Laser cooling on a dipole raman transition using a spatially structured optical field

Abstract

A system for performing sympathetic laser cooling is provided. The system includes a confinement apparatus configured to confine an object crystal that includes a qubit object and a coolant object in a cooling area. The system further includes manipulation sources configured to generate first and second manipulation signals. When the first and second manipulation signals are applied to the coolant object, the first and second manipulation signals collectively drive a sideband transition of the coolant object between a first quantum state and a second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal. The system further includes one or more beam path systems that provide the first and second manipulation signals to the cooling area and one of the first or second manipulation signal is provided as a spatially structured optical field within the cooling area.

Description

LASER COOLING ON A DIPOLE RAMAN TRANSITION USING A SPATIALLY STRUCTURED OPTICAL FIELDCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Application No. 19 / 169,421, filed April 3, 2025, which claims priority to U.S. Application No. 63 / 738,651, filed December 24, 2024, and U.S. Application No. 63 / 640,027, filed April 29, 2024, the contents of which are incorporated herein by reference in their entireties.TECHNICAL FIELD

[0002] Embodiments described herein generally relate to laser cooling an atomic object using a spatially structured optical field. For example, some embodiments relate to sympathetic laser cooling using a spatially structured optical field.BACKGROUND

[0003] Various quantum and / or atomic systems using laser cooling to cool quantum and / or atomic objects. In various quantum and / or atomic systems, a quantum and / or atomic object used for performance of experiments and / or storing of quantum information (e.g., used as a qubit object) is confined in an object crystal with a coolant object. Sympathetic laser cooling is then used to cool the quantum and / or atomic object used for performance of experiments and / or storing of quantum information by addressing the coolant object with one or more laser beams. However, such sympathetic laser cooling processes take a significant amount of time. For example, for an example quantum computer that uses sympathetic laser cooling to cool qubit objects in preparation of performance of quantum operations (e.g., quantum logic gates) on the qubit objects, performance of a sympathetic laser cooling process may require twenty times as much time as performance of a quantum operation. Through applied effort, ingenuity, and innovation many deficiencies of such systems have been solved by developing solutions that are structured in accordance with the embodiments of the present invention, many examples of which are described in detail herein.BRIEF SUMMARY OF EXAMPLE EMBODIMENTS

[0004] Example embodiments provide methods for performing laser cooling using a spatially structured optical field and quantum computers, systems, controllers, computer program products, and / or apparatus configured for performing laser cooling using a spatially structured optical field.

[0005] In various embodiments, an object crystal is confined by a confinement apparatus. The object crystal includes at least one qubit object and at least one coolant object that are confined within the same potential well. The object crystal is confined such that the coolant object is located at a target location defined at least in part by the confinement apparatus. A first manipulation signal and a second manipulation signal are caused to be incident on the object crystal and / or the coolant object. The first manipulation signal is red detuned from a first transition between a first quantum state of the coolant object and an excited state of the coolant object and the second manipulation is red detuned from a second transition between a second quantum state of the coolant object and the excited state of the coolant object. When the first manipulation signal and the second manipulation signal are applied to the coolant object, the first manipulation signal and the second manipulation signal collectively drive at least one sideband transition of the coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal. The first manipulation signal is provided to the cooling area as a spatially structured optical field. In various embodiments, the target location, at which the coolant object is located, is disposed at an intensity minimum and / or null of the spatially structured optical field. In certain embodiments, an object crystal includes multiple coolant objects that are each confined at respective intensity minima and / or nulls of the spatially structured optical field.

[0006] According to a first aspect, a system configured for performing sympathetic laser cooling is provided. In an example embodiment, the system includes a confinement apparatus configured to confine an object crystal comprising at least one qubit object and at least one coolant object with the at least one coolant object located at a target location within a cooling area defined at least in part by the confinement apparatus. The system further includes one or more manipulation sources configured to generate a first manipulation signal and a second manipulation signal. The first manipulation signal is red detuned from a first transition between a first quantum state of the at least one coolant object and an excited state of the at least one coolant object and the secondmanipulation is red detuned from a second transition between a second quantum state of the at least one coolant object and the excited state of the at least one coolant object such that when the first manipulation signal and the second manipulation signal are applied to the at least one coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal. The system further includes one or more beam path systems. The one or more beam path systems define one or more beam paths configured to provide the first manipulation signal and the second manipulation signal to the cooling area and one of the first manipulation signal or the second manipulation signal is provided by the one or more beam path systems as a spatially structured optical field within the cooling area.

[0007] For example, the first manipulation signal and the second manipulation signal may be configured to perform laser cooling on the object crystal via a dipole Raman transition of the at least one coolant object that is characterized by a detuning that corresponds to respective motional mode frequencies corresponding to one or more motional modes of the object crystal.

[0008] In an example embodiment, the target location at which the at least one coolant object is confined is located at an intensity minima of the spatially structured optical field.

[0009] In an example embodiment, a gradient of the first optical field at the target location is non-zero.

[0010] In an example embodiment, the spatially structured optical field is a spatial phase stable optical field such that a spatial phase of the first optical field is stable in time within the cooling area while the first manipulation signal is being provided to the cooling area.

[0011] In an example embodiment, the motional mode frequency corresponds to a motional mode corresponding to movement of the object crystal, the at least one qubit object and / or the at least one coolant object along a corresponding motional mode axis.

[0012] In an example embodiment, the one or more beam paths are configured to provide the first manipulation signal and the second manipulation signal such that a gradient of an amplitude / magnitude of the spatially structured optical field has a non-zero projection onto the motional mode axis of the motional mode at the target location.

[0013] In an example embodiment, the spatially structured optical field is a standing wave characterized by a spatial phase that evolves along an axis which has a non-zero projection along the corresponding motional mode axis.

[0014] In an example embodiment, the first manipulation signal is provided to the cooling area as a travelling wave characterized by a higher-order optical mode having at least one stable intensity minima.

[0015] In an example embodiment, the red effective detuning corresponds to at least one motional mode frequency corresponding to a motional mode of the object crystal.

[0016] In an example embodiment, the red effective detuning is configured to enable effective cooling of more than one motional mode of the object crystal.

[0017] In an example embodiment, the one or more beam paths are configured to provide the first manipulation signal and the second manipulation signal such that a gradient of an amplitude / magnitude of the spatially structured optical field has a first non-zero projection onto a first motional mode axis corresponding to a first motional mode of the object crystal and has a second non-zero projection onto a second motional mode axis corresponding to a second motional mode of the object crystal.

[0018] In an example embodiment, the first motional mode axis is substantially perpendicular to the second motional mode axis.

[0019] In an example embodiment, one or more components of the one or more beam path systems is an optical component that is housed on a first substrate that houses the confinement apparatus or housed on a second substrate that is secured in relation to the first substrate.

[0020] For example, the one or more components may be integrated photonic components that are integrated with a first substrate housing the confinement apparatus or a second substrate that is secured in relation to the first substrate.

[0021] In an example embodiment, the at least one component of the one or more components is configured to cause an optical mode of the first manipulation signal to be a higher-order optical mode having a stable intensity minima.

[0022] In an example embodiment, the at least one component is configured to provide the first manipulation signal to the cooling area in a direction that is not co-linear or not aligned to a motional mode axis corresponding to the motional mode frequency.

[0023] In an example embodiment, the one or more components comprises a first component configured to cause a first portion of the first manipulation signal to be provided to the cooling area in a first direction and a second component configured to cause a second portion of the first manipulation signal to be provided to the cooling area in the second direction such that a difference wave vector between the first portion of the first manipulation signal and the second portion of the first manipulation signal has a non-zeroprojection along a motional mode axis corresponding to a motional mode of the object crystal.

[0024] In an example embodiment, the one or more beam path systems define a first source beam path configured to direct the first manipulation signal from a first manipulation source of the one or more manipulation sources and that generated the first manipulation signal to a beam splitter configured to split the first manipulation signal into the first portion and the second portion, a first beam path configured to provide the first portion to the first component, and a second beam path configured to provide the second portion to the second component.

[0025] In an example embodiment, the one or more components comprise a third component configured to provide the second manipulation signal to the cooling area.

[0026] In an example embodiment, the one or more beam path systems define a second source beam path configured to direct the second manipulation signal from a second manipulation source of the one or more manipulation sources and that generated the second manipulation signal to the third component.

[0027] In an example embodiment, the system is a quantum charge-coupled device (QCCD)-based quantum computer.

[0028] According to another aspect, a method for performing sympathetic laser cooling is provided. In an example embodiment, the method includes controlling operation of a confinement apparatus to cause an object crystal comprising at least one qubit object and at least one coolant object to be confined within a cooling area with the at least one coolant object confined at a target location defined at least in part by the confinement apparatus. The method further includes controlling operation of one or more manipulation sources and, optionally, one or more beam path systems, to cause a first manipulation signal and a second manipulation signal to start to be provided to the cooling area. The first manipulation signal is red detuned from a first transition between a first quantum state of the at least one coolant object and an excited state of the at least one coolant object and the second manipulation is red detuned from a second transition between a second quantum state of the at least one coolant object and the excited state of the at least one coolant object such that when the first manipulation signal and the second manipulation signal are applied to the at least one coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of theobject crystal, and one of the first manipulation signal or the second manipulation signal is provided to the cooling area as a spatially structured optical field.

[0029] In an example embodiment, the target location at which the at least one coolant object is confined is located at an intensity minima of the spatially structured optical field.

[0030] In an example embodiment, a gradient of the first optical field at the target location is non-zero.

[0031] In an example embodiment, wherein the method further includes, responsive to determining that the first manipulation signal and the second manipulation signal have been provided to the cooling area for a cooling time, controlling operation of the one or more manipulation sources, and optionally, the one or more beam path systems, to cause the first manipulation signal and the second manipulation to stop being provided to the cooling area.

[0032] In an example embodiment, the spatially structured optical field is one of a spatial phase stable optical field such that a spatial phase of the first optical field is stable in time within the cooling area while the first manipulation signal is being provided to the cooling area, or a higher-order optical mode having a stable intensity minima.

[0033] In an example embodiment, the motional mode frequency corresponds to at least one motional mode corresponding to movement of the object crystal, the at least one qubit object and / or the at least one coolant object along a corresponding motional mode axis.

[0034] In an example embodiment, wherein the one or more beam paths are configured to provide the first manipulation signal and the second manipulation signal such that a gradient of an amplitude / magnitude of the spatially structured optical field has a nonzero projection onto the motional mode axis of the motional mode at the target location.

[0035] In an example embodiment, the spatially structured optical field is one of a standing wave characterized by a spatial phase that evolves substantially along an axis which has a non-zero projection along the corresponding motional mode axis, or a travelling wave characterized by a higher-order optical mode and propagating in a direction that is not co-linear or not aligned to the motional mode axis.

[0036] According to another aspect, a controller of a system disclosed herein is provided. The controller is configured to perform a method disclosed herein to sympathetically cool a qubit object via laser cooling of a coolant object in an object crystal with the qubit object via laser cooling using a spatially structured optical field.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0037] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0038] Figure 1 provides block diagram of an example QCCD-based quantum computer, in accordance with an example embodiment.

[0039] Figure 2 A provides a partial energy structure diagram of a coolant object, according to an example embodiment.

[0040] Figure 2B provides a partial energy structure diagram illustrating a sideband cooling transition and a carrier transition, according to an example embodiment.

[0041] Figure 3 A provides a schematic diagram of providing the first and second manipulation signals to the cooling area, according to an example embodiment.

[0042] Figure 3B provides a schematic diagram of providing the first and second manipulation signals to the cooling area, according to another example embodiment.

[0043] Figures 4A and 4B provide block diagrams schematically illustrating portions of respective confinement apparatuses and at least a portion of the respective beam path systems, according to an example embodiment.

[0044] Figure 5 schematically illustrates some example cross-sectional intensity profiles of some optical modes, according to various embodiments.

[0045] Figures 6A and 6B each provide a respective block diagram schematically illustrating a portion of a confinement apparatus and at least a portion of the one or more beam path systems, according to another example embodiment.

[0046] Figure 7 provides a flowchart illustrating various processes and / or procedures performed by a controller of Figure 8, for example, to cause an atomic system and / or quantum computer to perform a cooling operation, in accordance with an example embodiment.

[0047] Figure 8 provides a schematic diagram of an example controller of a quantum computer comprising a confinement apparatus configured for confining quantum objects therein, in accordance with an example embodiment.

[0048] Figure 9 provides a schematic diagram of an example computing entity of a quantum computer system that may be used in accordance with an example embodiment.DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

[0049] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The term “or” (also denoted “ / ”) is used herein in both the alternative and conjunctive sense, unless otherwise indicated. The terms “illustrative” and “exemplary” are used to be examples with no indication of quality level. The terms “substantially,” “generally,” and “approximately” refer to within appropriate engineering and / or manufacturing tolerances and / or within user measurement capabilities, unless otherwise indicated. Like numbers refer to like elements throughout.

[0050] In various scenarios, laser cooling is used to cool quantum and / or atomic object confined by a confinement apparatus. For example, a quantum charge-coupled device (QCCD)-based quantum computer may comprise a confinement apparatus that confines one or more object crystals. Each object crystal includes at least one qubit object and at least one coolant object that are confined within the same potential well. The qubit object(s) and the coolant object(s) are of different object species. For example, the qubit object(s) and the coolant object(s) may be neutral atoms or ions of different atomic species (e.g., different atomic numbers). The qubit object may be cooled (e.g., in preparation for performing a quantum logic gate on the qubit object or other quantum operation configured to cause a controlled evolution of the quantum state of the qubit object) using sympathetic laser cooling.

[0051] Laser cooling includes causing one or more laser beams to be incident on a coolant object that cause the coolant object to undergo a transition that results in a reduction in the phonon population of a motional mode of the object crystal. For example, as shown in Figure 2B, the coolant object may be caused to undergo a sideband transition 252 from state |a, n>, where |a> is an internal quantum state of the coolant object and n is a phonon population of the object crystal, to a state |b, n-l>, where |b> is a different internal quantum state of the coolant object and that may be of higher energy than state |a>. Thus, the phonon population of the object crystal is reduced by the coolant object undergoing the sideband transition 252. The quantum state of the coolant object decays from state |b> to state |a> and the process may be repeated to further cool (i.e., reduce the phonon population of) the object crystal.

[0052] However, the one or more laser beam used to drive the sideband transition 252 may also off-resonantly drive a carrier transition 254 such that the object crystal transitions from state |a, n> to state |b, n>. In other words, the carrier transition 254 results in the transition from state |a> to state |b>, but does not cool (i.e., reduce the phonon population of) theobject crystal. The one or more laser beams used to drive the sideband transition couple more strongly to the carrier transition than to the cooling sideband transition. For example, the one or more laser beams may be ten to twenty more times more likely to drive the carrier transition than the sideband transition. This results in cooling operations that can take a significant amount of time to perform. Therefore, technical problems exist regarding how to efficiently and / or quickly cool an object crystal.

[0053] Various embodiments provide technical solutions to these technical challenges. In various embodiments, an object crystal is confined by a confinement apparatus such that the coolant object is located at a target location defined at least in part by the confinement apparatus. A first manipulation signal and a second manipulation signal are caused to be incident on the object crystal and / or the coolant object. The first manipulation signal is red detuned from a first transition between a first quantum state of the coolant object and an excited state of the coolant object and the second manipulation is red detuned from a second transition between a second quantum state of the coolant object and the excited state of the coolant object. When the first manipulation signal and the second manipulation signal are applied to the coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal. In an example embodiment, the red effective detuning is substantially equal to the motional mode frequency or a multiple thereof. For example, the first manipulation signal and the second manipulation signal are configured to cause the coolant object to experience a two-photon red sideband transition 252 (without driving the carrier transition 254).

[0054] The first manipulation signal is provided to the cooling area as a spatially structured optical field. For example, the spatially structured optical field includes one or more spatially stable intensity minima or nulls. In other words, the intensity of the spatially structured optical field is approximately zero at one or more locations within the cooling area. In various embodiments, the intensity minima or nulls (or at least one of the intensity minima or nulls) of the spatially structured optical field is located at, disposed at, and / or coincides with the target location. The coolant object is confined such that the coolant object is located at the target location (e.g., at an intensity minimum and / or null of the spatially structured optical field).

[0055] The gradient of the amplitude / magnitude of the spatially structured optical field isnon-zero at the intensity minima and / or nulls of the spatially structured optical field such that the first manipulation signal and the second manipulation signal being incident on the cooling object causes the coolant object to undergo the red sideband transition 252, but to not undergo the carrier transition 254. For example, the coupling rate of the carrier transition is decreased to approximately zero.

[0056] The decreased coupling rate of the carrier transition 254 results in the cooling of the object crystal being significantly more effective and / or time-efficient. In particular, the time required to cool an object crystal can be reduced by a factor of 10 to 100 by reducing the coupling rate of the carrier transition 254 to approximately zero. For example, a conventional cooling operation may take 10 to 100 times longer to perform than a cooling operation of an example embodiment that provides the first manipulation signal to the object crystal as a spatially structured optical field.

[0057] By decreasing cooling operation times by a factor of 10 to 100, various embodiments provide technical improvements to fields that use laser cooling to cool quantum and / or atomic objects. For example, various embodiments provide technical improvements to atomic and / or quantum systems, such as QCCD-based quantum computers, for example, that use laser cooling (e.g., sympathetic laser cooling) to cool quantum and / or atomic objects used for performance of experiments and / or storing of quantum information (e.g., used as qubits).Example Quantum Computer System

[0058] Various embodiments provide quantum and / or atomic systems, such as quantum computers (e.g., QCCD-based quantum computers) that use quantum and / or atomic objects for storing quantum information, performing quantum computations, performing experiments, and / or the like. For example, a qubit object of the object crystal may be used for storing quantum information, performing quantum computations, performing experiments, and / or the like. A coolant object of the object crystal may be used to cool (e.g., via sympathetic laser cooling) the qubit object of the object crystal.

[0059] Figure 1 provides a schematic diagram of an example quantum computer system 100 configured to perform cooling operations using a spatially structured optical field, in accordance with various embodiments. In the illustrated embodiment, the quantum computer system 100 includes a confinement apparatus 120 (e.g., an ion trap) configured to confine a plurality of object crystals and each including at least one qubit object and at least onecoolant object. In various embodiments, the qubit objects are used as qubits of the quantum computer 110.

[0060] In various embodiments, the quantum computer system 100 comprises a classical (e.g., semiconductor-based) computing entity 25 and a quantum computer 110. In various embodiments, the quantum computer 110 comprises a controller 30, a cryostat and / or vacuum chamber 40 enclosing a confinement apparatus 120, one or more manipulation sources 64 (e.g., 64A, 64B, 64C, 64D, 64E), one or more voltage sources 50, an optics collection system 80, one or more sensors (e.g., calibration sensors and / or the like) and / or the like. In various embodiments, the controller 30 is configured to control the operation of (e.g., control one or more drivers configured to cause operation of) the manipulation sources 64, voltage sources 50, a vacuum system and / or cryogenic cooling system (not shown), and / or the like. In various embodiments, the controller 30 is configured to receive sensor signals (e.g., electrical signals) generated and provided by one or more photodetectors of the optics collection system 80 and / or other sensors of the system.

[0061] In an example embodiment, a second substrate 122 may be secured into relationship with the confinement apparatus 120 and house one or more components of the system (e.g., one or more manipulation sources 64E, one or more optical components of a beam path system 66 (e.g., 66A, 66B, 66C), one or more components of the optics collection system 80, one or more sensors, and / or the like).

[0062] In an example embodiment, the one or more manipulation sources 64 may comprise one or more lasers (e.g., optical lasers, microwave sources and / or masers, and / or the like) or another manipulation source. In the illustrated embodiment, manipulation sources 64A, 64B, 64C are lasers located outside of the cryogenic and / or vacuum chamber. Manipulation source 64D is a laser, microwave source, or magnetic field or magnetic field gradient source (e.g., permanent magnets, Helmholtz coils, electrical magnets, integrated circuits, and / or the like) that is integrated with the confinement apparatus 120. In an example embodiment, a manipulation source 64E is a laser, microwave source, or magnetic field or magnetic field gradient source (e.g., permanent magnets, Helmholtz coils, electrical magnets, integrated circuits, and / or the like) that is integrated with the second substrate 122.

[0063] In various embodiments, the one or more manipulation sources 64 are configured to manipulate and / or cause a controlled quantum state evolution of one or more qubit objects confined by the confinement apparatus 120. In various embodiments, one or more manipulation sources 64 are configured to generate and / or provide one or more manipulation signals configured for performing laser cooling, quantum object initialization and / or statepreparation, shelving operations, single qubit gates, two-qubit gates, fluorescence measurement operations, and / or other operations on the quantum objects confined by the confinement apparatus 120. For example, in various embodiments, the manipulation sources 64 include one or more manipulation sources configured to generate and / or provide a first manipulation signal and / or a second manipulation signal to one or more cooling areas defined at least in part by the confinement apparatus.

[0064] In various embodiments, the confinement apparatus 120 is an ion trap, such as a surface ion trap, Paul ion trap, and / or the like. In various embodiments, the quantum and / or objects are ions, atoms, molecules, quantum particles, and / or the like. For example, the qubit objects and the coolant objects may be ions of different atomic species.

[0065] In an example embodiment, the one or more manipulation sources 64A, 64B, 64C (located outside of the cryogenic and / or vacuum chamber 40) each provide a manipulation signal (e.g., laser beam, microwave signals, and / or the like) to one or more areas, regions, and / or target locations 125 of the confinement apparatus 120 via corresponding beam path systems 66 (e.g., 66A, 66B, 66C). In various embodiments, at least one beam path system 66 comprises a modulator configured to modulate the manipulation signal being provided to the confinement apparatus 120 via the beam path system 66. In various embodiments, the manipulation sources 64, active components of the beam path systems 66 (e.g., modulators, etc.), and / or other components of the quantum computer 110 are controlled by the controller 30. In various embodiments, at least one of the beam path systems 66 includes components configured to provide a first manipulation signal to a cooling area as a spatially structured optical field having one or more intensity minima and / or nulls at one or more target locations 125 within the cooling area.

[0066] In various embodiments, the quantum computer 110 comprises one or more voltage sources 50. For example, the voltage sources may be arbitrary wave generators (AWG), digital analog converters (DACs), and / or other voltage signal generators. For example, the voltage sources 50 may comprise a plurality of control voltage drivers and / or voltage sources and / or at least one RF driver and / or voltage source. The voltage sources 50 may be electrically coupled to the corresponding potential generating elements (e.g., control electrodes and / or RF electrodes) of the confinement apparatus 120, in an example embodiment. For example, the controller 30 may control operation of the one or more voltage sources 50 to cause the confinement apparatus 120 to confine an object crystal within a cooling area and confine a coolant object at a target location 125 within the cooling area for performance of a cooling operation thereon. For example, in some embodiments, thecontroller 30 controls operation of the confinement apparatus 120 by controlling operation of the voltage sources 50 configured to provide respective voltage signals to respective electrodes, for example, of the confinement apparatus 120.

[0067] In various embodiments, the quantum computer 110 comprises an optics collection system 80 configured to collect and / or detect photons (e.g., stimulated emission) generated by quantum objects (e.g., during reading procedures). The optics collection system 80 may comprise one or more optical elements (e.g., lenses, mirrors, waveguides, fiber optics cables, and / or the like) and one or more sensors, such as photodetectors. In various embodiments, the photodetectors may be photodiodes, photomultipliers, charge-coupled device (CCD) sensors, complementary metal oxide semiconductor (CMOS) sensors, Micro-Electro-Mechanical Systems (MEMS) sensors, and / or other photodetectors that are sensitive to light at an expected fluorescence wavelength of the qubits (e.g., quantum objects) of the quantum computer 110. In various embodiments, the sensors (e.g., photodetectors) are in electronic communication with the controller 30 via one or more A / D converters 825 (see Figure 8) and / or the like.

[0068] In various embodiments, the quantum computer may include various other sensors configured for measuring voltage, current, optical power, magnetic fields, and / or the like at various locations within the quantum computer. The sensors may be used to perform image current detection, calibration of voltage signals or manipulation signals, and / or the like.

[0069] In various embodiments, a computing entity 25 is configured to allow a user to provide input to the quantum computer 110 (e.g., via a user interface of the computing entity 25) and receive, view, and / or the like output from the quantum computer 110. The computing entity 25 may be in communication with the controller 30 of the quantum computer 110 via one or more wired or wireless networks 20 and / or via direct wired and / or wireless communications. In an example embodiment, the computing entity 25 may translate, configure, format, and / or the like information / data, quantum computing algorithms (e.g., quantum circuits), and / or the like into a computing language, executable instructions, command sets, and / or the like that the controller 30 can understand, execute, and / or implement.

[0070] In various embodiments, the controller 30 is configured to control operation of the voltage sources 50, cryogenic system and / or vacuum system controlling the temperature and pressure within the cryogenic and / or vacuum chamber 40, manipulation sources 64, beam path systems 66, and / or other systems controlling various environmental conditions (e.g., temperature, pressure, and / or the like) within the cryogenic and / or vacuum chamber 40,configured to manipulate and / or cause a controlled evolution of quantum states of one or more quantum objects within the confinement apparatus, and / or read and / or detect a quantum (e.g., qubit) state of one or more qubit objects confined by the confinement apparatus. In various embodiments, the controller 30 controls operation of the confinement apparatus 120 via controlling operation of the one or more voltage sources 50 to cause desired sequences of voltage signals to be applied to electrodes of the confinement apparatus 120. For example, the controller 30 may cause a controlled evolution of quantum states of one or more qubit objects within the confinement apparatus to execute a quantum circuit and / or algorithm. For example, the controller 30 may control various components of the quantum computer 110 to cause the quantum computer 110 to perform cooling operations, in accordance with example embodiments, on one or more object crystals confined by the confinement apparatus at one or more points during the execution of a quantum circuit, in preparation for performance of a quantum circuit, and / or the like.Example Cooling Operations using Spatially Structured Optical Fields

[0071] Various embodiments provide methods for performing a cooling operation using a spatially structured optical field and quantum computers, quantum and / or atomic systems, controllers, and / or apparatus configured and / or programmed to implement an example embodiment of a cooling operation using a spatially structured optical field.

[0072] Figure 2A provides a partial internal energy diagram 200 of an example coolant object. The coolant object includes a first quantum state |a>, a second quantum state |b>, and an excited state |e>. In some embodiments, the first quantum state |a> and the second quantum state |b> are in a ground manifold of the coolant object and the excited state |e> is not in the ground manifold of the coolant object.

[0073] A first manipulation signal 202 is configured to couple the first quantum state |a> to the excited state |e> and is detuned from the transition between the first quantum state |a> and the excited state |e> by a first detuning Ai. In some embodiments, the first manipulation signal 202 is a laser beam that is characterized by a first frequency coi that corresponds to the transition between the first quantum state |a> and the excited state |e>. For example, the first frequency coi is detuned from a characteristic frequency of the transition between the first quantum state |a> and the excited state |e> by a first detuning Ai. The first manipulation signal 202 couples the first quantum state |a> to the excited state |e> with a first coupling rate Hi. In some embodiments, the first frequency coi is in the visiblespectrum.

[0074] A second manipulation signal 204 is configured to couple the second quantum state |b> to the excited state |e> and is detuned from the transition between the second quantum state |b> and the excited state |e> by a second detuning 2. In some embodiments, the second manipulation signal 204 is a laser beam that is characterized by a second frequency C02 that corresponds to the transition between the second quantum state |b> and the excited state |e>. For example, the second frequency 0)2 is detuned from a characteristic frequency of the transition between the second quantum state |b> and the excited state |e> by a second detuning 2. The second manipulation signal 204 couples the second quantum state |b> to the excited state |e> with a second coupling rate (12. In some embodiments, the second frequency 0)2 is in the visible spectrum.

[0075] In various embodiments, the first manipulation signal 202 and the second manipulation signal 204 are configured to perform laser cooling of at least one motional mode of the object crystal on a dipole Raman transition of the coolant object.

[0076] The first quantum state |a> and the second quantum state |b> are stable over the cooling timescale (e.g., stable over the time required for performing a cooling operation). The excite state |e> relaxes and / or decays to first quantum state |a> and / or the second quantum state |b> with a combined rate T. In various embodiments, the first coupling rate (li, the second coupling rate (1.2, the first detuning Ai, and the second detuning 2 are selected such that the excited state |e> is negligibly populated and therefore can be adiabatically eliminated, yielding an effective two-level system in the ground manifold of the coolant object, as illustrated in Figure 2B. For example, the coolant object may undergo a virtual transition (from the first quantum state |a> to the second quantum state |b>) mediated by the excited state |e> via the first manipulation signal 202 and the second manipulation signal 204.

[0077] Figure 2B illustrates a partial energy diagram 250 of a coolant object where the energy states illustrated are combination internal quantum states and motional states of the coolant object. As shown in Figure 2B, the coolant object may be caused to undergo a (red) sideband transition 252 from state |a, n>, where |a> is the first (internal) quantum state of the coolant object and n is a phonon population of the object crystal, to a state |b, n-l>, where |b> is the second (internal) quantum state of the coolant object that is of higher energy than the first (internal) quantum state |a>. In some embodiments, sideband transition 252 may be transition from state |a, n> to state |b, n-p>, where p is a positive integer that isless than or equal to n.

[0078] As n - 1 (or n-p) is less than n, the phonon population of the object crystal is reduced by the coolant object undergoing the (red) sideband transition 252. The quantum state of the coolant object decays and / or is repumped from state |b, n-l> to state |a, n-l> and the process may be repeated to further cool (i.e., reduce the phonon population of) the object crystal. For example, the first manipulation signal and the second manipulation being incident on the coolant object may cause the quantum state of the coolant object to transition from state |a, n-l> to state |b, n-2>. This process may be repeated to eventually yield a quantum state primarily consisting of |a, 0>, thereby preparing the mode near to its motional ground state.

[0079] Thus, in various embodiments, a cooling operation includes preparing the coolant object in one of the first quantum state |a> or the second quantum state |b> and performing a plurality of cooling cycles. A cooling cycle includes applying the first manipulation signal 202 and the second manipulation signal 204 to the coolant object and / or the object crystal such that the (red) sideband transition 252 is driven. A repump laser may be used in some embodiments to drive the system from the second quantum state |b> to the excited quantum state |e> either continuously or stroboscopically (i.e., pulsed) until spontaneous emission relaxes the quantum state of the coolant object back to the first quantum state |a>. For example, a cooling cycle may further include repumping the quantum state of the coolant object to the excited quantum state |e> until the quantum state of the coolant object decays to the first quantum state |a>. In instances where the repump process imparts less motional energy (on average) than is removed by the (red) sideband transition 252, the coolant object and / or object crystal may be cooled near to the motional ground state of the object crystal with a sufficient number of cooling cycles.

[0080] The first manipulation signal 202 and the second manipulation signal 204 may, off- resonantly, drive a carrier transition 254 from state |a, n> to state |b, n>. In various embodiments, the (red) sideband transition 252 is (red) detuned from a carrier transition 254 by an effective detuning 6. In various embodiments, the effective detuning 6 is a frequency that corresponds to at least one motional mode frequency corresponding to a motional mode of the object crystal. For example, the (red) sideband transition 252 is configured to reduce the phonon population of one or more motional modes corresponding to respective motional mode frequencies that correspond to the effective detuning 6.

[0081] In various embodiments, an object crystal that consists of q quantum and / or atomic objects (including at least one qubit object and at least one coolant object) has 3q motionalmodes. Each motional mode corresponds to movement along a respective principle motional mode axis with a respective motional mode frequency.

[0082] In various embodiments, the first manipulation signal 202 and second manipulation signal 204 are configured to cool (e.g., reduce the phonon population of) a particular motional mode. For example, in certain embodiments, the first manipulation signal 202 and / or the second manipulation signal 204 are configured to form a spatially structured optical field that, at a target location, has a non-zero amplitude / magnitude gradient projection onto a first motional mode axis corresponding to a first motional mode of the 3q motional modes of the object crystal (consisting of q quantum and / or atomic objects) and an effective detuning of the first manipulation signal 202 and the second manipulation signal from the carrier transition 254 from state |a, n> to state |b, n> corresponds to at least one first motional mode frequency corresponding to the first motional mode.

[0083] In various embodiments, the first manipulation signal 202 and second manipulation signal 204 are configured to cool (e.g., reduce the phonon population of) two or more motional modes. For example, in certain embodiments, the first manipulation signal 202 and / or the second manipulation signal 204 are configured to form a spatially structured optical field that, at a target location, has a non-zero amplitude / magnitude gradient projection onto a first motional mode axis corresponding to a first motional mode of the 3q motional modes of the object crystal and a non-zero amplitude / magnitude gradient projection onto a second motional mode axis corresponding to a second motional mode of the 3q motional modes of the object crystal. The first motional mode corresponds to a first motional mode frequency and the second motional mode corresponds to a second motional mode frequency. In some instances, the first motional mode frequency and the second motional mode frequency are similar such that the effective detuning of the first manipulation signal 202 and the second manipulation signal 204 from the carrier transition 254 from state |a, n> to state |b, n> may be selected such that both the first motional mode and the second motional mode are effectively cooled. In some instances, the effective detuning of the first manipulation signal 202 and the second manipulation signal from the carrier transition 254 from state |a, n> to state |b, n> may be selected to be an intermediate frequency between the first motional mode frequency and the second motional mode frequency such that both the first motional mode and the second motional mode are effectively cooled.

[0084] Generally, as the carrier transition 254 does not result in the phonon population of the object crystal being reduced, the carrier transition is undesired. In various embodiments,the first manipulation signal 202 and the second manipulation signal 204 are provided to the cooling area in which the object crystal to be cooled is confined such that the coupling rate flc of the carrier transition 254 is approximately zero. In various embodiments, the coupling rate flc of the carrier transition 254 being approximately zero is achieved by at least one of the first manipulation signal or the second manipulation signal are provided to the cooling area as a spatially structured optical field.

[0085] A spatially structured optical field is an optical field having one or more spatially stable optical intensity minima and / or nulls (e.g., places in space where the absolute value of the amplitude of a manipulation signal is at a minimum and / or approximately equal to zero). A spatially structured optical field may also have spatially stable optical intensity maxima (e.g., locations where the absolute value of the amplitude of the manipulation signal is at a maximum). In general, an effective intensity minimum is a portion of the spatially structured optical field having low intensity (e.g., an intensity within 15% of the local intensity minimum) and a high gradient (e.g., a gradient magnitude within 20% of the local gradient maximum). In various embodiments, the optical intensity of a local intensity minimum is approximately zero. For example, an intensity minimum is a null in the electrical field of a spatially structured optical field. The respective locations of one or more intensity minima of a spatially structured optical field within a cooling area do not evolve with time during the time period (e.g., the cooling time) that the optical field is being provided.

[0086] In various embodiments, the spatially structured optical field is configured such that each target location 125 is located at one of the effective intensity minima of the spatially structured optical field. For example, in various embodiments, a spatially structured optical field is configured to have (approximately) zero electric field and a non-zero electric field amplitude / magnitude gradient at the target location 125 within the cooling area. In some embodiments, the spatial dependence of a spatially structured optical field corresponds to that of a standing wave, Hermite-Gaussian mode, Laguerre- Gaussian mode, or other Gaussian mode profile. In other embodiments, the spatial field dependence is chosen or engineered to provide the desired one or more intensity minima and amplitude / magnitude gradient at the target location 125.

[0087] In Figures 3 A, 3B, 4A, 4B, 6A, and 6B the first manipulation signal is provided to the cooling area as a spatially structured optical field having one or more intensity minima or nulls (e.g., at respective target locations) and the second manipulation signal is provided as an optical field that is not spatially structured (e.g., as a 00 Gaussian modetravelling wave). For example, this may minimize any resulting heating due to spontaneous emission caused by the first manipulation signal interacting with the coolant object. In some embodiments, the second manipulation signal is provided to the cooling area as a spatially structured optical field having one or more intensity minims or nulls (e.g., a respective target locations) and the first manipulation signal is provided as an optical field that is not spatially structured (e.g., as a 00 Gaussian mode travelling wave). In an example embodiment, one of the first manipulation signal or the second manipulation signal is provided to the cooling area as a spatially structured optical field having one or more effective intensity minima at respective target locations and the other of the first manipulation signal or the second manipulation signal is provided to the cooling area as a spatially structured optical field that does not have effective intensity minima at the target locations (e.g., could have an intensity maximum at the target location and / or the like). In an example embodiment, both the first manipulation signal and the second manipulation signal are provided to the cooling area as spatially structured optical fields having effective intensity minima at the target location(s).

[0088] In Figures 3 A, 3B, 4A, 4B, 6A, and 6B, the motional mode being cooled is an axial motional mode. For example, the principle motional mode axis of the motional mode being cooled is aligned with the object axis of the object crystal. In some embodiments, the object axis is aligned with a radiofrequency null defined by the confinement apparatus at the location of the object crystal. In various embodiments, the motional mode being cooled may be an axial motional mode (having a principle motional mode axis that is aligned with the object axis) or a radial motional mode (having a principle motional mode axis that is perpendicular to the object axis).

[0089] Figure 3A schematically illustrates a scenario 300 where the first manipulation signal 302 is provided to the cooling area 306 as a standing wave. An object crystal 15 including a qubit object 5 and a coolant object 10 are confined, by the confinement apparatus 120, in a cooling area 306 such that the coolant object 10 is located at the target location 125. The motional mode being cooled in scenario 300 is an axial motional mode such that the principle motional mode axis is aligned with the axis 308 of the object crystal 15.

[0090] A first portion of the first manipulation signal 302 A and the second manipulation signal 304 are provided from a first side of the cooling area 306 and propagate across the cooling area 306 in a first direction. A second portion of the first manipulation signal 302B is provided from a second side of the cooling area 306. The second side of thecooling area is opposite the first side of the cooling area, in the illustrated embodiment. The second portion of the first manipulation signal 302B propagates across the cooling area 306 in a second direction. In the illustrated embodiment, the first portion of the first manipulation signal 302 A and the second portion of the first manipulation signal 302B interact with one another within the cooling area 306 to generate a spatially structured optical field in the form of a standing wave. In various embodiments, the first direction and the second direction are configured such that a difference wave vector of the first portion of the first manipulation signal 302 A and the second portion of the first manipulation signal 302B has a non-zero projection along the motional mode axis 308 of the motional mode being cooled, at the target location 125.

[0091] The second manipulation signal 304 is also provided such that the second manipulation signal 304 propagates across the cooling area 306. The direction of propagation of the second manipulation signal 304 across the cooling area 306 (e.g., with respect to the motional mode axis 308 corresponding to the motional mode being cooled) may vary in various embodiments.

[0092] Plot 310 illustrates the spatial dependence of the coupling rate of the first manipulation signal 312 and the spatial dependence of the coupling rate of the second manipulation signal 314 as a function of the position across (e.g., in the x-direction as illustrated in Figure 3A) the cooling area 306. The spatial dependence of the coupling rate of the second manipulation signal 314 is substantially constant across the cooling area 306. The spatial dependence of the coupling rate of the first manipulation signal 312 is not constant across the cooling area 306. Rather, the spatial dependence of the coupling rate of the first manipulation signal 312 is periodic as a result of the first manipulation signal 302 being provided to the cooling area as a spatially structured optical field, in the form of a standing wave. The coolant object 10 is located at a null in the spatial dependence of the coupling rate of the first manipulation signal 312. As the square of the coupling rate of the first manipulation signal at any location is proportional to the intensity of the first manipulation signal at that location, the coolant object 10 is located at a null or local minimum in the intensity of the spatially structured optical field of the first manipulation signal. As a result of the coolant object being located at a null in the spatial dependence of the coupling rate of the first manipulation signal 362, the carrier transition 254 is suppressed (e.g., the probability of the carrier transition 254 occurring is approximately zero).

[0093] Figures 4A illustrates a partial top view of an example configuration of aconfinement apparatus 120 configured for providing the first manipulation signal to a cooling area as a spatially structured optical field in the form of a standing wave. An object crystal 15 including a qubit object 5 and a coolant object 10 are confined, by the confinement apparatus 120, in a cooling area 406 such that the coolant object 10 is located at the target location 125. The motional mode being cooled in the configurations illustrated in Figures 4A and 4B is an axial motional mode such that the principle motional mode axis 408 is aligned with the axis of the object crystal 15.

[0094] As shown in Figure 4A, one or more beam path systems 66 include one or more components that are housed by the same substrate that houses the confinement apparatus 120. For example, a first source beam path 420 is configured to direct and / or guide the first manipulation signal 402 from a first manipulation source 64 that generated the first manipulation signal to a beam splitter 422. For example, the first source beam path 420 may comprise one or more waveguides, optical fibers, free space optical elements, and / or various couplers configured to guide the first manipulation signal from a manipulation source 64 that generated the first manipulation signal to the beam splitter 422.

[0095] The beam splitter 422 splits the first manipulation signal 402 into a first portion of the first manipulation signal 402A and a second portion of the first manipulation signal 402B. The beam splitter 422 provides the first portion of the first manipulation signal 402A to a first beam path 424A configured to guide the first portion of the first manipulation signal 402A to a first component 442A. The beam splitter provides the second portion of the first manipulation signal 402B to a second beam path 424B configured to guide the second portion of the first manipulation signal 402B to a second component 442B.

[0096] The first component 442A and the second component 442B are configured to cause the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B, respectively, to propagate across the cooling area 406. For example, the first component 442A and the second component 442B may comprise grating couplers, metasurfaces, lenses, and / or other optical components configured to couple the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B out of the first beam path 424A and the second beam path 424B, respectively, and cause the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B to propagate (e.g., through free space and / or vacuum) in respective directions such that a difference wave vector of the first portion of the first manipulation signal 402A and the second portion of the firstmanipulation signal 402B, at the target location, has a non-zero projection onto a motional mode axis 408 corresponding to a motional mode to be cooled. For example, in the illustrated embodiment, the first portion of the first manipulation signal 402A propagates through the cooling area 406 from left to right (e.g., the direction of propagation has a positive x-component), in the scenario illustrated in Figure 4A, and the second portion of the first manipulation signal 402B propagates through the cooling area 406 from right to left (e.g., the direction of propagation has a negative x-component), in the scenario illustrated in Figure 4A. The first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B interact within the cooling area to provide a spatially structured optical field within the cooling area 406 in the form of a standing wave.

[0097] At least one of the beam path systems 66 defines a second source beam path 430 configured to direct the second manipulation signal 404 from a second manipulation source 64 that generated the second manipulation signal 404 to a third component. In the illustrated scenario, third component is the same optical component as the first component 442A. However, in some embodiments, the third component is distinct and / or different from the first component 442A. In various embodiments, the third component may comprise a grating coupler, metasurface, lens, and / or other optical element configured to couple the second manipulation signal 404 out of the second source beam path 430 and direct the second manipulation signal 404 across the cooling area 406 in a direction has a non-zero projection onto the motional mode axis 408 corresponding to the motional mode to be cooled.

[0098] Figure 4B illustrates a partial cross-sectional view of an example configuration where the confinement apparatus 120 is housed by a first substrate 118. A second substrate 122 is secured with respect to the first substrate 118 via spacers 126 A, 126B. A first source beam path 420 is configured to direct and / or guide a first manipulation signal from a first manipulation source 64 to a beam splitter 422 that is housed by the second substrate 122. For example, the first source beam path 420 may comprise one or more waveguides, optical fibers, free space optical elements, and / or various couplers configured to guide the first manipulation signal from a manipulation source 64 that generated the first manipulation signal to the beam splitter 422.

[0099] The beam splitter 422 splits the first manipulation signal 402 into a first portion of the first manipulation signal 402A and a second portion of the first manipulation signal 402B. The beam splitter 422 provides the first portion of the first manipulation signal 402Ato a first beam path 424A that is configured to guide the first portion of the first manipulation signal 402A to a first component 442A. For example, the first beam path 424A comprises a waveguide that extends through a portion of the second substrate 122 and a first spacer 126 A. The first component 442 A is disposed on the first spacer 126 A. The beam splitter 422 provides the second portion of the first manipulation signal 402B to a second beam path 424B that is configured to guide the second portion of the first manipulation signal 402B to a second component 442B. For example, the second beam path 424B comprises a waveguide that extends through a portion of the second substrate 122 and a second spacer 126B. The second component 442B is disposed on the second spacer 126B.

[0100] The first component 442A and the second component 442B are configured to cause the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B, respectively, to propagate across the cooling area 406. For example, the first component 442A and the second component 442B may comprise grating couplers, metasurfaces, lenses, and / or other optical components configured to couple the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B out of the first beam path 424A and the second beam path 424B, respectively, and cause the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B to propagate (e.g., through free space and / or vacuum) in respective directions such that a difference wave vector between the first portion of the first manipulation signal 402A and the second portion of the first manipulation signal 402B has a non-zero projection onto the motional mode axis 408 corresponding to the motional mode to be cooled. For example, the first portion of the first manipulation signal 402A propagates through the cooling area 406 from left to right (e.g., the direction of propagation has a positive x-component), in the scenario illustrated in Figure 4B, and the second portion of the first manipulation signal 402B propagates through the cooling area 406 from right to left (e.g., the direction of propagation has a negative x-component), in the scenario illustrated in Figure 4B.

[0101] A plurality of cooling areas 406 (e.g., 406A, 406B, 406C) are defined by the confinement apparatus 120 between the first space 126A and the second spacer 126B. For example, the first portion of the first manipulation signal 402A and the second manipulation signal propagate across a plurality of cooling areas in the positive x- direction and the second portion of the first manipulation signal 402B propagates across the plurality of cooling areas in the negative x-direction. The first portion of the firstmanipulation signal 402A and the second portion of the first manipulation signal 402B interact within each of the cooling areas 406 to provide a spatially structured optical field within each cooling area 406 in the form of a standing wave. Cooling operations may therefore be performed in parallel in the plurality of cooling areas 406. In some embodiments, an object crystal includes more than one coolant object and each of the coolant objects of the object crystal may be confined at respective intensity nulls or minima within the cooling area 406.

[0102] At least one of the beam path systems 66 defines a second source beam path 430 configured to direct the second manipulation signal 404 from a second manipulation source 64 that generated the second manipulation signal 404 to a third component. For example, the second source beam path 430 may comprise one or more waveguides, optical fibers, free space optical elements, and / or various couplers configured to guide the second manipulation signal from a manipulation source 64 that generated the second manipulation signal to the third component. In the illustrated scenario, the third component is the same optical component as the first component 442A. However, in some embodiments, the third component is distinct and / or different from the first component 442A. In various embodiments, the third component may comprise a grating coupler, metasurface, lens, and / or other optical element configured to couple the second manipulation signal 404 out of the second source beam path 430 and direct the second manipulation signal 404 across the cooling area 406 in a direction that has a non-zero projection onto the motional mode axis 408 of the motional mode to be cooled.

[0103] Figure 3B illustrates an example scenario 350 where the first manipulation signal 352 is provided to the cooling area 306 as a spatially structured optical field in the form of a higher-order optical mode. Figure 5 schematically illustrates intensity profiles of beams of light in a direction perpendicular to the propagation direction for some example Hermite Gaussian optical modes. Generally, the transverse profiles of optical modes are parameterized by a pair of indices (n, m). For example, the 00 mode (e.g., a Gaussian beam) has a peak intensity (e.g., intensity maximum) at the middle of the beam and a radial intensity decay. Higher-order optical modes are optical modes where at least one of the pair of indices (n, m) is non-zero. These higher-order optical modes are characterized by intensity minima 502 within the intensity profile of the beam. As used herein, a higher-order optical mode is an optical mode that includes an intensity minima within the transverse intensity profile of the beam. In other words, a higher-order optical mode is an optical mode parameterized by indices (n, m), where at least one of m or n is an integergreater than zero. By aligning an intensity minimum 502 of a higher-order optical mode with the target location 125, the coolant object 10 may be made to experience a spatially structured optical field having (approximately) zero amplitude at the location of the coolant object 10. Hermite Gaussian optical modes are shown for illustrative purposes only. Various forms of optical modes (e.g., Hermite Gaussian, Laguerre-Gaussian, and / or the like) may be used in various embodiments.

[0104] Returning to Figure 3B, the object crystal 15, including the qubit object 5 and the coolant object 10 are confined within the cooling area 306 by the confinement apparatus 120 such that the coolant object is located at the target location 125. The first manipulation signal 352 is provided as a higher-order optical mode propagating in a direction that is not co-linear with or not aligned with the motional mode axis 308 corresponding to the motional mode to be cooled. Intensity minima of the higher-order optical mode are aligned with the target location(s) 125. The second manipulation signal 304 is provided such that the second manipulation signal 304 propagates across the cooling area 306. The direction of propagation of the second manipulation signal 304 across the cooling area 306 (e.g., with respect to the motional mode axis 308 corresponding to the motional mode being cooled) may vary in various embodiments.

[0105] Plot 360 illustrates the spatial dependence of the coupling rate of the first manipulation signal 362 and the spatial dependence of the coupling rate of the second manipulation signal 364 across (e.g., in the x-direction as illustrated in Figure 3B) the cooling area 306. The spatial dependence of the coupling rate of the second manipulation signal 364 is substantially constant across the cooling area 306. The spatial dependence of the coupling rate of the first manipulation signal 362 is not constant across the cooling area 306. Rather, the spatial dependence of the coupling rate of the first manipulation signal 362 includes a null at the target location 125 as a result of the first manipulation signal 352 being provided to the cooling area as a spatially structured optical field, in the form of a higher-order optical mode. The coolant object 10 is located at a null in the spatial dependence of the coupling rate of the first manipulation signal 362. As the square of the coupling rate of the first manipulation signal at any location is proportional to the intensity of the first manipulation signal at that location, the coolant object 10 is located at one of the nulls or local minima in the intensity of the spatially structured optical field of the first manipulation signal. As a result of the coolant object being located at a null in the spatial dependence of the coupling rate of the first manipulation signal 362, the carrier transition 254 is suppressed (e.g., the probability of the carrier transition 254 occurring isapproximately zero). Performance of the sideband transition 252 is dependent on the amplitude / magnitude gradient of the electric field at the target location, which is nonzero. Thus, the sideband transition 252 is still driven.

[0106] Figure 6A illustrates a partial cross-sectional view of an example confinement apparatus 120. An object crystal including a qubit object 5 and a coolant object 10 are confined, by the confinement apparatus 120, in a cooling area such that the coolant object is located at a target location 125. In the illustrated embodiment, an axial motional mode is being cooled meaning that the motional mode axis 608 is substantially parallel to the axis of the object crystal (e.g., the axis along which the quantum objects of the object crystal are aligned). The second manipulation signal 604 is provided to the cooling area such that the second manipulation signal propagates across the cooling area and interacts with the coolant object located at the target location 125.

[0107] The confinement apparatus is housed by a first substrate 118. The first substrate 118 also houses at least a portion of a first source beam path 620 that is defined by and / or part of a beam path system 66. The first source beam path 620 is configured to provide the first manipulation signal to a component 642A housed by the first substrate 118. For example, the first source beam path 620 may comprise one or more waveguides, optical fibers, free space optical elements, and / or various couplers configured to guide the first manipulation signal from a manipulation source 64 that generated the first manipulation signal to the component 642A.

[0108] The component 642A comprises a grating coupler, metasurface, lens, and / or other optical components configured to cause the first manipulation signal to be coupled out of the first source beam path 620 such that the first manipulation signal 602A propagates away from a surface of the confinement apparatus 120 in a direction that is not parallel to the surface of the confinement apparatus 120 and that is not co-linear or aligned with the motional mode axis 608 of the motional mode to be cooled.

[0109] In some embodiments, the first manipulation signal is provided to the first source beam path 620 in a desired higher-order optical mode. In some embodiments, the first manipulation signal is provided to the first source beam path 620 as a Gaussian mode or 00 mode and the component 642 A is configured to modify, adjust, and / or control the optical mode of the first manipulation signal such that the first manipulation signal 602A is provided to the cooling area as the desired higher-order optical mode. Moreover, the component 642A is configured to provide the first manipulation signal 602A to the cooling area such that one or more intensity minima of the higher-order optical mode arealigned with the target location(s) 125.

[0110] Figure 6B illustrates a partial cross-sectional view of another confinement apparatus 120 where a second substrate 122 is secured with respect to the confinement apparatus 120. The second substrate houses at least a portion of a first source beam path 620 and a component 642B. The first source beam path 620 is configured to provide the first manipulation signal to the component 642B. For example, the first source beam path 620 may comprise one or more waveguides, optical fibers, free space optical elements, and / or various couplers configured to guide the first manipulation signal from a manipulation source 64 that generated the first manipulation signal to the component 642B.[OHl] The component 642B comprises a grating coupler, metasurface, lens, and / or other optical components configured to cause the first manipulation signal to be coupled out of the first source beam path 620 such that the first manipulation signal 602B propagates away from a surface of the second substrate 122 (e.g., in a direction that is not parallel to the surface of the confinement apparatus 120) in a direction that is not co-linear or not aligned with the motional mode axis 608.

[0112] In some embodiments, the first manipulation signal is provided to the first source beam path 620 in a desired higher-order optical mode. In some embodiments, the first manipulation signal is provided to the first source beam path 620 as a Gaussian mode or 00 mode and the component 642B is configured to modify, adjust, and / or control the optical mode of the first manipulation signal such that the first manipulation signal 602B is provided to the cooling area as the desired higher-order optical mode. Moreover, the component 642B is configured to provide the first manipulation signal 602B to the cooling area such that one or more intensity minima of the higher-order optical mode are aligned with the target location(s) 125.

[0113] Figure 7 provides a flowchart illustrating various processes and / or procedures performed by a controller 30 of a quantum and / or atomic system, such as QCCD-based quantum computer 110, for example, to cause the quantum and / or atomic system to perform a cooling operation using a spatially structured optical field, in accordance with an example embodiment.

[0114] Starting at step 702, the controller 30 controls operation of the confinement apparatus 120 to cause a selected object crystal to be confined at the cooling area with the coolant object located at the target location 125. For example, the controller 30 may control operation of one or more voltage sources 50 such that the one or more voltagesources 50 generate voltage signals which are applied to respective electrodes of the confinement apparatus 120 to cause the confinement apparatus to generate a trapping pseudopotential configured to confine one or more object crystals. Each object crystal includes at least one qubit object and at least one coolant object. Qubit objects are quantum and / or atomic objects of a first species and coolant objects are quantum and / or atomic objects of a second species that is different from the first species. For example, the qubit objects may be ions of a first atomic species and the coolant objects may be ions of a different atomic species.

[0115] The controller 30 controls operation of the one or more voltage sources 50 to cause the one or more voltage sources 50 to generate voltage signals, which are applied to respective electrodes of the confinement apparatus 120, to generate a pseudopotential that causes the selected object crystal to be transported to and / or maintained at the cooling area such that the coolant object is located at the target location 125. For example, as shown in Figure 8, the controller 30 may comprise means, such as processing device 805, memory 810, driver controller elements 815, and / or the like, for controlling operation of the confinement apparatus 120 to cause a selected object crystal to be confined at the cooling area such that the coolant object is located at the target location 125.

[0116] In various embodiments, the controller 30 may be preparing to perform a quantum operation, such as a state preparation operation, single qubit gate, two-qubit gate, reading operation, or other operation on the at least one qubit object of the selected object crystal. For example, the controller 30 may store (e.g., in memory 810) a queue of instructions to be executed to cause the quantum processor 115 to perform a quantum computation. The queue of instructions may include instructions configured to cause the quantum processor 115 to perform various operations (e.g., state preparation operations, single qubit gats, two-qubit gates, reading operations, and / or the like) on one or more qubit objects of respective object crystals. In various embodiments, the controller 30 is configured to, prior to performance of the state preparation operation, single qubit gate, two-qubit gate, reading operation, or other operation of the at least one qubit object of an object crystal, perform a cooling operation on the object crystal. In some embodiments, the operation (e.g., state preparation operation, single qubit gate, two-qubit gate, reading operation, or other operation) is performed on the at least one qubit object of the object crystal while the object crystal is confined at the cooling area. For example, the cooling area may also be a gating area, reading / measurement area, state preparation area, and / or the like. In other embodiments, the selected object crystal is confined at the cooling area and acooling operation is performed thereon during the transportation of the object crystal to a gating area, reading / measurement area, state preparation area, and / or the like.

[0117] At step 704 of Figure 7, the controller 30 controls operation of one or more manipulation sources 64 and, possibly, beam path systems 66 to cause a first manipulation signal and a second manipulation signal to begin to be provided to the cooling area. One of the first manipulation signal or the second manipulation signal is provided to the cooling area as a spatially structured optical field (e.g., as a standing wave or as a higher-order optical mode) with one or more effective intensity minima at respective target locations 125. For example, the controller 30 comprises means, such as processing device 805, memory 810, driver controller elements 815, and / or the like, for controlling operation of one or more manipulation sources 64 and, possibly, one or more beam path systems 66 to cause the first manipulation signal and the second manipulation signal to be provided to the cooling area.

[0118] For example, in one embodiment, the controller 30 controls operation of a first laser to cause the first manipulation signal (e.g., a first laser beam) to be generated and provided to a first beam path system 66 configured to provide the first manipulation signal to the cooling area. The controller 30 also controls operation of a second laser to cause the second manipulation signal (e.g., a second laser beam) to be generated and provided to a second beam path system 66 configured to provide the second manipulation signal to the cooling area. One of the first beam path system or the second beam path system is configured to provide the respective manipulation signal to the cooling area as a standing wave, higher-order optical mode, or other spatially structured optical field having one or more effective intensity minima and / or nulls at the target location(s) 125.

[0119] The first manipulation signal is characterized by a first frequency that is detuned from a transition between a first state and an excited state of the coolant object and the second manipulation signal is characterized by a second frequency that is detuned from a transition between a second state and the excited state of the coolant object. The first frequency and the second frequency are configured to cause the coolant object to undergo a two-photon virtual transition (i.e., a red sideband transition 252) between the first state and the second state that is mediated by the excited state. The first frequency and the second frequency are selected such that the effective detuning of the two-photon virtual transition (i.e., a red sideband transition) between the first state and the second state corresponds to at least one motional mode frequency corresponding to a motional mode of the object crystal to be cooled. For example, the motional mode may be a center-of-mass axial mode, a stretch axial mode, a radial mode, and / or the like.

[0120] After the first manipulation signal and the second manipulation signal have been provided to the cooling area for a cooling time, the controller 30 may control operation of the manipulation sources 64 and, possibly, beam path systems 66 to cause the first manipulation signal and the second manipulation signal to stop being provided to the cooling area, at step 706. Notably, as a result of the coupling rate of the carrier transition 254 being approximately zero due to the spatially structured optical field of one of the first manipulation signal or the second manipulation signal having one or more effective intensity minims or nulls at the target location(s) 125 at which the one or more coolant objects are located, the cooling time of an example embodiment may be 10 to 100 times shorter than conventional cooling times for conventional resolved sideband cooling.

[0121] For example, the controller 30 comprises means, such as processing device 805, memory 810, driver controller elements 815, and / or the like for determining when the first manipulation signal and the second manipulation signal have been provide to the cooling area for a cooling time and controlling operation of one or more manipulation sources 64 and / or beam path systems 66 to cause the first manipulation signal and the second manipulation signal to stop being provided to the cooling area.

[0122] At step 708, the controller 30 may cause performance of a quantum operation on the at least one qubit object of the selected object crystal. For example, the quantum operation may be a state preparation operation, single qubit gate, two-qubit gate, reading operation, and / or combination or sequence thereof. For example, the controller 30 may be causing the quantum processor 115 to perform quantum circuit and / or computation which includes performance of a sequence of quantum operations on various qubit objects confined by the confinement apparatus 120. For example, the controller 30 may control operation of the confinement apparatus 120 (e.g., via controlling operation of one or more voltage sources 50 configured to generate voltage signals applied to respective electrodes of the confinement apparatus, in an example embodiment) and / or manipulation sources 64to cause a quantum operation to be performed on the at least one qubit object of the selected object crystal. For example, the controller 30 comprises means, such as processing device 805, memory 810, driver controller elements 815, A / D converter 825, and / or the like, for causing performance of a quantum operation on the at least one qubit object of the selected object crystal.

[0123] At step 710, the controller 30 may cause the selected object crystal to be transported out of the cooling area. For example, the selected object crystal may betransported to a storage area, a gating area, reading / measurement area, state preparation area, another cooling area, and / or other portion of the confinement apparatus 120. For example, the controller 30 may control operation of the one or more voltage sources 50 to cause the one or more voltage sources 50 to generate voltage signals, which are applied to respective electrodes of the confinement apparatus 120, to generate a pseudopotential that causes the selected object crystal to be transported out of the cooling area. For example, the controller 30 may comprise means, such as processing device 805, memory 810, driver controller elements 815, and / or the like, for controlling operation of the confinement apparatus 120 to cause the selected object crystal to be transported out of the cooling area.Technical Advantages

[0124] Laser cooling includes causing one or more laser beams to be incident on a coolant object that cause the coolant object to undergo a transition that results in a reduction in the phonon population of a motional mode of the object crystal. For example, as shown in Figure 2B, the coolant object may be caused to undergo a sideband transition 252 from state |a, n>, where |a> is an internal quantum state of the coolant object and n is a phonon population of the object crystal, to a state |b, n-l>, where |b> is a different internal quantum state of the coolant object that is of higher energy than state |a>. Thus, the phonon population of the object crystal is reduced by the coolant object undergoing the sideband transition 252. The quantum state of the coolant object is adjusted from state |b> to state |a> and the process may be repeated to further cool (i.e., reduce the phonon population of) the object crystal.

[0125] However, the one or more laser beam used to drive the sideband transition 252 may also off-resonantly drive a carrier transition 254 such that the object crystal transitions from state |a, n> to state |b, n>. In other words, the carrier transition 254 results in the transition from state |a> to state |b>, but does not cool (i.e., reduce the phonon population of) the object crystal. The one or more laser beams used to drive the sideband transition couple more strongly to the carrier transition than to the cooling sideband transition. For example, the one or more laser beams may be ten to twenty more times more likely to drive the carrier transition than the sideband transition. This results in cooling operations can take a significant amount of time to perform. Therefore, technical problems exist regarding how to efficiently and / or quickly cool an object crystal.

[0126] Various embodiments provide technical solutions to these technical challenges.In various embodiments, an object crystal is confined by a confinement apparatus such that the coolant object is located at a target location defined at least in part by the confinement apparatus. A first manipulation signal and a second manipulation signal are caused to be incident on the object crystal and / or the coolant object. The first manipulation signal is red detuned from a first transition between a first quantum state of the coolant object and an excited state of the coolant object and the second manipulation is red detuned from a second transition between a second quantum state of the coolant object and the excited state of the coolant object. When the first manipulation signal and the second manipulation signal are applied to the coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal. For example, the first manipulation signal and the second manipulation signal are configured to cause the coolant object to experience a two- photon red sideband transition 252.

[0127] The first manipulation signal is provided to the cooling area as a spatially structured optical field. For example, the spatially structured optical field includes one or more spatially stable intensity minima or nulls. In other words, the intensity of the spatially structured optical field is approximately zero at at least one location within the cooling area. In various embodiments, the intensity minima or nulls of the spatially structured optical field are located at, disposed at, and / or coincide with respective target locations. The one or more coolant objects of an object crystal are confined such that the coolant objects are located at respective target locations (e.g., at intensity minima and / or nulls of the spatially structured optical field).

[0128] The amplitude / magnitude gradient of the spatially structured optical field is nonzero at the intensity minima and / or nulls such that the first manipulation signal and the second manipulation signal being incident on the cooling object causes the coolant object to undergo the red sideband transition 252, but to not undergo the carrier transition 254. For example, the coupling rate of the carrier transition is decreased to approximately zero.

[0129] The decreased coupling rate of the carrier transition 254 results in the cooling of the object crystal being significantly more effective and / or time-efficient. In particular, the time required to cool an object crystal can be reduced by a factor of 10 to 100 by reducing the coupling rate of the carrier transition 254 to approximately zero. For example, a conventional cooling operation may take 10 to 100 times longer to perform than a coolingoperation of an example embodiment that provides the first manipulation signal to the object crystal as a spatially structured optical field.

[0130] By decreasing cooling operation times by a factor of 10 to 100, various embodiments provide technical improvements to fields that use laser cooling to cool quantum and / or atomic objects. For example, various embodiments provide technical improvements to atomic and / or quantum systems, such as QCCD-based quantum computers, for example, that use laser cooling (e.g., sympathetic laser cooling) to cool quantum and / or atomic objects used for performance of experiments and / or storing of quantum information (e.g., used as qubits).Example Controller

[0131] In various embodiments, a quantum computer 110 comprises a controller 30 configured to control various elements and / or components of the quantum processor 115. In various embodiments, a controller 30 may be configured to cause a quantum computer 110 to perform various operations (e.g., cooling operations using a spatially structured optical field, computing operations such as single qubit and / or two-qubit gates, transport operations, qubit interaction operations, qubit reading operations, leakage suppression operations, and / or the like). For example, the controller 30 may be configured to cause one or more manipulation sources 64 to provide first and second manipulation sources to a cooling area, in accordance with an example embodiment. In various embodiments, the controller 30 may be configured to control operation of a cryogenic system and / or vacuum system controlling the temperature and pressure within the cryogenic and / or vacuum chamber 40, manipulation sources 64, beam path systems 66, confinement apparatus 120, and / or other systems controlling the environmental conditions (e.g., temperature, humidity, pressure, and / or the like) within the cryogenic and / or vacuum chamber 40 and / or configured to manipulate and / or cause a controlled evolution of quantum states of one or more qubit objects 5 and / or use one or more coolant objects 10 to cool qubit objects 5 via sympathetic laser cooling using a spatially structured optical field.

[0132] As shown in Figure 8, in various embodiments, the controller 30 may comprise various controller elements including processing device 805, memory 810, driver controller elements 815, a communication interface 820, analog-digital converter elements 825, and / or the like. For example, the processing device 805 may comprise one or more processing elements such as programmable logic devices (CPLDs), microprocessors, coprocessing entities, application-specific instruction-set processors (ASIPs), integrated circuits, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs),programmable logic arrays (PLAs), hardware accelerators, other processing devices and / or circuitry, and / or the like, and / or controllers. The term circuitry may refer to an entirely hardware embodiment or a combination of hardware and computer program products. In an example embodiment, the processing device 805 of the controller 30 comprises a clock and / or is in communication with a clock.

[0133] For example, the memory 810 may comprise non-transitory (classical and / or semiconductor-based) memory such as volatile and / or non-volatile memory storage such as one or more of as hard disks, ROM, PROM, EPROM, EEPROM, flash memory, MMCs, SD memory cards, Memory Sticks, CBRAM, PRAM, FeRAM, RRAM, SONOS, racetrack memory, RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM, RDRAM, RIMM, DIMM, SIMM, VRAM, cache memory, register memory, and / or the like. In various embodiments, the memory 810 may store qubit records corresponding the qubits of quantum computer (e.g., in a qubit record data store, qubit record database, qubit record table, and / or the like), a calibration table, an executable queue, computer program code (e.g., in a one or more computer languages, specialized controller language(s), and / or the like), and / or the like. In an example embodiment, execution of at least a portion of the computer program code stored in the memory 810 (e.g., by a processing device 805) causes the controller 30 to perform one or more steps, operations, processes, procedures and / or the like described herein.

[0134] In various embodiments, the driver controller elements 815 may include one or more drivers and / or controller elements each configured to control one or more drivers. In various embodiments, the driver controller elements 815 may comprise drivers and / or driver controllers. For example, the driver controllers may be configured to cause one or more corresponding drivers to be operated in accordance with executable instructions, commands, and / or the like scheduled and executed by the controller 30 (e.g., by the processing device 805).

[0135] In various embodiments, the driver controller elements 815 may enable the controller 30 to operate manipulation sources 64, beam path systems 66, voltage sources 50, the confinement apparatus 120, vacuum and / or cryogenic systems, and / or the like. In various embodiments, the drivers may be laser drivers; microwave drivers; vacuum component drivers; cryogenic and / or vacuum system component drivers; current drivers; potential drivers; voltage sources; and / or the like. For example, the drivers and / or driver controllers may be configured to cause the magnetic field generation device (e.g., comprising circuitry coupled to a voltage source (e.g., a current driver or voltage driver),permanent magnet(s), and / or a combination thereof) to generate a magnetic field having a particular direction and magnitude at one or more positions of the confinement apparatus 120.

[0136] In various embodiments, the controller 30 comprises means for communicating and / or receiving signals from one or more optical receiver components such as photodetectors, cameras, MEMs cameras, CCD cameras, photodiodes, photomultiplier tubes, and / or the like. For example, the controller 30 may comprise one or more analogdigital converter elements 825 configured to receive signals from one or more optical receiver components, calibration sensors, and / or the like.

[0137] In various embodiments, the controller 30 may comprise a communication interface 820 for interfacing and / or communicating with a computing entity 25. For example, the controller 30 may comprise a communication interface 820 for receiving executable instructions, command sets, and / or the like from the computing entity 25 and providing output received from the quantum computer 110 (e.g., from an optical collection system) and / or the result of a processing the output to the computing entity 25. In various embodiments, the computing entity 25 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.Exemplary Computing Entity

[0138] Figure 9 provides an illustrative schematic representative of an example computing entity 25 that can be used in conjunction with embodiments of the present invention. In various embodiments, a computing entity 25 is configured to allow a user to provide input to the quantum computer 110 (e.g., via a user interface of the computing entity 25) and receive, display, analyze, and / or the like output from the quantum computer 110. For example, a user may operate a computing entity 25 to generate and / or program a quantum algorithm and / or quantum circuit (e.g., that includes one or more cooling operations using a spatially structured optical field) that may be provided such that the controller 30 may receive the quantum algorithm and / or quantum circuit and cause the quantum computer 110 to perform the quantum algorithm and / or quantum circuit.

[0139] As shown in Figure 9, a computing entity 25 can include an antenna 912, a transmitter 904 (e.g., radio), a receiver 906 (e.g., radio), and a processing device 908 that provides signals to and receives signals from the transmitter 904 and receiver 906, respectively. The signals provided to and received from the transmitter 904 and thereceiver 906, respectively, may include signaling information / data in accordance with an air interface standard of applicable wireless systems to communicate with various entities, such as a controller 30, other computing entities 25, and / or the like.

[0140] In this regard, the computing entity 25 may be capable of operating with one or more air interface standards, communication protocols, modulation types, and access types. For example, the computing entity 25 may be configured to receive and / or provide communications using a wired data transmission protocol, such as fiber distributed data interface (FDDI), digital subscriber line (DSL), Ethernet, asynchronous transfer mode (ATM), frame relay, data over cable service interface specification (DOCSIS), or any other wired transmission protocol.

[0141] Similarly, the computing entity 25 may be configured to communicate via wireless external communication networks 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 IX (IxRTT), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), Time Division-Synchronous Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Evolution-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) protocols, near field communication (NFC) protocols, Wibree, Bluetooth protocols, wireless universal serial bus (USB) protocols, and / or any other wireless protocol. The computing entity 25 may use such protocols and standards to communicate using Border Gateway Protocol (BGP), Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), File Transfer Protocol (FTP), Hypertext Transfer Protocol (HTTP), HTTP over TLS / SSL / S ecure, 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 Transmission Protocol (SCTP), HyperText Markup Language (HTML), and / or the like. In various embodiments, the computing entity 25 includes a network interface 920 configured to enable the computing entity 25 to communicate via one or more wired and / or wireless networks.

[0142] Via these communication standards and protocols, the computing entity 25 cancommunicate with various other entities using concepts such as Unstructured Supplementary Service information / data (USSD), Short Message Service (SMS), Multimedia Messaging Service (MMS), Dual-Tone Multi -Frequency Signaling (DTMF), and / or Subscriber Identity Module Dialer (SIM dialer). The computing entity 25 can also download changes, add-ons, and updates, for instance, to its firmware, software (e.g., including executable instructions, applications, program modules), and operating system.

[0143] In various embodiments, the computing entity comprises a processing device 908. For example, the processing device 908 may comprise one or more processing elements such as programmable logic devices (CPLDs), microprocessors, coprocessing entities, application- specific instruction-set processors (ASIPs), integrated circuits, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), hardware accelerators, other processing devices and / or circuitry, and / or the like, and / or controllers. The term circuitry may refer to an entirely hardware embodiment or a combination of hardware and computer program products.

[0144] The computing entity 25 may also comprise a user interface device comprising one or more user input / output interfaces (e.g., a display 916 and / or speaker / speaker driver coupled to a processing device 908 and a touch screen, keyboard, mouse, and / or microphone coupled to a processing device 908). For instance, the user output interface may be configured to provide an application, browser, user interface, interface, dashboard, screen, webpage, page, and / or similar words used herein interchangeably executing on and / or accessible via the computing entity 25 to cause display or audible presentation of information / data and for interaction therewith via one or more user input interfaces. The user input interface can comprise any of a number of devices allowing the computing entity 25 to receive data, such as a keypad 918 (hard or soft), a touch display, voice / speech or motion interfaces, scanners, readers, or other input device. In embodiments including a keypad 918, the keypad 918 can include (or cause display of) the conventional numeric (0- 9) and related keys (#, *), and other keys used for operating the computing entity 25 and may include a full set of alphabetic keys or set of keys that may be activated to provide a full set of alphanumeric keys. In addition to providing input, the user input interface can be used, for example, to activate or deactivate certain functions, such as screen savers and / or sleep modes. Through such inputs the computing entity 25 can collect information / data, user interaction / input, and / or the like.

[0145] The computing entity 25 can also include volatile storage or memory 922 and / or non-volatile storage or memory 924, which can be embedded and / or may be removable.For instance, the non-volatile memory may be ROM, PROM, EPROM, EEPROM, flash memory, MMCs, SD memory cards, Memory Sticks, CBRAM, PRAM, FeRAM, RRAM, SONOS, racetrack memory, and / or the like. The 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, and / or the like. The volatile and non-volatile storage or memory can store databases, database instances, database management system entities, data, applications, programs, program modules, scripts, source code, object code, byte code, compiled code, interpreted code, machine code, executable instructions, and / or the like to implement the functions of the computing entity 25.Conclusion

[0146] Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS1. A system configured for performing sympathetic laser cooling, the system comprising: a confinement apparatus configured to confine an object crystal comprising at least one qubit object and at least one coolant object with the at least one coolant object located at a target location within a cooling area defined at least in part by the confinement apparatus; one or more manipulation sources configured to generate a first manipulation signal and a second manipulation signal, wherein the first manipulation signal is red detuned from a first transition between a first quantum state of the at least one coolant object and an excited state of the at least one coolant object and the second manipulation signal is red detuned from a second transition between a second quantum state of the at least one coolant object and the excited state of the at least one coolant object such that when the first manipulation signal and the second manipulation signal are applied to the at least one coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the at least one coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal; and one or more beam path systems, wherein the one or more beam path systems define one or more beam paths configured to provide the first manipulation signal and the second manipulation signal to the cooling area and one of the first manipulation signal or the second manipulation signal is provided by the one or more beam path systems as a spatially structured optical field within the cooling area.

2. The system of claim 1, wherein the target location at which the at least one coolant object is confined is located at an intensity minima of the spatially structured optical field.

3. The system of claim 2, wherein a gradient of the spatially structured optical field at the target location is non-zero.

4. The system of claim 1, wherein the spatially structured optical field is a spatial phase stable optical field such that a spatial phase of the spatially structured optical field is stable in time within the cooling area while the first manipulation signal is being provided to thecooling area.

5. The system of claim 1, wherein the motional mode frequency corresponds to at least one motional mode corresponding to movement of the object crystal, the at least one qubit object and / or the at least one coolant object along a corresponding motional mode axis.

6. The system of claim 5, wherein the one or more beam paths are configured to provide at least one of the first manipulation signal or the second manipulation signal such that an amplitude gradient of the spatially structured optical field has a non-zero projection onto the motional mode axis of the motional mode at the target location.

7. The system of claim 5, wherein the spatially structured optical field is a standing wave characterized by a spatial phase that evolves along an axis which has a non-zero projection along the corresponding motional mode axis.

8. The system of claim 1, wherein the first manipulation signal is provided to the cooling area as a travelling wave characterized by a higher-order optical mode having one or more stable intensity minima.

9. The system of claim 1, wherein the red effective detuning is configured to enable effective cooling of more than one motional mode of the object crystal.

10. The system of claim 1, wherein the one or more beam paths are configured to provide at least one of the first manipulation signal or the second manipulation signal such that an amplitude gradient of the spatially structured optical field has a first non-zero projection onto a first motional mode axis corresponding to a first motional mode of the object crystal and has a second non-zero projection onto a second motional mode axis corresponding to a second motional mode of the object crystal.

11. The system of claim 10, wherein the first motional mode axis is substantially perpendicular to the second motional mode axis.

12. The system of claim 1, wherein one or more components of the one or more beam path systems is an optical component that is housed on a first substrate that houses the confinement apparatus or housed on a second substrate that is secured in relation to the first substrate.

13. The system of claim 12, wherein at least one component of the one or more components is configured to cause an optical mode of the first manipulation signal to be a higher-order optical mode having a stable intensity minima.

14. The system of claim 13, wherein the at least one component is configured to provide the first manipulation signal to the cooling area in a direction that is not co-linear or not aligned with a motional mode axis corresponding to the motional mode frequency.

15. The system of claim 12, wherein the one or more components comprises a first component configured to cause a first portion of the first manipulation signal to be provided to the cooling area in a first direction and a second component configured to cause a second portion of the first manipulation signal to be provided to the cooling area in a second direction such that a difference wave vector between the first portion of the first manipulation signal and the second portion of the first manipulation signal has a non-zero projection along a motional mode axis corresponding to a motional mode of the object crystal, the first direction being different from the second direction.

16. The system of claim 15, wherein the one or more beam path systems define a first source beam path configured to direct the first manipulation signal from a first manipulation source of the one or more manipulation sources that generated the first manipulation signal to a beam splitter configured to split the first manipulation signal into the first portion and the second portion, a first beam path configured to provide the first portion to the first component, and a second beam path configured to provide the second portion to the second component.

17. The system of claim 12, wherein the one or more components comprise a third component configured to provide the second manipulation signal to the cooling area.

18. The system of claim 17, wherein the one or more beam path systems define a second source beam path configured to direct the second manipulation signal from a second manipulation source of the one or more manipulation sources and that generated the second manipulation signal to the third component.

19. A method for performing sympathetic laser cooling, the method comprising: controlling operation of a confinement apparatus to cause an object crystalcomprising at least one qubit object and at least one coolant object to be confined within a cooling area with the at least one coolant object confined at a target location defined at least in part by the confinement apparatus; and controlling operation of one or more manipulation sources and, optionally, one or more beam path systems, to cause a first manipulation signal and a second manipulation signal to start to be provided to the cooling area, wherein the first manipulation signal is red detuned from a first transition between a first quantum state of the at least one coolant object and an excited state of the at least one coolant object and the second manipulation signal is red detuned from a second transition between a second quantum state of the at least one coolant object and the excited state of the at least one coolant object such that when the first manipulation signal and the second manipulation signal are applied to the at least one coolant object, the first manipulation signal and the second manipulation signal collectively drive a sideband transition of the at least one coolant object between the first quantum state and the second quantum state that is characterized by a red effective detuning that corresponds to at least one motional mode frequency of the object crystal, and the one or more beam path systems define one or more beam paths configured to provide one of the first manipulation signal or the second manipulation signal as a spatially structured optical field within the cooling area.

20. The method of claim 19, further comprising, responsive to processing a cooling stop trigger, controlling operation of the one or more manipulation sources, and optionally, the one or more beam path systems, to cause the first manipulation signal and the second manipulation signal to stop being provided to the cooling area.

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