic type and the second components 312 are of a second atomic type, the first atomic type being different from the second atomic type. For example, in one exemplary embodiment, the first component 310 is a single-ionized Ba atom, and the second component 312 is a single-ionized Yb atom. The first and second components 310, 312 are positioned and / or arranged along an atomic object axis 305 to define the atomic object axis 305. In one exemplary embodiment, the atomic object axis 305 is generally parallel to the radio frequency zero point 350 of the specific region 55 of the atomic object confinement device 50. The radio frequency zero point 350 is the zero line of the pseudopotential generated by applying a radio frequency voltage signal to the radio frequency electrodes and / or tracks of the atomic object confinement device 50.

[0127] In various embodiments, the magnetic field B is generated such that, within a specific region 55, the magnetic field B has a finite and generally stable (e.g., unchanging over time) amplitude (e.g., 2-10 Gauss and / or 5 Gauss in one example embodiment). In various embodiments, the magnetic field B in the specific region 55 has a magnetic field direction forming an angle α with the axis 305 of the atomic object. In one example embodiment, the angle α is 30 to 60 degrees. In one example embodiment, the angle α is approximately 45 degrees.

[0128] In various embodiments, the first manipulation signal 215 has a polarization 218 (e.g., π polarization). In an example embodiment, the polarization 218 of the first manipulation signal 215 is substantially parallel to the magnetic field direction. In various embodiments, the first propagation direction is transverse to the atomic object axis 305. In one example embodiment, the first manipulation signal 215 propagates in a first propagation direction forming an angle β with the atomic object axis 305. In various embodiments, the angle β is configured such that the propagation of the first manipulation signal 215 is not parallel or antiparallel to the magnetic field direction. In various embodiments, the angle β is 30 to 60 degrees. In one example embodiment, the angle β is approximately 45 degrees.

[0129] In various embodiments, the second manipulation signal 225 has a polarization 228 (e.g., σ). + / - (Polarization). In one example embodiment, the polarization 228 of the second manipulation signal 225 is transverse to the magnetic field direction. In various embodiments, the second propagation direction is transverse to the atomic object axis 305. In one example embodiment, the second manipulation signal 225 propagates in a second propagation direction forming an angle γ with the atomic object axis 305. In various embodiments, the angle γ is from 0 to 90 degrees. In one example embodiment, the angle γ is approximately 45 degrees.

[0130] In various embodiments, the first propagation direction and the second propagation direction are substantially antiparallel. In various embodiments, both the first and second propagation directions are transverse to the magnetic field direction. In one example embodiment, the first and second propagation directions are substantially perpendicular to the magnetic field direction.

[0131] Figure 3B It shows how to perform, for example Figure 2B Another example geometry of the S to P to D EIT cooling operation of the example embodiment shown. Figure 3B An atomic object 308 is shown located and / or arranged in a specific region 55 of an atomic object confinement device 50. The atomic object 308 includes two first components 310 and two second components 312. The first components 310 are of a first atomic type and the second components 312 are of a second atomic type, which differs from the first atomic type. For example, in one exemplary embodiment, the first component 310 is a single-ionized Ba atom, and the second component 312 is a single-ionized Yb atom. The first and second components 310, 312 are positioned and / or arranged along an atomic object axis 305 to define the atomic object axis 305. In one exemplary embodiment, the atomic object axis 305 is generally parallel to the radio frequency zero 350 of the specific region 55 of the atomic object confinement device 50.

[0132] In various embodiments, the magnetic field B is generated such that, within a specific region 55, the magnetic field B has a finite and substantially stable (e.g., unchanging over time) amplitude (e.g., 2-10 Gauss and / or 5 Gauss in one example embodiment). In various embodiments, the magnetic field B in the specific region 55 has a magnetic field direction forming an angle α' with the atomic object axis 305. In one example embodiment, the angle α' is 0 to 360 degrees. In one example embodiment, the angle α' is approximately 45 degrees. Specifically, the magnetic field direction is substantially not parallel to or antiparallel to the polarization 228' of the second manipulation signal 225'. In various embodiments, the magnetic field B is substantially parallel to the plane defined by the atomic object confinement device.

[0133] In various embodiments, the first manipulation signal 215' has a first polarization 218' (e.g., σ). + / - (Polarization). In one example embodiment, the first polarization 218' of the first manipulation signal 215' is generally not parallel to and / or transverse to the magnetic field direction. In one example embodiment, the first polarization 218' is perpendicular to the magnetic field direction. In various embodiments, the first propagation direction is transverse to the atomic object axis 305. In one example embodiment, the first manipulation signal 215' propagates in a first propagation direction forming an angle β' with the atomic object axis 305. In various embodiments, the angle β' is from 0 to 90 degrees. In one example embodiment, the angle β' is approximately 45 degrees. In one example embodiment, the angle β' is approximately 90 degrees.

[0134] In various embodiments, the second manipulation signal 225' has a second polarization 228' (e.g., σ). + / - (Polarization). In one example embodiment, the second polarization 228' of the second manipulation signal 225' is transverse to the magnetic field direction. In one example embodiment, the second polarization 228' is perpendicular to the magnetic field direction. In various embodiments, the second propagation direction is transverse to the atomic object axis 305. In one example embodiment, the second manipulation signal 225' propagates in a second propagation direction forming an angle γ with the atomic object axis 305. In various embodiments, the angle γ is 30 to 60 degrees. In one example embodiment, the angle γ is approximately 45 degrees.

[0135] In various embodiments, the first propagation direction is substantially antiparallel to the second propagation direction. In the illustrated embodiment, the first propagation direction and the second propagation direction are substantially antiparallel to each other (e.g., β'≈γ').

[0136] In various embodiments, the first propagation direction (Unit vector in the direction of the wave vector of the corresponding first manipulation signals 215, 215') and the second propagation direction The difference between the unit vectors (in the wave vector direction of the corresponding second manipulation signals 225, 225') has a non-zero projection in the direction of motion to be cooled. For example, when the mode of the atomic object 308 to be cooled is an axial mode (e.g., corresponding to motion along the atomic object axis 305), ,in It is a unit vector along the axis 305 of the atomic object, and In another example, when the mode of the atomic object 308 to be cooled is a radial mode (e.g., corresponding to a motion orthogonal to the atomic object axis 305), ,in It is a radial unit vector (e.g., )and .

[0137] Figure 3A and 3B Two example geometries are shown for performing the S to P to D EIT cooling operation of the example embodiments. It should be understood that other geometries may be used in various other embodiments. For example, in one example embodiment, the magnetic field direction may be parallel or antiparallel to the atomic object axis 305. In one example embodiment, the first propagation direction and the second propagation direction are each parallel to the atomic object axis 305. In various embodiments, the magnetic field direction is transverse to both the first and second propagation directions. In various embodiments, the magnetic field direction, the first propagation direction, and / or the second propagation direction may be transverse to the plane defined by the atomic object restraint device.

[0138] Typically, the S-to-P-to-D EIT cooling operation can be performed using a first manifold, a second manifold, and a third manifold, where each of the first, second, and third manifolds is a different fine-structure manifold. The first and second manifolds are lower-energy manifolds, and both the first and second manifolds can be coupled to the third (higher-energy) manifold via dipole transitions. The illustrated embodiment shows the case where the first manifold is an S-manifold, the second manifold is a D-manifold, and the third manifold is a P-manifold.

[0139] Clock state EIT cooling operation example

[0140] Various embodiments provide quantum computers, systems, devices, etc., and corresponding methods for performing EIT cooling using the clock state of a first component of an atomic object.

[0141] Previously, it had class 171Yb + EIT cooling of ions with energy structures (e.g., fine and / or hyperfine energy structures similar to those of a single-ionized 171Yb atom) is performed by coupling multiple F = 1 states to an excited manifold. For example, by coupling to P 1 / 2 In the states F=0 and m=0, the S of the ground state manifold 1 / 2 The states F = 1 and m = +1 are coupled to the S state of the ground-state manifold. 1 / 2 The state is F = 1 and m = 0. However, S 1 / 2 The coupling from the state F = 1, m = +1 to the state P1 / 2, F = 0, m = 0 requires σ polarization, while S 1 / 2 From state F = 1, m = 0 to P 1 / 2 For F=0 and m=0, π polarization is required, thus necessitating a specific orientation of the magnetic field relative to the propagation direction. Furthermore, ions may become "stuck" in the S... 1 / 2 The state is F=0, m=0, and S must be pumped in again. 1 / 2 For a manifold with F=1, we need to convert S... 1 / 2 The F=0 manifold couples to the additional operating signal of the P manifold. Therefore, conventional EIT cooling requires a high degree of technical complexity to effectively cool atomic objects containing a first component with an energy structure similar to 171Yb+. Furthermore, resolving sideband cooling would require higher bandwidth control than EIT demands, thus necessitating additional technical complexity if both cooling methods are to be used simultaneously. Therefore, a technical problem exists regarding how to efficiently, effectively, and robustly cool atomic objects to near their motional ground state.

[0142] Various embodiments provide technical solutions to these technical problems. In various embodiments, EIT cooling operations are performed using a first manipulation signal that couples a first clock state in the S-manifold of a first component of the atomic object to one or more states in the P-manifold, and a second manipulation signal that couples a second clock state in the S-manifold of the first component of the atomic object to one or more states in the P-manifold. In various embodiments, the first clock state in the S-manifold of the first component of the atomic object is an F = 1, m = 0 state, and the second clock state in the S-manifold of the first component of the atomic object is an F = 0, m = 0 state. The first and second clock states are much less affected by environmental changes compared to the F = 1, m = + / - 1 state. In various embodiments, both the first and second manipulation signals are detuned on one or more states in the P-manifold to establish a dark state associated with the two-photon transition between the first clock state in the S-manifold and the second clock state in the S-manifold.

[0143] By coupling first and second clock states in the S-manifold to generate a dark state, efficient cooling close to the motion ground state of the atomic object (e.g., at temperatures significantly below the Doppler cooling limit) can be achieved. This requires less laser power compared to resolved sideband cooling and is technically simpler than conventional EIT cooling. Furthermore, in various embodiments, the first and second manipulation sources used to generate and / or provide the first and second manipulation signals can also be used to perform sideband cooling of the first component of the atomic object. Therefore, the various embodiments can utilize both sideband cooling and EIT cooling without requiring additional lasers or other manipulation sources.

[0144] Furthermore, the effectiveness of the various embodiments of clock-state EIT cooling operation is insensitive to the relative positioning of the magnetic field and the first and second control signals. Therefore, the various embodiments offer the additional technical advantage of providing efficient cooling without requiring stringent requirements regarding the relative positioning of the magnetic field and the first and second control signals.

[0145] Furthermore, the detuning amounts in the various embodiments are less than those in conventional EIT cooling operations, enabling the simultaneous cooling of multiple modes of an atomic object. For example, the various embodiments offer the additional advantage of being able to simultaneously perform broadband cooling of multiple modes of an atomic object with different mode frequencies (e.g., frequency ranges exceeding 1-3 MHz). Therefore, the various embodiments provide a technical improvement over conventional laser cooling of atomic objects.

[0146] Figure 4Partial energy level diagrams of an example first component of an atomic object (e.g., cooled ions) illustrating example EIT cooling operations according to various embodiments are provided. The partial energy level diagrams illustrate an S-manifold 410. In various embodiments, the EIT cooling operation utilizes two clock states of the S-manifold 410 (e.g., the m=0 state of the S-manifold). The partial energy level diagrams also illustrate a P-manifold 420. In various embodiments, the EIT cooling operation utilizes one or more states of the P-manifold 420. The partial energy level diagrams further illustrate transitions between corresponding clock states and states of the P-manifold 420 with first and second manipulation signals 415, 425 blue detuning of the P-manifold 420.

[0147] The execution of the EIT cooling operation in various embodiments includes applying a first manipulation signal 415 and a second manipulation signal 425 to the atomic object. In one example embodiment, the first manipulation signal 415 is characterized by a first wavelength λ. A It also possesses the first polarization. The first wavelength λ A This corresponds to the transition between the first clock state 412 of the S-manifold 410 and the P-manifold 420. In various embodiments, the first wavelength λ A The resonant frequency corresponding to the transition between the first clock state 412 of the S-manifold 410 and the P-manifold 420, and the first detuning amount Δ from its detuning. A .

[0148] In one example embodiment, the second manipulation signal 425 is characterized by a second wavelength λ. B It also exhibits a second polarization. The second wavelength λ B This corresponds to the transition between the second clock state 414 of the S-manifold 410 and the P-manifold 420. In various embodiments, the second wavelength λ B The resonant frequency corresponding to the transition between the second clock state 414 of the S-manifold 410 and the P-manifold 420, and the second detuning amount Δ from its detuning. B .

[0149] In various embodiments, when measured relative to a specific set of the three energy levels, the first and second detuning amounts are substantially equal to each other (e.g., Δ). A ≈Δ B In one example embodiment, the first component of the atomic object is monoionized Yb, with a first wavelength λ. A The first wavelength is approximately 369.5 nm (e.g., 369.5193 nm), the second wavelength is approximately 369.5 nm (e.g., 369.5251 nm), and the detuning of the first and second wavelengths is Δ. A ≈ 30-450 MHz ≈ Δ B In one example embodiment, Δ A ≈55MHz≈ΔB It should be understood that, based on the energy structure of the first component of the atomic object and the selected dark state, various other polarization schemes, wavelengths, and detunings are used in various other embodiments. In various embodiments, the detuning amount Δ can be adjusted during the execution of clock-state EIT operation. A ≈Δ B This is to cool different (crystal) motion modes of the atomic object. In various embodiments, multiple modes of the atomic object can be cooled simultaneously, including modes of the atomic object with different mode frequencies (e.g., frequency ranges exceeding 1-3 MHz).

[0150] In various embodiments, the first polarization and the second polarization are laterally lateral to each other. For example, in an example embodiment where the first polarization and the second polarization are linearly polarized, the first polarization is laterally lateral to each other along a first direction in which it is positioned and the second polarization is laterally lateral to each other along a second direction in which it is positioned. For example, in one example embodiment, an orthogonal coordinate system is defined such that a first manipulation signal propagates in the positive z-direction, the first polarization is positioned along the x-direction, and a second manipulation signal propagates in the negative z-direction, the second polarization is positioned along the y-direction. In various embodiments, the first polarization and the second polarization can be linear or circularly polarized.

[0151] It should be understood that, as used herein, the first manifold and the second manifold (e.g., S) 1 / 2 F=1 manifold and P 1 / 2 , F=1 manifold, and P 1 / 2 F=1 manifold and S 1 / 2 The transition between states of the first manifold and the second manifold (F=1 manifold) represents the transition between states of the first manifold and the second manifold. As used in this paper regarding clock state EIT cooling operations, the manifold of a state refers to a specific hyperfine level, where each manifold comprises multiple states that are energetically different due to the applied magnetic field via Zeeman splitting.

[0152] The frequency bandwidth of the two-photon resonance depends on P 1 / 2 The state of the manifold (e.g., Δ) A Δ B Detuned single photons. For example, the width of the two-photon resonance widens as the first and / or second detuning amount decreases, while the width of the two-photon resonance narrows as the first and / or second detuning amount increases. The narrower frequency width of the two-photon resonance provides faster cooling to lower temperatures (compared to a wider frequency width of the two-photon resonance), while the wider frequency width of the two-photon resonance provides a wider cooling bandwidth (compared to a narrow frequency width of the two-photon resonance). Various embodiments provide broadband EIT cooling by changing the detuning amount less than conventionally and changing the strength of the first and second manipulation signals to achieve simultaneous cooling of multiple atomic object modes, including atomic object modes with different mode frequencies (e.g., frequency ranges exceeding 1-3 MHz).

[0153] In various embodiments, the first detuning amount Δ A Second detuning Δ B It is set to detuning in the 30-450MHz range. For example, in one example embodiment, Δ A = Δ B ≈ 55 MHz, which provides a sufficiently large cooling bandwidth to effectively cool the motion patterns of atomic objects (e.g., ionic crystals, such as ionic crystals containing four ions) while still maintaining a cooling rate and final temperature sufficient for a variety of applications, including cooling atomic objects confined within an atomic object confinement device of a quantum computer, wherein the atomic objects include qubit ions used as qubits in the quantum computer.

[0154] In various embodiments, when the first and second wavelengths λ, representing the first and second manipulation signals respectively, are... A , λ B The efficiency of various embodiments of the clock-state EIT cooling operation is improved when they are relatively stable relative to each other. In one example embodiment, the first and second manipulation sources are configured such that the first and second wavelengths are stabilized independently. In one example embodiment, the first and second manipulation signals are generated by the same manipulation source 64, such that the respective wavelengths of the two manipulation signals are substantially stable relative to each other.

[0155] exist Figure 4 In the diagram, the coupling of the first control signal 415 (shown by solid lines) and the second control signal 425 (shown by solid lines) illustrates the operation of S... 1 / 2 The m = 0 state of manifold 410 (e.g., clock states 412, 414) and P 1 / 2 An example two-photon resonance composed of the states of manifold 420 can be used in the clock state EIT cooling operation of an exemplary embodiment.

[0156] Figure 4It is also shown that atomic objects are optically pumped out of the Zeeman states 416A, 416B (m = + / - 1) of the S-manifold 10 via a first manipulation signal 415. In various embodiments, spontaneous decay of atomic objects outside the P-manifold 420 can result in filling the uncoupled Zeeman (e.g., m = + / - 1) states 416A, 416B of the S-manifold 410. However, applying the first manipulation signal 415 and the second manipulation signal 425 to the atomic objects also removes population from these uncoupled Zeeman states 416A, 416B, as shown by the dummy transition line 450. For example, applying the first manipulation signal 415 to the atomic objects is optically pumping the atomic objects (e.g., m = + / - 1) states 416A, 416B in the uncoupled Zeeman back to clock states 412, 414. Therefore, any atomic objects that leak from the dark state cooling cycle (e.g., one or more states of clock states 412, 414 and P-manifold 420) will be quickly returned through this optical pumping process.

[0157] In one example embodiment, the first manipulation signal 415 is generated and / or provided by the first manipulation source 64A, and the second manipulation signal 425 is generated and / or provided by the second manipulation source 64B, wherein the first manipulation source 64A and the second manipulation source 64B are different manipulation sources. In one example embodiment, the first manipulation signal 415 and the second manipulation signal 425 are generated by the same manipulation source (e.g., the same laser). For example, in one example embodiment, the first manipulation source and the second manipulation source are the same manipulation source or overlapping manipulation sources (e.g., including the same laser but including different optical components for preparing the respective manipulation signals).

[0158] Figure 5 An example geometry is shown for performing the clock state EIT cooling operation of the example embodiment. Figure 5 An atomic object 508 is shown located and / or arranged in a specific region 55 of an atomic object confinement device 50. The atomic object 508 includes two first components 510 and two second components 512. The first components 510 are of a first atomic type and the second components 512 are of a second atomic type, different from the first atomic type. For example, in one exemplary embodiment, the first component 510 is a single-ionized Yb atom and the second component 512 is a single-ionized Ba atom. The first and second components 510, 512 are positioned and / or arranged along an atomic object axis 505 to define the atomic object axis 505. In one exemplary embodiment, the atomic object axis 505 is substantially parallel to the radio frequency zero point 550 of the specific region 55 of the atomic object confinement device 50. The radio frequency zero point 550 is the zero line of a pseudopotential generated by applying a radio frequency voltage signal to the radio frequency electrodes and / or tracks of the atomic object confinement device 50.

[0159] In various embodiments, a magnetic field B is generated such that, within a specific region 55, the magnetic field B has a finite and generally stable (e.g., does not change over time) amplitude (e.g., 2-10 Gauss and / or 5 Gauss in one example embodiment). In various embodiments, the magnetic field B in the specific region 55 has a magnetic field direction forming an angle θ with the axis 505 of the atomic object. In one example embodiment, the angle θ is in the range of 0 to 90 degrees or in the range of 180 to 270 degrees. In one example embodiment, the angle θ is approximately 45 degrees.

[0160] In various embodiments, the direction of the magnetic field is substantially non-parallel or anti-parallel to the propagation direction of the first manipulation signal 415. In various embodiments, the efficiency of the clock state EIT cooling operation does not depend on the relative angle between the first and second manipulation signals 415, 425 and the magnetic field direction, as long as the magnetic field direction is not substantially parallel or anti-parallel to the polarization 418 of the first manipulation signal 415.

[0161] In various embodiments, the first manipulation signal 415 has a first polarization 418 (e.g., linear polarization in the illustrated embodiment). In an example embodiment, the polarization 418 of the first manipulation signal 415 is transverse to the magnetic field direction.

[0162] In various embodiments, the first manipulation signal 415 propagates in a first propagation direction transverse to the atomic object axis 505. In one example embodiment, the first manipulation signal 415 propagates in the first propagation direction, which forms an angle with the atomic object axis 505. In various embodiments, the angle The angle is between 0 and 90 degrees. In one example embodiment, the angle is... It is approximately 45 degrees.

[0163] In various embodiments, the second manipulation signal 425 has a second polarization 428 (e.g., linear polarization in the illustrated embodiment). In one example embodiment, the second polarization 428 of the second manipulation signal 425 is transverse to the magnetic field direction and the first polarization 418.

[0164] In various embodiments, the second manipulation signal 425 propagates in a second propagation direction transverse to the atomic object axis 505. In one example embodiment, the second manipulation signal 425 propagates in a second propagation direction that forms an angle with the atomic object axis 505. In various embodiments, the angle The angle is between 90 and 180 degrees. In one example embodiment, the angle is... It is approximately 135 degrees.

[0165] In various embodiments, the first propagation direction is transverse to or antiparallel to the second propagation direction. Typically, the first and second propagation directions are substantially non-parallel (e.g., transverse to or antiparallel to each other). In the illustrated embodiments, the first and second propagation directions are substantially antiparallel to each other (e.g., ...). + =180°). In various embodiments, + The temperature ranges from 135 to 225 degrees Celsius.

[0166] In various embodiments, the first propagation direction (Unit vector in the direction of the wave vector of the corresponding first manipulation signal 415) and the second propagation direction The difference between the unit vectors (in the direction of the wave vector of the corresponding second manipulation signal 425) has a non-zero projection in the direction of motion to be cooled. For example, when the mode of the atomic object 508 to be cooled is an axial mode (e.g., corresponding to motion along the axis 505 of the atomic object), ,in It is a unit vector along the axis 505 of the atomic object, and In another example, when the mode of the atom object 508 to be cooled is a radial mode (e.g., corresponding to a motion orthogonal to the axis 505 of the atom object), ,in It is a radial unit vector (e.g., )and .

[0167] Figure 5 An example geometry for performing the clock-state EIT cooling operation of the example embodiment is shown. It should be understood that other geometries may be used in various other embodiments. For example, in one example embodiment, the magnetic field direction may be parallel or antiparallel to the atomic object axis 505. In the example embodiment, a first propagation direction and a second propagation direction are each parallel to the atomic object axis 505. In various embodiments, the magnetic field direction, the first propagation direction, and / or the second propagation direction may be transverse to the plane defined by the atomic object restraint device.

[0168] Example methods for performing EIT cooling operations

[0169] Figure 6 Flowcharts are provided illustrating various processes, procedures, etc., for performing EIT cooling operations from S to P to D and / or clock state EIT cooling operations according to various embodiments. Figure 6 The example embodiments shown correspond to S-to-P-to-D EIT cooling operations and / or clock-state EIT cooling operations performed by a QCCD-based quantum computer (e.g., quantum computer 110). Figure 6The embodiments, processes, programs, etc. shown are executed by the controller 30 of the quantum computer 110.

[0170] Starting from step / operation 602, controller 30 causes quantum computer 110 to begin executing and / or implementing quantum circuitry. For example, controller 30 may control voltage sources, manipulation sources 64, magnetic field generators 70, etc. of quantum computer 110 to cause quantum computer 110 to execute controlled quantum state evolution of qubit ions of atomic objects confined by atomic object confinement device 50.

[0171] In step / operation 604, controller 30 determines that a cooling trigger has been identified. For example, controller 30 determines that a cooling trigger has been identified when it controls quantum computer 110 and / or its components. In one example embodiment, the cooling trigger is identified in response to performing a transfer operation (e.g., linear transfer, transfer through the junction of a two-dimensional atom object confinement device, reordering of components within an atom object, combining atom objects, splitting atom objects, exchanging atom objects, etc.) and determining that excess heat acquired during the transfer operation will be removed from the atom objects. In one example embodiment, the cooling trigger is identified to prepare for the execution of a quantum gate. In various embodiments, various actions and / or planned actions may cause controller 30 to determine that a cooling trigger has been identified. In various embodiments, the cooling trigger indicates a specific region 55 of the atom object confinement device 50 in which a cooling operation will be performed.

[0172] In step / operation 606, controller 30 controls magnetic field generator 70 to generate a magnetic field with a specific direction and amplitude in a specific region 55. In one example embodiment, magnetic field generator 70 is a permanent magnet and controller 30 does not need to control magnetic field generator 70. In one example embodiment, magnetic field generator 70 is configured to generate and / or maintain a generally stable magnetic field with a specific direction and amplitude throughout the operation of quantum computer 110 and / or the execution of quantum circuits and / or algorithms. Therefore, in one example embodiment, controller 30 controls magnetic field generator 70 to maintain a magnetic field with a specific direction and amplitude in a specific region 55.

[0173] In step / operation 608, controller 30 controls first manipulation source 64A to generate first manipulation signals 215 and 415 and provides them to specific area 55, and controls second manipulation source 64B to generate second manipulation signals 225 and 425 and provide them to specific area 55.

[0174] In various embodiments, the EIT cooling operation is an S-to-P-to-D EIT cooling operation, and the first manipulation signal 215 is characterized by a first wavelength λ1, which corresponds to the transition between the S-manifold and P-manifold of the first component 310 of the atomic object 308, and the first detuning amount Δ from the transition between the S-manifold and P-manifold. SP In various embodiments, the second manipulation signal 225 is characterized by a second wavelength λ2, which corresponds to the transition between the P-manifold and D-manifold of the first component 310 of the atomic object 308 and the second detuning amount Δ from the transition between the P-manifold and D-manifold. PD .

[0175] In various embodiments, the EIT cooling operation is a clock-state EIT cooling operation and the first manipulation signal 415 is characterized by a first wavelength λ. A This corresponds to the transition between the first clock state 412 of the S-manifold and the P-manifold 420 of the first component 510 of the atomic object 408, and the first detuning amount Δ from the transition between the first clock state 412 and the P-manifold 420. A In various embodiments, the second manipulation signal 425 is characterized by a second wavelength λ. B This corresponds to the transition between the second clock state 414 of the S-manifold and the P-manifold 420 of the first component 510 of the atomic object 508, and the detuning of the transition between the second clock state 414 and the P-manifold 420 by a second detuning amount Δ. B .

[0176] In various embodiments, the first and second detuning amounts correspond to (e.g., tuned to and / or based on) a (selected) dark state associated with a two-photon transition between the S-manifold and the D-manifold in the case of EIT cooling operation from S to P to D, or correspond to a (selected) dark state associated with a two-photon transition between a first clock state 412 and a second clock state 414 in the case of clock-state EIT cooling operation. In various embodiments, first and second manipulation signals 215, 415, 225, 425 are provided such that an atomic object disposed in a specific region 55 has the first and second manipulation signals incident thereon in a time-overlapping manner. For example, for at least a certain time period, both the first and second manipulation signals are incident on the atomic object disposed in the specific region 55 simultaneously.

[0177] In various embodiments, a Doppler cooling operation is performed before the S-to-P-to-D EIT cooling operation or the clock-state EIT cooling operation. For example, in one example embodiment, a Doppler cooling operation is performed in response to determining that a cooling trigger has been identified, followed by an S-to-P-to-D EIT cooling operation or a clock-state EIT cooling operation, depending on the atomic object and / or its components. In one example embodiment, a cooling trigger is identified in response to determining that a Doppler cooling operation has been performed in a specific region 55 until the atomic object disposed in the specific region 55 has reached the Doppler limit.

[0178] In step / operation 610, controller 30 determines whether sufficient cooling has been performed. For example, controller 30 may control one or more components of quantum computer 110 to perform one or more measurements to determine the temperature and / or motion pattern of an atomic object positioned in a specific region 55. For example, controller 30 may determine whether an S-to-P-to-D EIT cooling operation or a clock-state EIT cooling operation has been performed long enough to cause sufficient cooling. For example, in one example embodiment, controller 30 is configured to perform an S-to-P-to-D EIT cooling operation or a clock-state EIT cooling operation during the cooling time, and determining whether sufficient cooling has been performed is determining whether an S-to-P-to-D EIT cooling operation or a clock-state EIT cooling operation was performed during the cooling time. In various embodiments, the cooling time is 0.2 to 1.5 milliseconds.

[0179] In each embodiment, the S to P to D EIT cooling operation of each embodiment cools the atomic object 308 from the Doppler limit to [temperature value] in less than 1.5 milliseconds. ,in This is the average number of photons in a specific mode of the atomic object. In various embodiments, the S-P-D EIT cooling operation of each embodiment cools the atomic object 308 from the Doppler limit to [a specific value] within 0.2 to 1.25 milliseconds. In one example embodiment, the S-P-D EIT cooling operation of each embodiment cools the atomic object 308 from the Doppler limit to [temperature value] within 0.2 to 0.5 milliseconds. For example, in one example embodiment, the S to P to D EIT cooling operations of the various embodiments cool the atomic object 308 from the Doppler limit to [temperature value] in approximately 0.25 milliseconds. Therefore, the controller 30 can determine whether a cooling time has elapsed since the first and second manipulation signals 215, 225 were first applied to the specific region 55. In various embodiments, the cooling time is 0.25 milliseconds, 0.5 milliseconds, 1 millisecond, 1.25 milliseconds, 1.5 milliseconds, etc.

[0180] In various embodiments, the clock-state cooling operation is configured to cool the atomic object 508 from the Doppler limit to below within approximately 0.7 milliseconds for axial gate mode and approximately 0.13 milliseconds for axial centroid mode. In various embodiments, the clock-state cooling operation is configured to cool all radial modes to [temperature] within less than 0.55 ms. Therefore, controller 30 can determine whether a cooling time has elapsed since the first and second manipulation signals 415, 425 were first applied to the specific region 55. In various embodiments, the cooling time is 0.25 milliseconds, 0.55 milliseconds, 0.8 milliseconds, 1 millisecond, 1.25 milliseconds, etc.

[0181] When it is determined that insufficient cooling has been performed (e.g., the S-to-P-to-D EIT cooling operation or the clock-state EIT cooling operation has been performed for less than the cooling time), the process returns to step / operation 608 and the first and second manipulation signals 215, 225 continue to be applied to the specific region 55. When it is determined that sufficient cooling has been performed (e.g., the S-to-P-to-D EIT cooling operation or the clock-state EIT cooling operation has been performed for the required cooling time), the process continues to step / operation 612.

[0182] In step / operation 612, controller 30 controls the first manipulation source 64A and the second manipulation source 64B to stop the first manipulation signal 215 and the second manipulation signal 225 from being applied to the specific region 55. For example, controller 30 can cause the first manipulation source 64A and / or the second manipulation source 64B to stop generating the first manipulation signal 215 and / or the second manipulation signal 225, respectively. For example, controller 30 can control one or more modulators to stop the first manipulation signal 215 and / or the second manipulation signal 225 from being provided and / or applied to the specific region 55.

[0183] In step / operation 614, controller 30 controls various components of quantum computer 110 (e.g., voltage source, manipulation source 64, magnetic field generator 70, etc.) to continue executing and / or implementing quantum circuits. For example, controller 30 can control various components of quantum computer 110 to cause one or more atomic objects to be transferred into, out of, and / or within a specific region 55, execute one or more quantum gates on one or more atoms, read the state and / or composition of one or more atomic objects, etc.

[0184] Technological advantages

[0185] In various embodiments, an S-to-P-to-D EIT cooling operation is performed. In various embodiments, a system (e.g., a quantum computer) capable of performing S-to-P-to-D EIT cooling and / or a controller configured to cause the corresponding system to perform S-to-P-to-D EIT cooling are provided. For example, various embodiments provide a system in which a first component of an atomic object has a low-order D-manifold and the atomic object is cooled at least partially using an S-to-P-to-D EIT cooling operation. The S-to-P-to-D EIT cooling operations of the various embodiments offer technical advantages over conventional laser cooling techniques and provide technical solutions to technical problems related to conventional laser cooling techniques.

[0186] For example, Doppler cooling can only cool atomic objects to the Doppler limit, which is not low enough for various applications, including QCCD-based quantum computing applications. Furthermore, Doppler cooling is relatively slow compared to EIT cooling. The S-P-D EIT cooling operations of the various embodiments are capable of efficiently cooling atomic objects to well below the Doppler limit (e.g., ...) within a cooling time of 0.2 to 1.5 milliseconds. (≈0.1). While resolved sideband cooling enables cooling below the Doppler limit, it is technically complex to implement, requires high laser power, and is sensitive to fluctuations in laser intensity. Resolved sideband cooling is particularly complex when the atomic object contains multiple components and / or is a crystal containing multiple ions and / or atoms. The S-P-D EIT cooling operations of the various embodiments offer improvements over resolved sideband cooling, including lower implementation complexity and lower laser power requirements, while maintaining fast and efficient cooling performance. The S-P-D EIT cooling operations of the various embodiments further avoid the complexity of performing conventional EIT cooling on components of atomic objects with low-D manifolds. For example, in conventional EIT cooling of atoms and / or ions with low-D manifolds, the atoms and / or ions are likely to be "stuck" in the low-D manifold, requiring re-pumping back into the cooling cycle between the S and P manifolds. Therefore, for atoms and / or ions with low-position D manifolds and / or atomic objects of the first component with low-position D manifolds, the S-to-P-to-D EIT cooling operation of the various embodiments reduces technical complexity compared to conventional EIT cooling.

[0187] The S-to-P-to-D EIT cooling operation of the various embodiments offers the additional technical advantage that the manipulation source used to generate the first and second manipulation signals can be the same manipulation source used to perform Doppler cooling. Therefore, for example, the system can be configured to perform both Doppler cooling and S-to-P-to-D EIT cooling using the same two lasers, which further reduces the technical complexity of implementation in the various embodiments.

[0188] In various embodiments, clock-state EIT cooling operations are performed. In various embodiments, systems (e.g., quantum computers) capable of performing clock-state EIT cooling and / or controllers configured to cause the respective systems to perform clock-state EIT cooling operations are provided. For example, various embodiments provide systems in which a first component of an atomic object has an energy structure similar to that of single-ionized Yb, and the atomic object is cooled at least partially using clock-state EIT cooling operations. The clock-state EIT cooling operations of the various embodiments offer technical advantages over conventional laser cooling techniques and provide technical solutions to technical problems related to conventional laser cooling techniques.

[0189] For example, as discussed elsewhere in this paper, laser cooling is a relatively slow process (e.g., compared to other processes performed by QCCD quantum processors, such as quantum gates, atom object transport, etc.). Furthermore, conventional laser cooling techniques require significant laser power. Additionally, previous EIT cooling of ions with 171Yb+-like energy structures (e.g., fine and / or hyperfine energy structures similar to single-ionized 171Yb atoms) worked by coupling multiple F = 1 states to the excitation manifold. For example, by coupling to P… 1 / 2 In the states of F=0 and m=0, the S of the ground state manifold 1 / 2 The states F = 1 and m = +1 are coupled to the S state of the ground-state manifold. 1 / 2 The states are F = 1 and m = 0. However, S... 1 / 2 The states F = 1 and m = +1 are coupled to the S state of the ground-state manifold. 1 / 2 The states F = 0 and m = 0 require σ-polarization, while S 1 / 2 From state F = 1 and m = 0 to state P 1 / 2 When F=0 and m=0, π polarization is required, thus necessitating a specific orientation of the magnetic field relative to the propagation direction. Furthermore, ions may become "stuck" in S. 1 / 2 The state is F = 0, m = 0, and S must be re-pumped in. 1 / 2 For a manifold with F = 1, we need to convert S... 1 / 2 The additional operational signal for the F = 0 manifold coupling P state. Therefore, conventional EIT cooling requires high technical complexity to effectively cool atomic objects with a first component having an energy structure similar to 171Yb+. Furthermore, resolved sideband cooling would require higher bandwidth control than EIT requires, thus necessitating additional technical complexity if both cooling methods are to be used simultaneously. Therefore, a technical problem exists regarding how to efficiently, effectively, and robustly cool atomic objects to near their motional ground state.

[0190] Various embodiments provide technical solutions to these technical problems. In various embodiments, EIT cooling operations are performed using a first manipulation signal that couples a first clock state in the S-manifold of a first component of the atomic object to one or more states in the P-manifold, and a second manipulation signal that couples a second clock state in the S-manifold of the first component of the atomic object to one or more states in the P-manifold. In various embodiments, the first clock state in the S-manifold of the first component of the atomic object is a F = 0, m = 0 state, and the second clock state in the S-manifold of the first component of the atomic object is a F = 1, m = 0 state. The first and second clock states are less susceptible to environmental changes compared to the F = 1, m = + / - 1 state. In various embodiments, both the first and second manipulation signals are detuned on one or more states in the P-manifold to establish a dark state associated with a two-photon transition between the first clock state in the S-manifold and the second clock state in the S-manifold. By coupling first and second clock states in an S-manifold to generate a (selected) dark state, efficient cooling close to the motion ground state of the atomic object (e.g., temperatures significantly below the Doppler cooling limit) can be achieved, requiring less laser power compared to resolved sideband cooling and being technically simpler than conventional EIT cooling. Furthermore, in various embodiments, the first and second manipulation sources used to generate and / or provide the first and second manipulation signals can also be used to perform sideband cooling of a first component of the atomic object. Therefore, the various embodiments can utilize both sideband cooling and EIT cooling without requiring additional lasers or other manipulation sources. Moreover, compared to conventional laser cooling techniques, the various embodiments result in faster cooling of the atomic object while using less power. Therefore, the various embodiments provide a technical improvement over conventional laser cooling of atomic objects.

[0191] Example Controller

[0192] In various embodiments, the quantum computer 110 includes a controller 30 configured to control various elements of the quantum computer 110. In various embodiments, the controller 30 may be configured to cause the quantum computer 110 to perform various operations (e.g., computational operations such as gate operations, cooling operations, transfer operations, qubit interaction operations, qubit measurement operations, leakage suppression / conversion operations, etc.). For example, the controller 30 may be configured to recognize cooling triggers, causing the execution of cooling operations (e.g., S-to-P-to-D EIT cooling operations, clock-state EIT cooling operations, and / or Doppler cooling, followed by S-to-P-to-D or clock-state EIT cooling operations), control first and / or second manipulation sources to provide first and / or second manipulation signals, etc. For example, controller 30 may be configured to control cryogenic and / or vacuum systems, control temperature and pressure within cryogenic and / or vacuum chamber 40, manipulation source 64, voltage source configured to apply voltage signals to electrodes of atomic object confinement device 50, magnetic field generator 70, and / or control environmental conditions (e.g., temperature, humidity, pressure, etc.) within cryogenic and / or vacuum chamber 40, and / or be configured to manipulate and / or cause the controlled evolution of the quantum states of one or more atomic objects within atomic object confinement device 50.

[0193] like Figure 7 As shown, in various embodiments, controller 30 may include various controller elements, including processing element 705, memory 710, driver controller element 715, communication interface 720, analog-to-digital converter element 725, etc. For example, processing element 705 may include programmable logic device (CPLD), microprocessor, coprocessor entity, application-specific instruction set processor (ASIP), integrated circuit, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), programmable logic array (PLA), hardware accelerator, other processing devices and / or circuits, etc., and / or controllers. The term circuit can refer to a completely hardware embodiment or a combination of hardware and computer program products. In one example embodiment, processing element 705 of controller 30 includes a clock and / or communicates with a clock.

[0194] For example, memory 710 may include non-transient memory, such as volatile memory, and / or non-volatile memory, such as one or more of the following: hard disk, ROM, PROM, EPROM, EEPROM, flash memory, MMC, SD memory card, Memory Stick, CBRAM, PRAM, FeRAM, RRAM, SONOS, track memory, RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM, RDRAM, RIMM, DIMM, SIMM, VRAM, cache memory, register memory, etc. In various embodiments, memory 710 may store qubit records corresponding to qubits of a quantum computer (e.g., in qubit record data storage, qubit record database, qubit record table, etc.), calibration tables, executable file queues, computer program code (e.g., in one or more computer languages, one or more dedicated controller languages, etc.), etc. In one example embodiment, execution of at least a portion of the computer program code stored in memory 710 (e.g., via processing element 705) causes controller 30 to perform one or more steps, operations, processes, programs, etc., as described herein.

[0195] In various embodiments, the driver controller element 715 may include one or more driver and / or controller elements, each configured to control one or more drivers. In various embodiments, the driver controller element 715 may include drivers and / or driver controllers. For example, a driver controller may be configured to cause one or more corresponding drivers to operate according to executable instructions, commands, etc., scheduled and executed by the controller 30 (e.g., by the processing element 505). In various embodiments, the driver controller element 715 may enable the controller 30 to operate and / or control one or more manipulation sources 64, control one or more magnetic field generators 70, operate vacuum and / or cryogenic systems, etc. In various embodiments, the driver may be a laser driver; a vacuum component driver; a voltage source (e.g., an AC voltage source, an arbitrary waveform generator (AWG), a direct digital synthesizer (DDS), etc.); a cryogenic and / or vacuum system component driver, etc. In various embodiments, the controller 30 includes means for communicating and / or receiving signals from one or more optical receiver components, such as cameras, MEMS cameras, CCD cameras, photodiodes, photomultiplier tubes, etc. For example, controller 30 may include one or more analog-to-digital converter elements 725 configured to receive signals from one or more optical receiver components, calibration sensors, etc. For example, controller 30 may receive, via analog-to-digital converter elements 725, conditions corresponding to a specific region 55 of atomic object confinement device 50 and / or measurements corresponding to various atomic objects 308.

[0196] In various embodiments, the controller 30 may include a communication interface 720 for interfacing with and / or communicating with the computing entity 10. For example, the controller 30 may include the communication interface 720 for receiving executable instructions, command sets, etc., from the computing entity 10, and providing the computing entity 10 with outputs received from the quantum computer 110 (e.g., from an optical collection system or other measurement system), and / or the processed results of those outputs. In various embodiments, the computing entity 10 and the controller 30 may communicate via a direct wired and / or wireless connection and / or one or more wired and / or wireless networks 20.

[0197] Exemplary computing entity

[0198] Figure 8Illustrative schematics are provided representing an example computing entity 10 that can be used in conjunction with embodiments of the present invention. In various embodiments, computing entity 10 is configured to allow a user to provide input to quantum computer 110 (e.g., through a user interface of computing entity 10) and to receive, display, analyze, and / or similarly process output from computer 110. For example, a user can operate computing entity 10 to generate and / or program quantum algorithms and / or quantum circuits, which can be provided such that controller 30 can receive the quantum algorithms and / or quantum circuits and cause quantum computer 110 to execute the quantum algorithms and / or quantum circuits.

[0199] like Figure 8As shown, computing entity 10 may include an antenna 812, a transmitter 814 (e.g., a radio), a receiver 806 (e.g., a radio), and processing means and / or elements 808 for providing signals to and receiving signals from the transmitter 814 and receiver 806, respectively. The signals provided to and received from the transmitter 814 and receiver 806 may include signaling information / data according to the air interface standard of the applicable wireless system for communication with various entities such as controller 30, other computing entities 10, etc. In this respect, computing entity 10 may be able to operate using one or more air interface standards, communication protocols, modulation types, and access types. For example, computing entity 10 may be configured to receive and / or provide communication using wired data transmission protocols such as Fiber Distributed Data Interface (FDDI), Digital Subscriber Line (DSL), Ethernet, Asynchronous Transfer Mode (ATM), Frame Relay, Cable Data Service Interface Specification (DOCSIS), or any other wired transmission protocol. Similarly, computing entity 10 can be configured to communicate via a wireless external communication network using any of a variety of protocols, such as General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), CDMA2000 1X (1xRTT), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile Communications (GSM), Enhanced Data Rate Evolution of GSM (EDGE), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Evolved Data Optimized (EVDO), High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), IEEE 802.11 (Wi-Fi), Wi-Fi Direct, 802.16 (WiMAX), Ultra Wideband (UWB), Infrared (IR) protocol, Near Field Communication (NFC) protocol, Wibree, Bluetooth protocol, Wireless Universal Serial Bus (USB) protocol, and / or any other wireless protocol.Computing entity 10 can use protocols and standards such as Border Gateway Protocol (BGP), Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), File Transfer Protocol (FTP), Hypertext Transfer Protocol (HTTP), HTTPS / SSL / encryption protocol, Internet Message Access Protocol (IMAP), Network Time Protocol (NTP), Simple Mail Transfer Protocol (SMTP), Telnet, Transport Layer Security (TLS), Secure Sockets Layer (SSL), Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Datagram Congestion Control Protocol (DCCP), Stream Control Transfer Protocol (SCTP), and Hypertext Markup Language (HTML) to communicate.

[0200] Through these communication standards and protocols, computing entity 10 can communicate with various other entities using concepts such as Unstructured Supplemental Service Message / Data (USSD), Short Message Service (SMS), Multimedia Messaging Service (MMS), Dual-Tone Multi-Frequency Signaling (DTMF), and / or Subscriber Identity Module Dialer (SIM Dialer). Computing entity 10 can also download changes, add-ons, and updates to its firmware, software (e.g., including executable instructions, applications, program modules), and operating system.

[0201] The computing entity 10 may also include user interface devices, which include one or more user input / output interfaces (e.g., a display 816 and / or a speaker / speaker driver coupled to the processing device and / or element 808, and a touchscreen, keyboard, mouse, and / or microphone coupled to the processing device and / or element 808). For example, the user output interface may be configured to provide an application, browser, user interface, interface, dashboard, screen, webpage, page, and / or similar terms interchangeably used herein, which execute on or can be accessed by the computing entity 10 to cause information / data to be displayed or heard and interacted with via one or more user input interfaces. The user input interface may include any of a plurality of devices that allow the computing entity 10 to receive data, such as a keypad 818 (hard or soft), a touch display, a voice / speech or motion interface, a scanner, a reader, or other input device. In embodiments including a keypad 818, the keypad 818 may include (or cause to display) regular numbers (0-9) and related keys (#, *), as well as other keys for operating the computing entity 10, and may include a full set of letter keys or a set of keys that can be activated to provide a full set of alphanumeric keys. In addition to providing input, the user input interface can also be used, for example, to activate or deactivate certain functions, such as a screen saver and / or sleep mode. Through such input, the computing entity 10 can collect information / data, user interactions / inputs, etc.

[0202] The computing entity 10 may also include volatile memory or storage 822 and / or non-volatile memory or storage 824, which may be built-in and / or removable. For example, non-volatile memory may be ROM, PROM, EPROM, EEPROM, flash memory, MMC, SD memory card, Memory Stick, CBRAM, PRAM, FeRAM, RRAM, SONOS, racetrack memory, etc. Volatile memory may be RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM, RDRAM, RIMM, DIMM, SIMM, VRAM, cache memory, register memory, etc. Both volatile and non-volatile memory or storage may store databases, database instances, database management system entities, data, applications, programs, program modules, scripts, source code, object code, bytecode, compiled code, interpreted code, machine code, executable instructions, etc., to implement the functions of the computing entity 10.

[0203] Conclusion

[0204] Benefiting from the teachings presented in the foregoing description and the accompanying drawings, those skilled in the art will conceive of many modifications and other embodiments of the invention set forth herein. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

[0205] The following additional terms are part of the instruction manual:

[0206] 1. A method for cooling an atomic object confined by an atomic object confining device, the method comprising:

[0207] A first manipulation source is controlled via a controller associated with the atomic object limiting device to provide a first manipulation signal to a specific area of ​​the atomic object limiting device; and

[0208] The controller controls a second manipulation source to provide a second manipulation signal to a specific region of the atomic object confinement device.

[0209] in:

[0210] The atomic object to be cooled is located in a specific region of the atomic object confinement device.

[0211] The first manipulation signal is characterized by a first wavelength, which corresponds to a first transition between a first clock state of the S-manifold and a first transition of the first component of the atomic object in the P-manifold, and a first detuning amount from the first transition.

[0212] The second manipulation signal is characterized by a second wavelength corresponding to a second transition between the second clock state of the S-manifold and the P-manifold of the first component of the atomic object, and a second detuning amount from the second transition.

[0213] The first detuning amount and the second detuning amount are selected to establish a dark state associated with the two-photon transition between the first clock state and the second clock state.

[0214] 2. According to the method of Project 1, wherein the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0215] 3. The method according to Project 2, wherein the first component of the atomic object is configured as a cooling ion in a synergistic cooling scheme for the ionic crystal.

[0216] 4. The method according to Project 2, wherein the second component of the atomic object is at least one of two or more ions of a second atomic object type, the second atomic object type being different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including the atomic object confinement device.

[0217] 5. According to the method described in Project 2, wherein the first atomic object type is a single-ionized ytterbium.

[0218] 6. According to the method described in Project 1, the first detuning amount and the second detuning amount are approximately equal.

[0219] 7. The method according to Project 1 further includes generating a magnetic field with a magnetic field direction in a specific region of the atomic object confinement device, the magnetic field direction being transverse to the propagation direction of the first manipulation signal.

[0220] 8. The method according to item 1, wherein the first manipulation signal is characterized by a first polarization, which is a linear polarization substantially parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization substantially perpendicular to the plane defined by the atomic object.

[0221] 9. The method according to item 8 further includes generating a magnetic field with a magnetic field direction in a specific region of the atomic object confinement device, wherein the magnetic field direction is transverse to the first polarization.

[0222] 10. The method according to Project 1, wherein the first manipulation signal is characterized by a first polarization, the second manipulation signal is characterized by a second polarization, and the first polarization is transverse to the second polarization.

[0223] 11. According to the method described in Project 1, wherein the first clock state is F=1, m=0, and the second clock state is F=0, m=0.

[0224] 12. An apparatus comprising at least one processor and a memory storing computer-executable instructions, the computer-executable instructions being configured to, when executed by the at least one processor, cause the apparatus to at least:

[0225] Controlling a first manipulation source to provide a first manipulation signal to a specific region of the atomic object confinement device; and

[0226] Control the second manipulation source to provide a second manipulation signal to a specific region of the atomic object confinement device.

[0227] in:

[0228] The atomic object to be cooled is located in a specific region of the atomic object confinement device.

[0229] The first manipulation signal is characterized by a first wavelength, which corresponds to a first transition between a first clock state of the S-manifold and a first transition of the first component of the atomic object in the P-manifold, and a first detuning amount from the first transition.

[0230] The second manipulation signal is characterized by a second wavelength corresponding to a second transition between the second clock state of the S-manifold and the P-manifold of the first component of the atomic object, and a second detuning amount from the second transition.

[0231] The first detuning amount and the second detuning amount are selected to establish a dark state associated with the two-photon transition between the first clock state and the second clock state.

[0232] 13. The apparatus according to item 12, wherein the atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

[0233] 14. The apparatus according to item 13, wherein a first component of the atomic object is configured as a cooling ion in a synergistic cooling scheme for the ionic crystal, and is either a single-ionized ytterbium or has an energy level structure similar to that of a single-ionized ytterbium.

[0234] 15. The apparatus according to item 13, wherein the second component of the atomic object is at least one of two or more ions of a second atomic object type, the second atomic object type being different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including the atomic object confinement apparatus.

[0235] 16. The apparatus according to item 12, wherein the first detuning amount and the second detuning amount are approximately equal.

[0236] 17. The apparatus according to item 12, wherein a magnetic field with a magnetic field direction exists in a specific region of the atomic object confinement device, and the magnetic field direction is transverse to the propagation direction of the first manipulation signal.

[0237] 18. The apparatus according to item 12, wherein the first manipulation signal is characterized by a first polarization, which is a linear polarization substantially parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization substantially perpendicular to the plane defined by the atomic object, wherein a magnetic field having a magnetic field direction exists in a specific region of the atomic object limiting device, and the magnetic field direction is transverse to the first polarization.

[0238] 19. The apparatus according to item 12, wherein the first clock state is F=1, m=0, and the second clock state is F=0, m=0.

[0239] 20. A system comprising:

[0240] An atomic object limiting device, configured to limit an atomic object to a specific region of the atomic object limiting device;

[0241] A first manipulation source, which can be controlled by the controller of the system and configured to provide a first manipulation signal to a specific region of the atomic object confinement device;

[0242] A second manipulation source, which can be controlled by the system's controller and configured to provide a second manipulation signal to a specific region of the atomic object confinement device; and

[0243] The controller includes at least one processor and a memory storing computer-executable instructions configured such that, when executed by the at least one processor, the controller at least:

[0244] Controlling a first manipulation source to provide a first manipulation signal to a specific region of the atomic object confinement device; and

[0245] Control the second manipulation source to provide a second manipulation signal to a specific region of the atomic object confinement device.

[0246] in:

[0247] The atomic object to be cooled is located in a specific region of the atomic object confinement device.

[0248] The first manipulation signal is characterized by a first wavelength, which corresponds to a first transition between a first clock state of the S-manifold and a first transition of the first component of the atomic object in the P-manifold, and a first detuning amount from the first transition.

[0249] The second manipulation signal is characterized by a second wavelength corresponding to a second transition between the second clock state of the S-manifold and the P-manifold of the first component of the atomic object, and a second detuning amount from the second transition.

[0250] The first detuning amount and the second detuning amount are selected to establish a dark state associated with the two-photon transition between the first clock state and the second clock state.

Claims

1. A method for cooling an atomic object confined by an atomic object confining device, the method comprising: A first manipulation source is controlled by a controller associated with the atomic object limiting device to provide a first manipulation signal to a specific area of ​​the atomic object limiting device; and The controller controls a second manipulation source to provide a second manipulation signal to a specific region of the atomic object confinement device. in: The atomic object to be cooled is located in a specific region of the atomic object confinement device. The first manipulation signal is characterized by a first wavelength, which corresponds to a first transition between a first clock state of the S-manifold and a first transition of the first component of the atomic object in the P-manifold, and a first detuning amount from the first transition. The second manipulation signal is characterized by a second wavelength, which corresponds to a second transition between the second clock state of the S-manifold and the P-manifold of the first component of the atomic object, and a second detuning amount from the second transition. The first detuning amount and the second detuning amount are selected to establish a dark state associated with the two-photon transition between the first clock state and the second clock state.

2. The method according to claim 1, wherein, The atomic object is an ionic crystal comprising two or more ions, and the first component of the atomic object is at least one of two or more ions of a first atomic object type.

3. The method according to claim 2, wherein, The first component of the atomic object is configured as a cooling ion in a synergistic cooling scheme for the ionic crystal.

4. The method according to claim 2, wherein, The second component of the atomic object is at least one of two or more ions of a second atomic object type, which is different from the first atomic object type, and wherein at least one of the two or more ions of the second atomic object type is configured as a qubit of a quantum computer including the atomic object confinement device.

5. The method according to claim 2, wherein, The first atom object type is a single-ionized ytterbium.

6. The method according to claim 1, wherein, The first detuning amount and the second detuning amount are equal.

7. The method of claim 1, further comprising generating a magnetic field having a magnetic field direction in a specific region of the atomic object confinement device, the magnetic field direction being transverse to the propagation direction of the first manipulation signal.

8. The method according to claim 1, wherein, The first manipulation signal is characterized by a first polarization, which is a linear polarization parallel to the plane defined by the atomic object limiting device, and the second manipulation signal is characterized by a second polarization, which is a linear polarization perpendicular to the plane defined by the atomic object.

9. The method of claim 8, further comprising generating a magnetic field having a magnetic field direction in a specific region of the atomic object confinement device, wherein, The direction of the magnetic field is transverse to the first polarization.

10. The method according to claim 1, wherein, The first manipulation signal is characterized by a first polarization, and the second manipulation signal is characterized by a second polarization, wherein the first polarization is transverse to the second polarization.

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