Atomic system and atomic arrangement method

Abstract

The invention discloses an atom system and an atom arrangement method, and relates to the technical field of quantum computing. The atom system captures atoms by adopting first optical tweezers and second optical tweezers which are paired one by one, so that single atoms captured by the first optical tweezers are bound to a first layer of the atom array, and atom ensembles captured by the second optical tweezers are bound to a second layer of the atom array. The atomic system rearranges the initially loaded first atomic array by using internal state dependent array light, and moves atoms in the atomic ensemble in the second layer to the first optical tweezers vacant in the first layer, thereby successfully loading the physical bits matched with the first information to the plurality of first optical tweezers. Wherein the internal state dependent array light moves a plurality of atoms in the second layer in parallel, the internal state dependent array light does not need to move atoms from the outside of the atom array one by one, and does not need to serially fill the vacant first optical tweezers in the atom array, so that the problems that the quantum bit array is relatively long in loading time and relatively low in atom loading efficiency are solved.

Description

Technical Field

[0001] This application relates to the field of quantum computing technology, and in particular to an atomic system and a method for arranging atoms. Background Technology

[0002] With the continuous development of technology, traditional computer computing can no longer meet the computational demands of resource-intensive tasks, such as quantum chemical simulation, optimal path finding, and large number factorization. Quantum computing systems based on neutral atom architectures (neutral atom systems) have emerged to address this need. Neutral atom systems use an objective lens to focus trapped light, forming optical tweezers. These tweezers capture laser-cooled atoms, with each captured atom corresponding to a qubit. The atoms are neatly arranged in a vacuum glass cavity, forming a qubit array. Typically, irradiating the atoms in the array with global and addressing light allows for parallel or independent operations on the qubits, such as changing their state (0, 1, or a superposition of 0 and 1). During qubit readout, irradiating the atoms in the array with probe light yields scattered photons. The electron signal is determined based on the photons collected from the objective lens, and the state of the qubit is determined based on this signal, thus obtaining the result of the quantum computation.

[0003] The atom loading process involves using highly focused optical tweezers generated by an acousto-optic deflector (AOD) to move atoms from outside the target region to a static optical tweezer trap within the target region. This allows the loaded qubit array in the target region to match the input information for quantum computing, enabling the qubit array to participate in quantum computation. As the size of the qubit array increases, the number of atom movements and the distance moved by the AOD increase significantly, resulting in longer loading times and lower atom loading efficiency. Summary of the Invention

[0004] This application provides an atomic system and atomic arrangement method, which solves the problems of long loading time and low efficiency of atomic loading in quantum bit arrays.

[0005] The technical solution adopted in this application is as follows.

[0006] In a first aspect, this application provides an atomic system. The atomic system includes: an atomic source, an atomic cavity, a first optical module, and a second optical module. The atomic source provides multiple atoms. The atomic cavity is connected to the atomic source and stores the atoms provided by the atomic source. The first optical module generates multiple optical tweezers within the atomic cavity and arranges the multiple optical tweezers according to first information to obtain a first atomic array. The first atomic array includes a first layer and a second layer in a first region. The first layer includes N first optical tweezers, and the second layer includes N second optical tweezers. The first and second optical tweezers are paired one-to-one. Each first optical tweezer is used to capture one atom, and each second optical tweezer is used to capture a set of atomic ensembles. The first layer includes M atoms, and the second layer includes N sets of atomic ensembles, where N ≥ M. The second optical module emits internal state-dependent array light into the atomic cavity, causing the first atomic array to rearrange to obtain the second atomic array. In the second atomic array, the first layer comprises N atoms, which include M atoms and NM atoms in the first layer whose internal state depends on the array light moving from the NM atomic ensembles. One atom among the N atoms represents a physical bit. In the second atomic array, the second layer comprises N atomic ensembles, and one set of atomic ensembles from the N atomic ensembles represents an auxiliary bit paired with a physical bit. The physical bit represented by the N atoms matches the first information, and the number of atoms in the first atomic array is the same as the number of atoms in the second atomic array.

[0007] In the first aspect of this application, the atomic system employs paired first and second optical tweezers to capture atoms, such that the single atoms captured by each first optical tweezer are bound to the first layer of the atomic array, and the ensembles of atoms captured by each second optical tweezer are bound to the second layer of the atomic array. Since there is a certain failure probability in the process of capturing single atoms with the first optical tweezers, some first optical tweezers in the first layer fail to capture single atoms. Therefore, the atomic system uses internal state-dependent array light to rearrange the initially loaded first atomic array, moving atoms from the atomic ensembles in the second layer to the first layer, thereby successfully loading the physical bits matching the first information into multiple first optical tweezers in the first layer. During the rearrangement of the atomic array, the internal state-dependent array light can move multiple atoms in the second layer in parallel (such as the NM atoms mentioned above), so that the physical bits represented by the rearranged atomic array match the first information. The internal state-dependent array light does not need to move atoms one by one from outside the atomic array, nor does it need to sequentially fill the first optical tweezers in the first atomic array that have not captured atoms, thus solving the problems of long loading time and low atomic loading efficiency of quantum bit arrays.

[0008] In conjunction with the atomic system provided in the first aspect, in one optional implementation, the atomic system provided in this application further includes: a third optical module and a qubit measurement unit. The third optical module is used to generate global light based on the second information, and the global light is used to irradiate the second atomic array. The qubit measurement unit is used to collect scattered photons generated in the second atomic array after being irradiated by the probe beam, and to determine the quantum computing result between the first and second information based on the scattered photons. During the atomic arrangement process of quantum computing, the atomic system uses the second optical module to emit internal state-dependent array light to rearrange the atomic array. During the rearrangement process, multiple atoms can be moved in parallel, so that the physical bits represented by the rearranged atomic array match the first information, reducing the arrangement time of the atomic array, which is beneficial for reducing the latency of quantum computing and improving the efficiency of quantum computing.

[0009] In conjunction with the atomic system provided in the first aspect, in one optional implementation, the atomic system provided in this application further includes: a state preparation optical module, which is used to send state preparation light to the atomic cavity to prepare all atoms in the first atomic array into a first state. A second optical module is specifically used to: emit first atomic Rydberg light to the atomic cavity to excite M atoms in the first layer of the first atomic array to a second state; emit first ensemble array Rydberg light to the atomic cavity to excite NM atoms in the unpaired physical bit ensemble of the first atomic array to a second state, while atoms in the paired physical bit ensemble will not be excited to a second state; emit second ensemble array Rydberg light to the atomic cavity to de-excite NM atoms to a third state; emit second atomic Rydberg light to the atomic cavity to de-excite M atoms to a first state; and emit internal state-dependent array light to the atomic cavity to move the NM atoms in the third state of the first atomic array to the first layer to obtain a second atomic array.

[0010] For example, the first state is the |1> state, the second state is the |r> state, and the third state is the |0> state.

[0011] In the first aspect of this application, for an atomic array of the same composition, for the first optical tweezers in the first layer where no atoms are captured, since only the atoms to be filled (such as atoms in the third state) are affected by the internal state-dependent array light, the internal state-dependent array light can simultaneously move atoms in the third state within the entire target area (first region) in parallel, and the path is fixed. Therefore, the atomic system does not need to perform path calculations for the atoms, reducing the time required for atomic arrangement. Even if the size of the atomic array increases, the time required for atomic arrangement is only the fixed time of a single parallel movement; the time required for atomic arrangement does not increase with the size of the atomic array.

[0012] In conjunction with the atomic system provided in the first aspect, in one alternative implementation, in the second atomic array, for the first atom among the NM atoms contained in the first layer, the first atom is moved from the first atomic ensemble in the second layer to the first layer after being irradiated by the internal state dependent array light, and the first optical tweezers that capture the first atom are paired with the second optical tweezers that capture the first atomic ensemble.

[0013] In conjunction with the atomic system provided in the first aspect, in one optional implementation, the wavelength of the internal state-dependent array light is one of a plurality of predetermined values, which are determined according to the atom types in the first atomic array, and the plurality of values ​​include the first wavelength. For example, if the internal state-dependent array light is the first wavelength, the internal state-dependent array light will move atoms in the third state but will not move atoms in the first state.

[0014] In conjunction with the atomic system provided in the first aspect, in one optional implementation, the first layer and the second layer are arranged in three dimensions: the first layer and the second layer are located in different planes, and an atom in the first layer and an ensemble of atoms paired with an atom in the second layer have a first bias value along a first direction, which is a direction perpendicular to the first layer and the second layer.

[0015] In conjunction with the atomic system provided in the first aspect, in one optional implementation, the first layer and the second layer are arranged in two dimensions: the first layer and the second layer are located in the same plane, and there is a second bias value between an atom in the first layer and a group of atoms in the second layer that are paired with an atom, such as the second bias value between the first atom in the first layer and the first group of atoms in the second layer, and the first optical tweezers for capturing the first atom are paired with the second optical tweezers for capturing the first group of atoms.

[0016] Secondly, this application provides an atomic arrangement method. This atomic arrangement method is applied to an atomic system, which includes an atomic source, an atomic cavity, a first optical module, and a second optical module, with the atomic cavity connected to the atomic source. The atomic arrangement method provided in this application includes: the atomic source providing multiple atoms to the atomic cavity; the first optical module generating multiple optical tweezers within the atomic cavity; and arranging the multiple optical tweezers according to first information to obtain a first atomic array. The first atomic array includes a first layer and a second layer in a first region. The first layer includes N first optical tweezers, and the second layer includes N second optical tweezers. The first and second optical tweezers are paired one-to-one. Each first optical tweezer is used to capture one atom, and each second optical tweezer is used to capture a set of atomic ensembles. The first layer includes M atoms, and the second layer includes N sets of atomic ensembles, where N ≥ M. Furthermore, the second optical module emits internal state-dependent array light into the atomic cavity, causing the first atomic array to rearrange to obtain the second atomic array. In the second atomic array, the first layer comprises N atoms, including M atoms and NM atoms in the first layer whose internal state depends on the array light moving from the NM atomic ensembles. One atom among the N atoms represents a physical bit. In the second atomic array, the second layer comprises N atomic ensembles, and one set of atomic ensembles from the N atomic ensembles represents an auxiliary bit paired with a physical bit. The physical bit represented by the N atoms matches the first information, and the number of atoms in the first atomic array is the same as the number of atoms in the second atomic array.

[0017] In the second aspect of this application, the atomic system employs paired first and second optical tweezers to capture atoms, such that the single atoms captured by each first optical tweezer are bound to the first layer of the atomic array, and the ensembles of atoms captured by each second optical tweezer are bound to the second layer of the atomic array. Since there is a certain failure probability in the process of capturing single atoms with the first optical tweezers, some first optical tweezers in the first layer fail to capture single atoms. Therefore, the atomic system uses internal state-dependent array light to rearrange the initially loaded first atomic array, moving atoms from the second-layer ensemble to the first layer, thereby successfully loading the physical bits matching the first information into multiple first optical tweezers in the first layer. During the rearrangement of the atomic array, the internal state-dependent array light can move multiple atoms in the second layer in parallel (such as the NM atoms mentioned above), ensuring that the physical bits represented by the rearranged atomic array match the first information. The internal state-dependent array light does not need to move atoms one by one from outside the atomic array, nor does it need to sequentially fill the first optical tweezers in the first atomic array that have not captured atoms, thus solving the problems of long loading time and low atomic loading efficiency of quantum bit arrays.

[0018] In conjunction with the atomic arrangement method provided in the second aspect, in an optional implementation, the aforementioned atomic system further includes a third optical module and a qubit measurement unit. The atomic arrangement method provided in this application further includes: the third optical module generating global light based on the second information, the global light being used to irradiate the second atomic array; and the qubit measurement unit collecting scattered photons generated in the second atomic array after irradiation by the probe beam, and determining the quantum computing result between the first and second information based on the scattered photons. During the atomic arrangement process, the atomic system uses the second optical module to emit internal state-dependent array light to rearrange the atomic array. During the rearrangement process, multiple atoms can be moved in parallel, allowing the physical bits represented by the rearranged atomic array to match the first information, reducing the arrangement time of the atomic array, which is beneficial for reducing the latency of quantum computing and improving the efficiency of quantum computing.

[0019] In conjunction with the atomic arrangement method provided in the second aspect, in an optional implementation, the aforementioned atomic system further includes a state preparation optical module. Before the rearrangement of the first atomic array, the atomic arrangement method provided in this application further includes: the state preparation optical module sending state preparation light to the atomic cavity to prepare all atoms in the first atomic array into a first state; the second optical module emitting first atomic Rydberg light to the atomic cavity to excite M atoms in the first layer of the first atomic array to a second state; the second optical module emitting first ensemble array Rydberg light to the atomic cavity to excite NM atoms in the unpaired physical bit ensemble of the first atomic array to a second state, while atoms in the paired physical bit ensemble are not excited to a second state; the second optical module emitting second ensemble array Rydberg light to the atomic cavity to de-excite NM atoms to a third state; and the second optical module emitting second atomic Rydberg light to the atomic cavity to de-excite M atoms to a first state. Furthermore, the second optical module emits internal state-dependent array light into the atomic cavity, moving NM atoms in the third state of the first atomic array to the first layer to obtain the second atomic array.

[0020] In the second aspect of this application, for an atomic array of the same composition, for the first optical tweezers in the first layer where no atoms are captured, since only the atoms to be filled (such as atoms in the third state) are affected by the internal state-dependent array light, this internal state-dependent array light can simultaneously move in parallel on all atoms in the third state within the entire target area (first region) along a fixed path. Therefore, the atomic system does not need to perform path calculations for the atoms, reducing the time required for atomic arrangement. Even if the size of the atomic array increases, the time required for atomic arrangement is only the time of a single parallel movement; the time required for atomic arrangement does not increase with the size of the atomic array.

[0021] In one optional implementation, combining the atomic system provided in the first aspect or the atomic arrangement method provided in the second aspect, the second region covered by the internal state-dependent array light includes the first region. Thus, atoms in the third state within the atomic array located in the first region can be controlled by the internal state-dependent array light, which does not move atoms in other states. This achieves atomic rearrangement for specific internal states within the atomic array, which helps reduce the time required for atomic rearrangement and improves the efficiency of quantum computing.

[0022] In an alternative implementation, combining the atomic system provided in the first aspect or the atomic arrangement method provided in the second aspect, the internal state-dependent array light is constrained as optical tweezers or an optical lattice. Optical tweezers refer to micrometer-scale (or larger or smaller) light spots obtained by focusing parallel laser light through a microscope. These spots can be used to form three-dimensional optical potential wells, where atoms can be confined to the lowest potential energy points. An optical lattice refers to loading cold atoms into a periodic mesh-like potential well formed by the interference of multiple laser beams, creating a spatially periodic arrangement of atoms, similar to a "crystal structure" in solid-state physics.

[0023] In one optional implementation, combining the atomic system provided in the first aspect or the atomic arrangement method provided in the second aspect, the first information is the input information of the quantum computing process.

[0024] In one optional implementation, combining the atomic system provided in the first aspect or the atomic arrangement method provided in the second aspect, the first information is the adjustment information for the quantum error correction process.

[0025] In an optional implementation, in conjunction with the atomic system provided in the first aspect or the atomic arrangement method provided in the second aspect, the atoms provided by the aforementioned atomic source can be rubidium (Rb) atoms, ytterbium (Yb) atoms, cesium (Cs) atoms, or strontium (Sr) atoms, etc.

[0026] Based on the implementation methods provided in the above aspects, this application can be further combined to provide more implementation methods, which will not be elaborated here. Attached Figure Description

[0027] Figure 1 A schematic diagram of the different types of quantum numbers of atoms provided in this application.

[0028] Figure 2 A schematic diagram of the magnetic quantum number provided in this application.

[0029] Figure 3 A schematic diagram illustrating the energy difference and dipole moment of rubidium atoms provided in this application.

[0030] Figure 4 A schematic diagram of a CZ gate provided in this application.

[0031] Figure 5 A schematic diagram of the structure of an atomic system provided in this application Figure 1 .

[0032] Figure 6 This is a schematic diagram of the arrangement of the atomic array provided in this application.

[0033] Figure 7 This is a schematic diagram of the optical tweezers arrangement in the atomic array provided in this application.

[0034] Figure 8 A schematic diagram of the structure of an atomic system provided in this application Figure 2 .

[0035] Figure 9 A schematic diagram of the structure of an atomic system provided in this application Figure 3 .

[0036] Figure 10 This is a schematic diagram illustrating the implementation of the optical path modulation component provided in this application.

[0037] Figure 11 A schematic diagram of the three interatomic interaction forces provided in this application.

[0038] Figure 12 A schematic diagram of the structure of an atomic system provided in this application Figure 4 .

[0039] Figure 13 This is a flowchart illustrating a quantum computing method.

[0040] Figure 14 This is a schematic diagram of the loading of the optical tweezers and atomic array provided in this application.

[0041] Figure 15 This is a flowchart illustrating a quantum computing method provided in this application.

[0042] Figure 16 A schematic diagram of the structure of an atomic system provided in this application Figure 5 .

[0043] Figure 17 This is a schematic diagram of Rydberg excitation and internal state-dependent shift provided in this application.

[0044] Figure 18 This is a schematic diagram illustrating the rearrangement of an atomic arrangement method provided in this application.

[0045] Figure 19 This is a comparison diagram of different single-atom arrays provided in this application. Detailed Implementation

[0046] This application provides an atomic system and an atomic arrangement method. The atomic system uses paired first optical tweezers and second optical tweezers to capture atoms, such that the single atoms captured by each first optical tweezer are bound to the first layer of the atomic array, and the atomic ensembles captured by each second optical tweezer are bound to the second layer of the atomic array. Since there is a certain failure probability in the process of capturing single atoms by the first optical tweezers, some first optical tweezers in the first layer fail to capture single atoms. Therefore, the atomic system uses internal state-dependent array light to rearrange the initially loaded first atomic array, moving atoms from the atomic ensembles in the second layer to the first layer, thereby successfully loading the physical bits matching the first information into multiple first optical tweezers.

[0047] Specifically, during the rearrangement of the atomic array, the internal state-dependent array light can move multiple atoms in the second layer in parallel (such as the NM atoms mentioned above), so that the physical bits represented by the rearranged atomic array match the first information. The internal state-dependent array light does not need to move atoms one by one from outside the atomic array, nor does it need to fill the first optical tweezers in the first atomic array that have not captured atoms in sequence, thus solving the problems of long loading time and low efficiency of atomic loading of the quantum bit array.

[0048] This application may be applied not only to current quantum computing technologies or standards, but also to future quantum computing technologies or standards. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the application. A brief introduction to some concepts that may be involved in this application is provided below.

[0049] 1. Quantum bit: The basic building block of quantum information. Unlike classical bits in traditional binary computers, which can only be 0 or 1, a quantum bit can be in a state of 0 or 1, or a superposition of 0 and 1. Quantum bits can be carried by various carriers, including superconducting circuits, ions, atoms, photons, and quantum dots.

[0050] 2. Logic gate: The basic logical operation unit in quantum circuits.

[0051] 3. Energy levels: Relatively stable states in a quantum system. These states correspond to a series of discrete energies.

[0052] 4. Quantum state: The state of a quantum system characterized by a set of quantum numbers.

[0053] 5. Quantum number: A numerical value used to describe the conserved physical quantities in a quantum system, thereby expressing the quantum state of the system.

[0054] 6. Principal quantum number (n): One of the quantum numbers representing the atomic orbital domain, describing the electron shell in which the electron is located, its distance from the atomic nucleus, and its corresponding energy.

[0055] 7. Orbital quantum number (1): One of the quantum numbers representing the atomic orbital domain, describing the magnitude of the electron orbital angular momentum and the shape of its corresponding electron cloud.

[0056] 8. Magnetic quantum number (m): One of the quantum numbers representing the atomic orbital domain, describing the projection of the electron angular momentum into space and its corresponding equivalent magnetic moment.

[0057] 9. Ground state: The lowest energy quantum state of an atom in a quantum computing system / atomic system.

[0058] 10. Rydberg state: Generally refers to a highly excited state of an atomic or molecular system. Compared with the ground state, the electron cloud of an atom in the Rydberg state is increased by several orders of magnitude.

[0059] 11. Optical tweezers array: After a laser beam is highly focused by an objective lens, it can be used to trap atoms. Multiple optical tweezers can be arranged in an orderly manner to form an optical tweezers array; the optical tweezers refer to optical tweezers formed by focusing and trapping light through an objective lens.

[0060] 12. Components: In this article, these refer to isotopes or elements.

[0061] 13. Magneto-optical trap: Atoms are cooled and collected at the center of the magnetic field by a spatially varying magnetic field and laser cooling. The atomic temperature can be cooled to hundreds to several microkilograms. The magneto-optical trap is the first step in most atomic experiments.

[0062] 14. Hamiltonian: The total energy of a system, including the kinetic and potential energy of particles.

[0063] 15. Alkali metals: Alkali metals refer to the six metallic elements belonging to Group 1 of the periodic table: lithium, sodium, potassium, rubidium, cesium, and copper. All alkali metals have one outermost electron in the s orbital.

[0064] 16. Alkaline Earth Metals: Alkaline earth metals refer to the six metallic elements belonging to Group 2 of the periodic table: beryllium, magnesium, calcium, strontium, barium, and radium. All alkaline earth metals have two outermost electrons in the s orbital domain.

[0065] 17. Single-photon excitation: An atom absorbs a photon of excitation light from a lower-energy quantum state, thus being excited to a higher-energy quantum state. The frequency and polarization of the excitation photon determine the quantum state to which it is excited.

[0066] 18. Two-photon excitation: An atom is excited to a higher-energy quantum state by absorbing two photons of excitation light from a lower-energy quantum state. The frequency and polarization of the two photons together determine the quantum state to which it is excited.

[0067] 19. Dipole interaction: The interaction between two electric dipoles.

[0068] 20. C6: A commonly used parameter for the strength of interatomic interactions, such as the Rydberg state C6, which is approximately 100 GHz / (μm). 6 Magnitude.

[0069] 21. Polarization: The phenomenon that the spatial distribution of the electric vector vibration of a light wave loses symmetry with respect to the direction of light propagation is called light polarization. It is a phenomenon in which the vibration vector of the transverse wave of light (perpendicular to the direction of wave propagation) is deflected in certain directions.

[0070] 22. Optical frequency is short for light frequency. The product of optical frequency and wavelength is the speed of light (c = 299,792,458 m / s). In this article, optical frequency is also referred to as frequency, and will not be explained again hereafter.

[0071] 23. CZ Gate: A type of two-bit gate. The two bits are the control bit and the target bit, respectively. The effect of this gate operation is that when both bits are in the |1> state, the system increases the phase by π; otherwise, the system increases the phase by 0. Under the basis of |00>, |01>, |10>, |11>, the corresponding transition matrix is ​​a 4×4 diagonal matrix with diagonal elements {1,1,1,-1}.

[0072] 24. Rydberg interaction: The interaction between two atoms in a Rydberg state.

[0073] 25. Addressing Beam: Used to describe the spatial distribution characteristics of laser light. The addressing beam illuminates only specific atoms on the atomic array. Physically, this addressing beam can be a highly focused beam (e.g., a spot diameter of about one micrometer) that can be used to illuminate a single atom.

[0074] 26. Global Beam: Used to describe the spatial distribution characteristics of laser light. Global beam simultaneously illuminates all atoms on an atomic array. Physically, this global beam can be a large spot of light used to illuminate the entire atomic array for global manipulation.

[0075] 27. Resonance: The frequency of a laser beam is equal to the frequency corresponding to the energy difference between two energy levels. This condition is called resonance.

[0076] 28. Detuning: In the absence of resonance, the difference between the laser frequency and the frequency difference between the two energy levels. It is represented by the Greek letter Δ.

[0077] 29. Rabi frequency: A frequency parameter, equal to the angular frequency of the atomic state oscillation between two related energy levels under the influence of a laser, denoted by the Greek letter Ω.

[0078] 30. Blocking radius: A length parameter that depends on the Rydberg state of the atoms in the experiment and the Rabi frequency that excites the atoms from the ground state to the Rydberg state. The strength of the Rydberg interaction between atoms decreases with increasing distance. When the interatomic distance is one blocking radius, the interaction strength is exactly equal to the Rabi frequency.

[0079] 31. Rydberg blocking: refers to a physical phenomenon in which, when several atoms are all inside a circle with the blocking radius as the radius, only one atom can be excited to the Rydberg state, while the excitation of other atoms is blocked.

[0080] 32. π pulse: refers to a laser pulse with a duration of π / Ω.

[0081] 33. 2π pulse: refers to a laser pulse with a duration of 2π / Ω.

[0082] 34. Ensemble: In this article, it refers to multiple atoms simultaneously trapped in the same optical tweezers. When the beam waist of the optical tweezers is increased to several micrometers, photoinduced losses are significantly reduced, thus allowing multiple atoms to be loaded onto the same optical tweezers. In some cases, the ensemble can also be called an atomic ensemble.

[0083] The following description, in conjunction with the accompanying drawings, provides an exemplary account of the quantum states and their excitation processes, the ground states and Rydberg states of atoms, two-qubit gates, and the atomic systems and atom arrangement methods provided in the embodiments of this application.

[0084] I. Quantum states and the excitation process of quantum states.

[0085] Taking the alkali metal atom, the most common in neutral atom systems, as an example, the atom can be considered as consisting of a positively charged nucleus and a negatively charged electron. The principal quantum number *n* reflects the size of the electron cloud; as the principal quantum number increases, the electron cloud becomes more diffuse. The orbital quantum number reflects the shape of the electron cloud; as the orbital quantum number increases, the number of nodes increases accordingly, and the spatial distribution of the electron cloud becomes more complex. The quantum state with an orbital quantum number of zero is called the s-state, the quantum state with an orbital quantum number of one is called the p-state, and the quantum state with an orbital quantum number of two is called the d-state. The magnetic quantum number *m* reflects the projection of the atom's angular momentum onto the quantization axis; as the magnetic quantum number changes, the atom's equivalent magnetic moment also changes.

[0086] The excitation of the quantum state of atoms is generally achieved by irradiating the atoms with laser light; the change in the principal quantum number determines the frequency of the excitation light. For example... Figure 1 As shown, Figure 1This is a schematic diagram of the different types of quantum numbers of the atom provided in this application. There is no restriction on the change of the principal quantum number |n1-n2| (n1 is the principal quantum number of the first quantum state, and n2 is the principal quantum number of the second quantum state), but the greater the difference between |n1-n2|, the higher the frequency of the excitation light required to adjust the principal quantum number.

[0087] Taking the transition of an atom between two adjacent quantum states as an example, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the magnetic quantum number provided in this application. An atom comprises multiple quantum states, and the excitation light frequency required for a transition between two adjacent quantum states is f. i For example, the first quantum state (corresponding to the required excitation frequency f1), the second quantum state (corresponding to the required excitation frequency f2), and the third quantum state (corresponding to the required excitation frequency f3). Therefore, the difference in orbital quantum numbers |l1-l2| between two adjacent quantum states can only be 1 (l1 is the orbital quantum number of the first quantum state, and l2 is the orbital quantum number of the second quantum state), while the difference in magnetic quantum numbers is -1, 0, or 1.

[0088] like Figure 2 As shown, the polarization of the excitation light determines the magnetic quantum number of the excited state. Changing the principal quantum number of the excited state requires significant adjustment of the laser frequency, which cannot be dynamically changed in computation or simulation. However, changing the magnetic quantum number of the excited state only requires changing the polarization of the excitation light and fine-tuning the excitation light frequency on the order of 10 MHz. The polarization of the excitation light can be adjusted using a polarization electro-optic modulator, with an adjustment rate on the order of GHz. Rapid fine-tuning of the excitation light frequency can be achieved using an acousto-optic modulator (AOM), with an adjustment rate on the order of 100 MHz.

[0089] II. The ground state and Rydberg state of an atom.

[0090] Since the interatomic forces of neutral atoms in the ground state are negligible, atoms need to be excited from the ground state to the Rydberg state for information transmission. Compared to ground-state atoms, atoms in the Rydberg state have electron clouds that are several orders of magnitude larger, thus generating sufficient interatomic forces for multi-bit operations.

[0091] The strength of the interaction generally depends on the size of the electron cloud and the interatomic distance R. The size of the electron cloud is determined by the principal quantum number n of the Rydberg state, and the strength of the interatomic interaction force is proportional to n. 11 and inversely proportional to R 6 .

[0092] The ground state of an atom is the lowest energy quantum state. Since physical systems tend to occupy lower energy states, the ground state is the most stable quantum state. Due to the symmetry of atoms, atoms typically have multiple quantum states with equal energy but different orbital quantum numbers. Quantum computing generally selects two different ground states with zero orbital quantum numbers as the computational ground states, and tends to choose the ground state with zero magnetic quantum number to reduce the influence of environmental magnetic field noise on the coherence of the quantum state.

[0093] Because the electron cloud of a ground-state atom is quite small, the interatomic interaction force is almost negligible. Therefore, only single-qubit gate qubit manipulation is possible, and multi-qubit gate qubit manipulation is difficult. Thus, to perform multi-qubit logic gates or entanglement, atoms need to be excited to the Rydberg state to obtain sufficient interatomic interaction force.

[0094] Rydberg states generally refer to highly excited states with large principal quantum numbers. As the principal quantum number increases, the energy difference between adjacent energy levels decreases significantly, |E n -E n±1 |∝n -3 .

[0095] Taking rubidium (Rb) atoms as an example, Figure 3 A schematic diagram illustrating the energy difference and dipole moment of rubidium atoms provided in this application.

[0096] like Figure 3 In (A) and (B), as the principal quantum number increases, the dipole moment also increases significantly, and the energy difference between adjacent principal quantum numbers is proportional to n. -3 (|E n -E n+1 |∝n -3 The dipole moment is proportional to For example, the energy difference between principal quantum numbers n = 5 and 6 is 6 × 10⁻⁶. 5 The energy difference between n=43 and n=44 is only 100 GHz, which is a significant reduction of three orders of magnitude. The dipole moment at n=43 is approximately 400 times that at n=5.

[0097] Combining the two characteristics above, such as Figure 3 In (C), the interaction between atoms increases significantly with the principal quantum number, proportional to n. 11 For example, the intensity of the force is ∝n 11 The interatomic interaction when n=43 is approximately 3×10⁻⁶ when n=5. 15 Even for atoms trapped in optical tweezers a few micrometers apart, there are enough interactions to form multi-bit logic gates or entanglements.

[0098] In the embodiments of this application, the commonly used parameter for the interaction force strength is C6, and the commonly used Rydberg state C6 is approximately 100 GHz / (μm). 6 The Rydberg blocking effect is an essential tool for realizing two-bit logic gates. It refers to the physical phenomenon that when several atoms are all within a circle with a blocking radius, only one atom can be excited to a Rydberg state, while the excitation of other atoms is suppressed. In experiments, the Rydberg blocking effect is frequently used to add an extra phase to the quantum state of a system, thereby realizing a theoretical entanglement gate.

[0099] 3. Two-bit gate.

[0100] In quantum computing theory, single-qubit rotations and two-qubit CZ gates form the fundamental set capable of compiling any quantum circuit. A traditional π-2π-π CZ gate scheme is as follows: Figure 4 As shown, Figure 4 This application provides a schematic diagram of a CZ gate, which includes: a control atom (the atom corresponding to the control bit). Figure 4 The black pattern in the image) and a target atom (the atom corresponding to the target bit). Figure 4 (The white pattern in the image). In some alternative methods, control bits can also be called auxiliary bits, and target bits can also be called data bits.

[0101] exist Figure 4 In the provided CZ gate scheme, two addressed laser beams act on two atoms respectively. Both laser beams resonate with the transition frequencies between the atom's |1> state and Rydberg state |r> state. A π pulse is first applied to the control atom, followed by a 2π pulse applied to the target atom, and finally a π pulse applied to the control atom.

[0102] exist Figure 4 In the CZ gate scheme shown, if the two atoms are initially in the |00> state, the CZ gate does not interact with the laser, and the accumulated phase shift of the CZ gate is 0.

[0103] If two atoms are initially in the state |10>, the controlling atom experiences a total of 2π pulses and eventually returns to the state |1>. The cumulative phase of the CZ gate is π. One π pulse goes from state 1 to state r, or from state r to state 1.

[0104] If the CZ gate is initially in the |01> state, the target atom will experience a total of 2π pulses and eventually return to the |1> state. The cumulative phase of the CZ gate is π.

[0105] If the CZ gate is initially in the |11> state, the control atom experiences a total of 2π pulses and eventually returns to the |1> state, with a cumulative phase of π. The target atom, on the other hand, is excited to the |r> state after the control atom is excited after the first π pulse. The blocking effect generated by the control atom in the |r> state prevents the target atom from coupling with the laser and undergoing a transition. Therefore, in this case, the cumulative phase of the CZ gate is also π.

[0106] In this scheme, the evolution matrix of the two-bit gate with {|00>,|01,|10>,|11>} as the ground state is Diag{1,-1,-1,-1}, which is the same as the theoretically defined CZ gate.

[0107] In the atomic ensemble provided in this application embodiment, atoms located in different layers can serve as data bits and auxiliary bits, respectively. Data bits can be represented by physical bits or logical bits, while auxiliary bits can be used for data bit detection and information storage. By performing Rydberg excitations on the data bits and auxiliary bits, interatomic interactions are generated between them, thereby transferring the quantum state of the data bit to a specific auxiliary bit, achieving low-crosstalk information transmission between different quantum bits. During information transmission, specific atom pairs must be selected for Rydberg multi-bit operations to ensure that information is transmitted only between specific atoms, avoiding crosstalk between neighboring atoms.

[0108] In this context, a physical bit refers to the physical carrier of a quantum bit, which can be an ion, an atom, a photon, etc. A logical bit is composed of multiple physical bits. Quantum information is encoded in a specific coding form, and the encoded information is used to determine the logical bits in order to avoid the quantum information represented by the logical bits being affected by noise.

[0109] In conventional techniques, quantum computing systems irradiate and control selected atoms with a highly focused beam of light. However, the highly focused optical tweezers light is significantly detuned to the atomic transition frequencies. Therefore, to reduce the heating and decoherence of the atoms by the optical tweezers light, the atoms in the vacuum glass cavity are moved independently by AOD. That is, AOD needs to move and load each atom in the vacuum glass cavity serially. As the size of the qubit array increases, the number of atom movements and the distance of atom movement performed by AOD increase significantly. The loading time of the qubit array is long and the efficiency of atom loading is low.

[0110] In order to at least solve the above problems, the atomic systems and atomic arrangement methods applicable to the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0111] Figure 5 A schematic diagram of the structure of an atomic system provided in this application Figure 1The atomic system 400 includes: an atomic source 410, an atomic cavity 420, a first optical module 431, a second optical module 432, and a quantum bit measurement unit 450. The atomic cavity 420 is connected to the atomic source 410.

[0112] Optionally, the atomic system 400 may further include a hardware control and timing system 401, such as a controller and a memory. This memory may include, but is not limited to, the following types of storage media: random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage media known in the art.

[0113] The controller can be used to control various components in the atomic system 400 according to the information to be calculated. For example, the controller can refer to a processor, such as a central processing unit (CPU), an application-specific integrated circuit (ASIC), or a programmable logic device (PLD). The PLD can be a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. Alternatively, the processor can also be a digital signal processor (DSP) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. In this embodiment, the controller can be a microprocessor or any conventional processor.

[0114] The atomic arrangement method provided in this embodiment may include the following steps: an atomic source 410 provides multiple atoms to an atomic cavity 420, and the atomic cavity 420 stores the atoms provided by the atomic source 410. A first optical module 431 generates multiple optical tweezers in the atomic cavity 420, and arranges the multiple optical tweezers according to first information to obtain a first atomic array; a second optical module 432 emits internal state-dependent array light into the atomic cavity 420, causing the first atomic array to rearrange to obtain a second atomic array. The arrangement relationship and rearrangement process of each atom in the first and second atomic arrays can be referred to the following... Figure 6 , Figures 16 to 19 The relevant descriptions will not be repeated here.

[0115] Atom source 410 is used to provide multiple atoms. These multiple atoms can refer to atoms of the same type. For example, the atoms provided by atom source 410 can include, but are not limited to, the following types of atoms: alkali metal atoms such as lithium, sodium, potassium, rubidium, ytterbium, and cesium; or alkaline earth metal atoms such as beryllium, magnesium, calcium, strontium, barium, and radium. The difference between alkali metal atoms and alkaline earth metal atoms is that alkali metal atoms all have one outermost electron belonging to the s orbital, while alkaline earth metal atoms all have two outermost electrons belonging to the s orbital.

[0116] As an alternative implementation, the atomic cavity 420 includes a glass cavity and a vacuum structure.

[0117] For example, the glass cavity is capable of withstanding a vacuum environment within its cavity. For instance, the glass cavity includes a first connector and a cavity structure. For example, the vacuum structure may refer to a vacuum pump or other components or devices used to generate a vacuum environment, and this application is not limited thereto.

[0118] As a possible specific example, the aforementioned glass cavity includes: a first connector and a cavity structure, the first connector being detachably connected to the vacuum structure and the first hole structure. The first connector is connected to the atomic source 410, and the cavity structure is provided with the first hole structure. For example, the first hole structure penetrates both the inner and outer walls of the cavity structure.

[0119] For example, if the cavity structure is connected to a vacuum structure via a first hole structure, the vacuum structure is used to extract background gas molecules from the cavity structure to maintain a vacuum state. In this example, the center of the atomic system 400 can be a vacuum glass cavity connected to a vacuum pump to maintain an ultra-high vacuum environment in the glass cavity, thereby suppressing collisions between atomic qubits and background gas molecules in the cavity and increasing the trapping time and coherence time of atoms in the atomic cavity 420. An atomic source 410 is also provided in the vacuum system to supply atoms used by the atomic system.

[0120] The glass cavity and vacuum structure described above are merely possible implementations of the atomic cavity 420 provided in this embodiment and should not be construed as limiting this application. In other optional implementations, the glass cavity in the atomic cavity 420 may also be replaced with other cavities capable of maintaining a vacuum environment within their cavity, and this application does not limit this.

[0121] In this embodiment, the atomic cavity 420 is used to store atoms provided by the atomic source 410, which includes multiple atoms of the same type.

[0122] The following section provides an exemplary description of the loading methods of the atomic array in the atomic cavity 420, using different optical modules as examples.

[0123] Please see Figure 5 The first optical module 431 is used to: generate multiple optical tweezers in the atomic cavity 420, and arrange the optical tweezers that have captured atoms in the atomic cavity 420 according to the first information to obtain a first atomic array.

[0124] In one feasible example, the first information is the input information of the quantum computing process. Thus, the atomic arrangement method provided in this application embodiment can be applied to quantum computing scenarios or large-scale quantum simulation scenarios.

[0125] In another feasible example, the first information is the adjustment information for the quantum error correction process. Thus, the atomic arrangement method provided in this application embodiment can be applied to error correction processes in quantum computing scenarios or large-scale quantum simulation scenarios, or other scenarios requiring quantum error correction.

[0126] The two feasible examples above are only optional contents of the first information provided in the embodiments of this application. Depending on the specific scenario in which the atomic system 400 is applied, the first information may also be used to indicate other contents, and this application does not limit it.

[0127] In this embodiment, the first optical module 431 may include, but is not limited to, one or two of the following: a light source, a spatial light modulator (SLM), or an acousto-optic deflector (AOD). The light source is used to provide trapped light or a trapped beam, and the SLM and AOD are used to generate an optical tweezers array based on the beam provided by the light source.

[0128] It is worth noting that since the optical tweezers generated by the first optical module 431 are used to trap atoms, in some examples, the beams that form optical tweezers can also be called static optical tweezers array beams in the quantum computing process, and the first optical module 431 can also be called an optical tweezers unit or optical tweezers module, etc.

[0129] In this embodiment, the optical tweezers generated by the first optical module 431 include a plurality of first optical tweezers and a plurality of second optical tweezers. The first optical tweezers are used to probabilistically trap individual atoms, and the second optical tweezers are used to deterministically trap an ensemble of atoms. The ensemble of atoms includes multiple atoms simultaneously trapped by the same optical tweezers.

[0130] like Figure 6 As shown, Figure 6 This is a schematic diagram of the arrangement of the atomic array provided in this application. Figure 6 In the first optical module 431, the multiple first optical tweezers and multiple second optical tweezers generated have a one-to-one correspondence, that is, the first optical tweezers and the second optical tweezers are paired one-to-one. For example Figure 6 The content shown in ① is the pairing of the first and second optical tweezers, circled by the dashed box corresponding to ①; and so on. Figure 6 The contents shown in ② are the first and second optical tweezers paired together, circled in the dashed box corresponding to ②. Figure 6 The other optical tweezers shown are the same as those shown in ① and ②, and will not be described in detail here.

[0131] The following description uses an example of a first atomic array comprising N first optical tweezers and N second optical tweezers to illustrate the contents of the first atomic array. This first atomic array includes a first layer and a second layer in a first region. The first layer includes N first optical tweezers, and the second layer includes N second optical tweezers. Each first optical tweezer is used to capture one atom, and each second optical tweezer is used to capture an ensemble of atoms. The first layer includes M atoms, and the second layer includes N ensembles of atoms, where N ≥ M.

[0132] Please see Figure 6 , Figure 6 The first optical tweezers is represented by a solid white circle, and the second optical tweezers by a dashed white circle. And, in Figure 6 In this context, N=9, meaning the first layer includes 9 first optical tweezers and the second layer includes 9 second optical tweezers. Furthermore, the first layer includes 7 atoms (M=7) and the second layer includes 9 sets of atomic systems (N=9).

[0133] Please see Figure 6 In the first atomic array, at positions ① and ②, the first optical tweezers failed to capture atoms. Therefore, this first atomic array can also be referred to as a defective atomic array. In some optional cases, the atomic array described in the embodiments of this application may also be referred to as a quantum array, a quantum bit array, or other names, and this application does not limit this.

[0134] In this embodiment of the application, in order to more accurately manipulate different atoms in the atomic cavity, optical tweezers with different wavelength ranges can be used to capture and manipulate different types of atoms. For example, Figure 6The first and second optical tweezers have different wavelengths. The first optical tweezers, operating in a first wavelength range, are used to capture single atoms, while the second optical tweezers, operating in a second wavelength range, are used to capture atomic ensembles. In the embodiments of this application, during the loading and rearrangement stage of the atomic array, optical tweezers of different wavelengths are used to arrange single atoms and atomic ensembles separately, so that the arranged atomic array meets the requirements of quantum computing.

[0135] Thus, using different optical tweezers within different wavelength ranges avoids the problem of disordered atomic array arrangement caused by using optical tweezers of the same wavelength to capture atoms, which is beneficial to improving the accuracy of quantum computing. Moreover, using different optical tweezers to capture atoms avoids the problem of crosstalk between single atoms and atomic ensembles, which is beneficial to improving the fidelity of atomic arrays and the accuracy of quantum computing.

[0136] It is worth noting that, since the first and second layers contain the same type of atoms, when multiple optical tweezers overlap in space, there may be overlap between different tweezers. To avoid the problem of poor accuracy caused by tweezer overlap, the paired first and second optical tweezers can have a certain spatial offset. The offset setting between the first and second optical tweezers will be discussed below. Figure 7 Two possible arrangements are provided.

[0137] like Figure 7 As shown, Figure 7 This is a schematic diagram of the arrangement of optical tweezers in the atomic array provided in this application. Since the first optical tweezer is used to capture single atoms, it is also called a single-atom optical tweezer, and the waist of the first optical tweezer is about 1 μm. Since the second optical tweezer is used to capture atomic ensembles, it is also called an atomic ensemble optical tweezer, and the waist of the second optical tweezer is about 2 μm. The number of atoms in the atomic ensemble that the second optical tweezer can capture is related to the size of the waist, such as 100 atoms or other values.

[0138] exist Figure 7 In the illustrated two-dimensional arrangement, the first optical tweezers in the first layer and the second optical tweezers in the second layer are located on the same plane, and the paired first and second optical tweezers have a second bias value, such as... Figure 7 As shown in (1) to (4) in the diagram. The second bias value may be 10 micrometers (μm), 12 μm, 15 μm or other values. The second bias value may be determined based on the atom type, the precision of the quantum computing or other information, which is not limited in this application.

[0139] Two optical tweezers arrays are placed on the same horizontal plane, and single-atom-to-atom ensemble or single-atom-to-single-atom interactions are achieved through independent well depth control, rapid two-dimensional movement, and adjustment of the blocking radius. For example... Figure 7The illustrated two-dimensional arrangement scheme allows for suitable internal state control by moving the single-atom array (first layer) closer and adjusting the well depth, enabling resonance between the atomic ensemble and the manipulation light for single-atom-to-atom ensemble multi-bit operations. Conversely, the atomic ensemble can be prepared to an internal state that does not resonate with the Rydberg light and moved away from the single atom for single-atom-to-single-atom operations.

[0140] by Figure 7 Taking (1) as an example, in the case where the first optical tweezers / single-atom optical tweezers in (1) captures an atom and the second optical tweezers / atomic ensemble optical tweezers in (1) capture a set of atomic ensemble optical tweezers, the atom in the first layer and the set of atomic ensembles in the second layer that are paired with the atom have the aforementioned second bias value.

[0141] exist Figure 7 In the illustrated three-dimensional arrangement, the first layer and the second layer are located in different planes, and the first optical tweezers in the first layer and the second optical tweezers in the second layer that are paired with the first optical tweezers have a first bias value along a first direction, which is perpendicular to the first layer and the second layer. Figure 7 As shown in (5) to (8) in the figure. The first bias value may be determined based on the type of atom, the precision of the quantum computing or other information, which is not limited in this application.

[0142] Single-atom arrays and atomic ensemble arrays are biased in the z-direction by spatial light modulators (SLMs) or other optical components, so that the single atoms (data bits) and atomic ensembles (auxiliary bits) are located in different planes, such as... Figure 7 The three-dimensional arrangement scheme is shown. Simultaneously, it can be biased in a direction perpendicular to the xy plane (first layer or second layer) (first direction) to reduce crosstalk between optical tweezer arrays in the vertical direction (first direction). When performing single-atom-atom ensemble multi-bit operations, this can be achieved through directional Rydberg interactions to reduce crosstalk between atoms.

[0143] by Figure 7 Taking (5) as an example, in the case where the first optical tweezers / single-atom optical tweezers in (5) captures an atom and the second optical tweezers / atomic ensemble optical tweezers in (5) capture a set of atomic ensemble optical tweezers, the atom in the first layer and the set of atomic ensembles in the second layer that are paired with the atom have the aforementioned first bias value along the first direction.

[0144] above Figure 7 The two-dimensional and three-dimensional arrangements shown are only optional arrangements provided by the embodiments of this application and should not be construed as limiting the first atomic array and the second atomic array provided by this application. Depending on the needs of quantum computing or quantum error correction, the arrangement of different layers in the atomic array may also change, and this application does not limit this.

[0145] It is worth noting that the first optical module 431 may include one or more light sources, and the first optical tweezers and the second optical tweezers may be emitted by different optical emitters, such as the optical emitters may include, but are not limited to, the aforementioned AOD or SLM or others.

[0146] This application uses a three-dimensional arrangement between the first and second layers of an atomic array as an example for illustration, combined with... Figure 6 Taking the first atomic array as an example, the success rate of the first optical tweezers in capturing a single atom is not 100%, but rather there is a certain probability of failure (e.g., Figure 6 The first atomic array includes ① and ②). Therefore, the second optical module 432 in the atomic system 400 also needs to rearrange the first atomic array so that the information represented by the rearranged second atomic array matches the first information.

[0147] Please continue reading Figure 5 The second optical module 432 in the atomic system 400 is used to emit internal state dependent array light into the atomic cavity 420, so that the first atomic array is rearranged to obtain the second atomic array.

[0148] In the second atomic array, the first layer includes N atoms, which include M atoms and NM atoms in the first layer whose internal state depends on the array light moving from the NM group of atoms in the atomic ensemble. One atom in the N atoms is used to characterize a physical bit.

[0149] like Figure 6 The second atomic array in the array has N=9 and M=7. The first layer includes 9 atoms, of which 7 atoms are atoms already loaded in the first atomic array and 2 atoms are atoms that have moved from the second layer ensemble to the first layer.

[0150] In the second atomic array, the second layer includes N atomic ensembles, and one of the N atomic ensembles is used to characterize the auxiliary bit paired with a physical bit. For example... Figure 6 The second atomic array, N=9, consists of 9 atomic ensembles, of which 7 atoms are atoms already loaded in the first atomic array and 2 atoms are atoms that have moved from the second atomic ensemble to the first layer.

[0151] Optionally, in the second atomic array, for the first atom among the NM atoms contained in the first layer, which is moved from the first atomic ensemble in the second layer to the first layer after being irradiated by the internal state dependent array light, the first optical tweezers for capturing the first atom are paired with the second optical tweezers for capturing the first atomic ensemble.

[0152] like Figure 6In ①, in the second atomic array, the atom captured by the first optical tweezers in ① is moved from the atomic ensemble captured by the second optical tweezers in ① to the first layer.

[0153] like Figure 6 In ②, in the second atomic array, the atom captured by the first optical tweezers in ② moves from the atomic ensemble captured by the second optical tweezers in ② to the first layer.

[0154] It is worth noting that in the atomic cavity 420, atoms can move from the second layer to the first layer without fluorescence imaging, and the paths of atomic movement are fixed. Different atoms can move in parallel after being irradiated by the internal state-dependent array light. For details on the principle, please refer to the following. Figures 16 to 19 The description.

[0155] In the rearranged second atomic array, the physical bits represented by the N atoms in the first layer match the first information, and the number of atoms in the first atomic array is the same as the number of atoms in the second atomic array. The atomic system 400 does not need to move atoms from regions outside the first region to fill the first optical tweezers that failed to capture atoms in the first atomic array, and the time for atomic movement is reduced.

[0156] Combination Figures 5 to 7 As can be seen from the embodiments, the atomic system 400 uses paired first optical tweezers and second optical tweezers to capture atoms, such that the single atoms captured by each first optical tweezer are bound to the first layer of the atomic array, and the atomic ensembles captured by each second optical tweezer are bound to the second layer of the atomic array. Since there is a certain failure probability in the process of the first optical tweezers capturing single atoms, some of the first optical tweezers in the first layer fail to capture single atoms. Therefore, the atomic system 400 uses internal state-dependent array light to rearrange the initially loaded first atomic array, moving atoms from the atomic ensembles in the second layer to the first layer, thereby successfully loading the physical bits matching the first information into multiple first optical tweezers.

[0157] During the rearrangement of the atomic array, the internal state dependent array light can move multiple atoms in the second layer in parallel (such as the NM atoms mentioned above), so that the physical bits represented by the rearranged atomic array match the first information. The internal state dependent array light does not need to move atoms one by one from outside the atomic array, nor does it need to fill the first optical tweezers in the first atomic array that have not captured atoms in sequence, thus solving the problems of long loading time and low efficiency of atomic loading of quantum bit arrays.

[0158] After the atomic array is arranged, the atomic system 400 can also illuminate the second atomic array with global light to realize the quantum computing process. Figure 5 Based on this, embodiments of this application provide another atomic system, such as Figure 8 As shown, Figure 8A schematic diagram of the structure of an atomic system provided in this application Figure 2 . Figure 8 Different from Figure 5 The point is: Figure 8 The atomic system 400 also includes a third optical module 433.

[0159] The third optical module 433 is used to generate global light according to the second information, which is used to irradiate the second atomic array. In some optional cases, the third optical module 433 may also be called a global optical module or a global optical unit, etc. Regarding the specific implementation of the global light, the following example is taken with the global light including a first polarized beam and a second polarized beam. The embodiments of this application provide a possible example: the third optical module 433 generates a first polarized beam in a first direction and a second polarized beam in a second direction according to the second information, and irradiates the aforementioned second atomic array with the first polarized beam and the second polarized beam.

[0160] The first frequency and first direction of the first polarized beam correspond to either a first Rydberg state or a second Rydberg state. For example, the first polarized beam is used to excite a single atom in the first layer of the second atomic array to either a first or second Rydberg state. For instance, when a single atom is in its ground state, irradiating it with the first polarized beam changes the quantum state of the single atom to either a first or second Rydberg state.

[0161] The second frequency and second direction of the second polarized beam correspond to either a third or fourth Rydberg state. For example, this second polarized beam is used to excite the atomic ensemble of the second layer in the second atomic array to a third or fourth Rydberg state. For instance, when the atomic ensemble is in its ground state, irradiating it with the second polarized beam changes the quantum state of the atomic ensemble to a third or fourth Rydberg state.

[0162] In quantum computing scenarios, the purity of beam polarization significantly impacts the fidelity of qubit logic gates. Therefore, a suitable angle is needed between the two optical paths (the first polarized beam and the second polarized beam) to improve the fidelity of the qubit logic gates represented by the atomic array in the atomic cavity 420. For example, the angle between these two optical paths can be determined based on the confidence level requirements of the quantum computing. A higher confidence level requires a larger angle, while a lower confidence level requires a smaller angle.

[0163] As one possible example, the angle between the first and second polarized beams is 90°. In quantum computing, by changing the angle between the two polarized beams, the Rydberg states of the atoms corresponding to the polarized beams can be manipulated, allowing the atomic array to represent different qubits.

[0164] Regarding the process of generating and adjusting polarized beams, in Figure 8 Based on the third optical module 433 shown, this application embodiment provides a possible implementation method, such as... Figure 9 As shown, Figure 9 A schematic diagram of the structure of an atomic system provided in this application Figure 3 The third optical module 433 includes an excitation light source 433a and an optical path modulation component 433b, which are connected together.

[0165] Among them, the excitation light source 433a is used to generate an irradiation beam that irradiates the atomic array in the atomic cavity 420.

[0166] The optical path modulation component 433b is used to process the optical parameters of the irradiating beam according to the second information to obtain a first polarized beam in a first direction and a second polarized beam in a second direction. The optical parameters include one or more of the following: beam direction, polarization, and frequency. The beam direction indicates the physical direction of the optical path during beam propagation. For a description of polarization and frequency, please refer to the technical terminology in the specific embodiments; it will not be repeated here.

[0167] The optical path modulation component 433b can be implemented in one or more different ways to control the optical parameters of the illuminating beam. The following section combines... Figure 10 It provides three possible implementations of the optical path modulation component 433b. Figure 10 This is a schematic diagram illustrating the implementation of the optical path modulation component provided in this application.

[0168] The first implementation method ( Figure 10 In method 1), the optical path modulation component 433b includes a beam splitter and an acousto-optic modulator (AOM). The AOM is used to divide the illumination beam into a first beam of a first frequency and a second beam of a second frequency. The beam splitter is used to adjust the direction of the first beam to a first direction to obtain a first polarized beam and adjust the direction of the second beam to a second direction to obtain a second polarized beam.

[0169] In one possible scenario, the AOM described above can also be replaced by AOD or other optical devices that can be used to adjust the frequency and polarization. During beam adjustment, the order of beam direction and frequency adjustment can also change; for example, the frequency of the irradiated beam can be adjusted first by the AOD, and then the beam direction can be adjusted by the beam splitter. That is, in the embodiments of this application, the order of adjustment of each optical parameter can be changed according to the physical location of the optical path modulation component in the atomic system or the priority of the optical parameters in the optical path (manual setting or system default), and this application does not limit this.

[0170] In this way, by using an AOM to adjust the frequency of the beam and a beam splitter to adjust the incident angle (beam direction) of the beam, the two polarized beams can be used to manipulate the quantum state of atoms, so that each atom in the atomic array is excited to a different Rydberg state, thereby controlling the interatomic interaction force between different atoms in the atomic array, realizing the opening or closing of the quantum bit logic gate, and completing the quantum computing process.

[0171] Furthermore, since the embodiments of this application select suitable combinations of Rydberg states, the frequency range of the light required to change the magnetic quantum number of the atom is small. Therefore, the frequency range of the light required to control the transition between Rydberg states of the atom system is reduced. Using AOM or AOD can also meet the requirement of rapidly adjusting the frequency range of the light beam, which is beneficial for rapidly adjusting the quantum state of the atom array to improve the speed and efficiency of quantum computing.

[0172] The second implementation method ( Figure 10 In method 2), the optical path modulation component 433b includes an electro-optic modulator (EOM) and a polarizing beam splitter (PBS), also known as a polarizing beam splitter prism. The EOM processes the illumination beam to obtain a first and a second illumination sub-beam with different polarizations. The PBS adjusts the direction of the first illumination sub-beam to a first direction to obtain a first polarized beam, and adjusts the direction of the second illumination sub-beam to a second direction to obtain a second polarized beam.

[0173] Thus, embodiments of this application provide two non-isotropic excitation light paths (a first polarized beam and a second polarized beam). By using an optical path modulation component to change the beam direction, polarization, and frequency, the transitions of atoms between different Rydberg states can be controlled, causing changes in the magnetic quantum number of a single atom or an atomic ensemble, which is beneficial for realizing quantum computing processes based on qubits.

[0174] The third implementation method ( Figure 10In method 3), the optical path modulation component 433b includes a digital micromirror device (DMD). This DMD is used to: determine the optical parameters to be used based on the second information, and process the irradiated beam according to the optical parameters to obtain a first polarized beam and a second polarized beam. The DMD is a type of optical switch, utilizing a rotating mirror to achieve the opening and closing of the optical switch, with an opening and closing time on the order of microseconds. The working principle of the DMD includes: when the light beam is directed towards the reflector of the DMD and the DMD is open, the light beam can enter one end of the optical fiber through a symmetrical optical path; when the DMD is closed, i.e., the reflector of the DMD undergoes a small rotation, the light beam is reflected and transmitted in another direction. If the optical path in that other direction is closed, the optical switch is closed.

[0175] The above three implementation methods are merely examples of optical path modulation components provided in the embodiments of this application and should not be construed as limiting this application. For example, the device used for beam splitting is not limited to a beam splitter, PBS, or DMD, but can also be other fast beam splitting components capable of achieving beam splitting functionality. In some optional situations, the above three implementation methods can be used selectively, or partially or in combination.

[0176] Regarding the optical path of the illuminating beam, assuming the above three implementation methods are used in combination, in Figure 10 Based on this, the embodiments of this application provide a possible example where the frequency of the beam can be rapidly modulated by the radio frequency signal of the AOM or EOM; the polarization adjustment of the beam requires changing the incident direction of the beam through a fast beam splitting component, such as the angle between two polarized beams being 90°.

[0177] In this embodiment, the modulation of interatomic interactions requires rapidly changing the Rydberg states of atoms. This is achieved by rapidly adjusting the frequency, direction, and polarization of the laser beam. Rapid adjustment of the laser frequency can be accomplished by controlling the radio frequency signals of the AOM or EOM, while adjusting the polarization of the excitation light requires changing the incident direction of the excitation light. Since the frequency required to change the magnetic quantum number (100MHz) is much smaller than the frequency required to change the principal quantum number (10GHz), the adjustment of the quantum number is shortened from the millisecond level to the nanosecond level, effectively improving the modulation rate of interatomic interactions and thus enhancing the efficiency of quantum computing.

[0178] In quantum computing, the polarization of the light beam and its direction of travel are also related to the angle of the quantization axis in the atomic cavity 420. The direction of the quantization axis is determined by the magnetic field generated by the coils wound around the atomic cavity 420. Therefore, in order to improve the strong directionality of the interatomic interaction force, the quantization axis can be adjusted by adjusting the magnitude and direction of the magnetic field, thereby changing the direction of the interatomic interaction in the atomic array.

[0179] To further enhance the strong directionality of the interatomic interaction forces in the atomic array, embodiments of this application can also enhance the single dipole moment force by controlling the orbital quantum number.

[0180] Let's combine the following... Figure 11 The relevant content will be illustrated by example regarding the action of dipole moment forces. Figure 11 This is a schematic diagram illustrating the three types of interatomic interactions provided in this application. Based on the quantum properties of atoms, it is known that the strength of interatomic interactions varies with the angle of the quantization axis in many different ways.

[0181] exist Figure 11 In Example 1 shown, the force along the vertical direction is larger, while the force along the horizontal direction is smaller. That is, the dipole force along the vertical direction is strong, and the interatomic interaction force has a strong directionality along the vertical direction.

[0182] exist Figure 11 In Example 2 shown, there is no force in the up-down direction, but the force in the left-right direction is relatively large. That is, the dipole force in the left-right direction is strong, and the interatomic interaction force has a strong directionality in the left-right direction.

[0183] exist Figure 11 In Example 3 shown, the forces along the lower left-upper right direction are relatively large, and the forces along the upper left-lower right direction are also relatively large. That is, the interatomic interaction forces have strong directionality in the lower left-upper right and upper left-lower right directions.

[0184] The above three examples, which implement the methods provided in this embodiment, should not be construed as limiting this application. In general, Figure 11 The three types of interatomic forces shown mix together, causing the interatomic forces in the atomic array to lose their strong directionality.

[0185] To enable strong directionality of interatomic interactions and thus effectively control interatomic interactions in different directions, embodiments of this application provide an optional implementation method: selecting an appropriate orbital quantum number to break the spatial symmetry of transitions between adjacent Rydberg states, thereby strengthening the directionality of interatomic interactions and improving the accuracy of quantum computing.

[0186] The embodiments of this application select the following three possible ways to implement the orbital quantum number.

[0187] In the first possible scenario, the orbital quantum number of the first atom corresponding to the first and second Rydberg states is not zero. Thus, the first atom possesses a unidirectional dipole moment force within the atomic array, such as... Figure 11 Example 1 or Example 2 in the document. It should be understood that the single direction is not limited to the up-down or left-right direction, but can be other directions, which are not limited in this application.

[0188] In the second possible scenario, the orbital quantum numbers of the second atom corresponding to the third and fourth Rydberg states are not zero. Thus, the second atom possesses a unidirectional dipole moment force within the atomic array, such as... Figure 11 Example 1 or Example 2 in the document. It should be understood that the single direction is not limited to the up-down or left-right direction, but can be other directions, which are not limited in this application.

[0189] In the third possible case, the orbital quantum number of the first atom corresponding to the first and second Rydberg states is not zero, and the orbital quantum number of the second atom corresponding to the third and fourth Rydberg states is not zero.

[0190] As an optional implementation, in the second atomic array provided in the above embodiments, the interatomic interaction force between single atoms is less than the interatomic interaction force between single atoms and atomic ensembles. Thus, the interaction strength between single atoms and atomic ensembles varies by orders of magnitude with the angle, enabling the effect of turning on or off qubit logic gates in specific directions.

[0191] In one possible specific example, an atomic system can make the interaction force between single atoms much smaller than the interaction force between single atoms and atomic ensembles by choosing the quantum state (Rydberg state) or the spatial arrangement of atoms (the arrangement of the atomic array), thereby effectively closing the logic gate between single atoms, so as to realize the opening or closing of the quantum bit logic gate in a specific direction.

[0192] The above combination Figure 9 and Figure 11 The specific implementation of the global light and the third light module 433 is illustrated below. Figure 8 The quantum bit measurement unit 450 provided in the embodiments of this application will be described.

[0193] The qubit measurement unit 450 is used to: collect the scattered photons generated in the second atomic array after being irradiated by the probe beam, and determine the quantum computing result between the first information and the second information based on the scattered photons.

[0194] Regarding the implementation of the qubit measurement unit 450, in Figure 8 An optional example is provided based on this, such as Figure 12 As shown, Figure 12 A schematic diagram of the structure of an atomic system provided in this application Figure 4 The components already present in the aforementioned embodiments will not be described again here. Figure 12 The quantum bit measurement unit 450 includes: an atomic detection light source 451, an objective lens 452, a photoelectric conversion unit 453, and a bit quantization unit 454. The photoelectric conversion unit 453 is connected to the objective lens 452, and the bit quantization unit 454 is connected to the photoelectric conversion unit 453.

[0195] The atomic detection light source 451 is used to provide a detection beam that illuminates the second atomic array. In some possible cases, this detection beam may also be referred to as the detection beam for qubits.

[0196] Objective 452 is used to collect scattered photons generated after the second atomic array is illuminated by a probe beam. Figure 12 In this embodiment, the quantum bit measurement unit 450 includes two objective lenses 452. However, this is only an example provided in this embodiment and should not be construed as a limitation of this application. The quantum bit measurement unit 450 may also include only one objective lens or include more objective lenses to collect the scattered photons mentioned above.

[0197] The photoelectric conversion unit 453 is used to: convert the scattered photons collected by the objective lens 452 into an electrical signal, which indicates the qubits in the atomic array, such as voltage or current. In some possible cases, the photoelectric conversion unit 453 may include a camera and a photoelectric signal processing module. For example, the camera is used to perform fluorescence imaging on the scattered photons collected by the objective lens 452 and output image data; the photoelectric signal processing module is used to process the image data output by the camera to obtain an electrical signal characterizing the qubits. The camera and the photoelectric signal processing module can be two interconnected hardware devices or integrated on a single hardware device; this application does not limit this.

[0198] The bit quantization unit 454 is used to determine the quantum computation results of the first and second information based on the electrical signal.

[0199] It is worth noting that if the interatomic interaction characteristic of a qubit is less than a set threshold, the logic gate of that qubit is indicated to be closed; if the interatomic interaction characteristic of a qubit is greater than the set threshold, the logic gate of that qubit is indicated to be open. It is also worth noting that if the interatomic interaction characteristic of a qubit is equal to the set threshold, the logic gate of that qubit is indicated to be either open or closed. Whether it is open or closed can be determined according to the needs of quantum computing, and this application does not limit this.

[0200] Combination Figures 8 to 12 As can be seen from the provided embodiments, during the atomic arrangement process, the atomic system 400 uses the second optical module 432 to emit internal state dependent array light to rearrange the atomic array. During the rearrangement process, multiple atoms can be moved in parallel, so that the physical bits represented by the rearranged atomic array match the first information, reducing the arrangement time of the atomic array, which is beneficial to reducing the latency of quantum computing and improving the efficiency of quantum computing.

[0201] The beneficial effects of the atomic arrangement method provided in the embodiments of this application and the rearrangement principle of the atomic array will be further explained below with reference to the accompanying drawings.

[0202] Figure 13 This is a flowchart illustrating a quantum computing method, which includes the following four processes: (i) magneto-optical trap fabrication and cooling; (ii) optical tweezers array loading and rearrangement; (iii) quantum state preparation and manipulation; and (iv) quantum state readout. The above four processes are illustrated below with reference to the accompanying drawings.

[0203] (I) Fabrication and cooling of magneto-optical trap.

[0204] Please see Figure 13 , Figure 13 (1) in the text refers to the preparation of atomic groups (or atomic clouds). Figure 13 (2) is an optical tweezers array. Figure 13 (3) involves randomly loading atoms from atomic clusters (or atomic clouds) into an optical tweezers array. The following section combines... Figure 14 An exemplary illustration is provided of the loading of optical tweezers and atomic arrays.

[0205] Figure 14 This is a schematic diagram illustrating the loading of the optical tweezers and atomic array provided in this application. Figure 14 In (a), multiple atoms stored in the atomic cavity form an atomic cloud. The atoms in the atomic cloud are cooled by a laser and collected at the center of the atomic cavity's magnetic field. Simultaneously, the atomic cavity also includes multiple optical tweezers generated by the first optical module 431. These optical tweezers form a structure as shown in the diagram. Figure 14 The optical trap shown in (b) is an example. Figure 14In (b), the optical trap corresponds to a 3×3 optical tweezers array, meaning the atomic cavity includes nine first optical tweezers for capturing atoms. Similarly, the atomic system 400 can also control the first optical module 431 to generate nine second optical tweezers for capturing the atomic ensemble.

[0206] Because this optical tweezers array is used to capture atomic clouds located at the center of a magnetic field, in some cases, the optical trap is also called an atomic magneto-optical trap or magneto-optical trap in an atomic cavity.

[0207] In the embodiments of this application, each optical tweezer can be used to capture one or more atoms. For example, the first optical tweezer described above is used to capture one atom, and the second optical tweezer described above is used to capture multiple atoms, such as two, three, five, 100, or other numbers. The number of atoms that each optical tweezer can capture is related to the atomic spatial density and the spatial range that the optical tweezer can cover.

[0208] The following is combined Figure 14 (c) in the example illustrates the process of the first optical tweezers capturing a single atom (loading and rearranging of the atom array).

[0209] (ii) Loading and rearrangement of optical tweezer array.

[0210] Please see Figure 13 , Figure 13 (4) in the figure is fluorescence imaging of a randomly loaded atom array. Figure 13 (5) in the figure represents the determination of atoms and the calculation of the path of atom movement based on the structure of fluorescence imaging. Figure 13 (6) in the diagram refers to moving atoms one by one based on the path calculation results. The following section combines... Figure 14 An exemplary illustration is provided of the loading and rearrangement process of the optical tweezers array.

[0211] like Figure 14 As shown in (c), due to the randomness of the process of loading atoms using optical tweezers, only some of the optical tweezers in the magneto-optical trap (optical trap) may be loaded with atoms, resulting in a random distribution of the atoms in the atomic array. In order for the atoms in the atomic cavity to meet the requirements of quantum computing, the atoms in the atomic cavity need to be rearranged according to the computational problems to be solved by quantum computing (such as quantum simulation, data computation, etc.).

[0212] Optionally, the hardware control and timing system 401 in the atomic system can determine the arrangement of each atom in the atomic cavity based on the input information to be calculated.

[0213] For example, the input information to be calculated includes first information and second information. The first information is used to determine the arrangement of the first optical tweezers that have trapped a single atom in the atomic cavity, and the second information is used to determine the optical parameters (such as beam direction, frequency, and polarization) of the excitation light required to manipulate the quantum state.

[0214] In some possible approaches, the first piece of information is determined based on the target problem that the atomic system is to solve. A suitable atomic array arrangement and qubit logic gates (or simply quantum gates or logic gates) are designed according to the target problem. The atomic array arrangement is used to determine the first piece of information, and the qubit logic gates are used to determine the combination of quantum numbers (principal quantum number, orbital quantum number, and magnetic quantum number) to be used in this embodiment.

[0215] Optionally, the amount of data in the first information is related to the bit width of the qubits that the atomic array can represent. For example, the bit width of the qubits that the atomic array can represent is greater than or equal to the amount of data in the first information.

[0216] In the first optional scenario, the bit width of the qubits represented by the atomic array is greater than the data size of the first information. For example, if the bit width of the qubits represented by the atomic array is 10 bits, then the data size of the first information is 9 bits, 8 bits (1 byte), or other values.

[0217] In the second alternative scenario, the bit width of the qubits that the atomic array can represent is equal to the amount of data in the first information. For example, if the bit width of the qubits that the atomic array can represent is 10 bits, then the amount of data in the first information is 10 bits.

[0218] The two possible scenarios described above are merely examples of the bit width of the qubits that can be characterized by the atomic array provided in this embodiment, and should not be construed as limiting this application. In some optional scenarios, an atomic array can be used to characterize qubits with smaller or larger bit widths, such as 4-bit, 2-bit, etc. 10 bit, 2 20 bit, 2 100 bit, 10 10 bit or other, etc.

[0219] In this embodiment, the hardware control and timing system 401 controls the second optical module 432 according to the aforementioned first information, so that the second optical module 432 arranges the first optical tweezers in the magneto-optical trap according to the first method to obtain an atomic array, such as... Figure 6 The first atomic array shown, or Figure 14 (d) shows the atomic array.

[0220] (III) Quantum state preparation and manipulation.

[0221] In the embodiments of this application, when the atomic system prepares the atomic array, the initial state of the auxiliary bits is all in the 0 state. To manipulate the quantum state of the data bits, the global light couples the 1-state and Rydberg state of the data / auxiliary bits, without affecting the 0-state. Figure 13 (7) in the diagram is the state preparation of the atomic array obtained in (II).

[0222] In an atomic array, atoms can be manipulated in parallel using global light or microwaves. Addressing manipulation light, focused onto a specific array position by an objective lens, can independently manipulate selected atoms. For example... Figure 13 (8) in the equation is to perform logic gate operations on the atomic array that has been prepared.

[0223] (iv) Quantum state readout.

[0224] like Figure 13 (9) represents the quantum computation results of obtaining the first and second information after fluorescence imaging of the atomic array after logic gate operations. For specific implementation methods of quantum state readout, please refer to the aforementioned... Figure 12 The description of that will not be repeated here.

[0225] In the above Figure 13 Of the contents shown in (1) to (9), (1) to (3) take about 500 milliseconds (ms), (4) takes about 10 ms, (5) takes about 10 ms, and (6) takes a significant increase depending on the size of the atomic array, such as (6) taking several hundred milliseconds or longer, (7) and (8) taking about 1 ms, and (9) taking about 10 ms.

[0226] Compared with the above Figure 13 The quantum computing method provided in this application optimizes the atomic arrangement process, such as... Figure 15 As shown, Figure 15 This is a flowchart illustrating a quantum computing method provided in this application. Figure 15 The provided quantum computing method includes the following four processes: (i) magneto-optical trap preparation and cooling; (ii) optical tweezers array loading and rearrangement; (iii) quantum state preparation and manipulation; and (iv) quantum state readout. The following sections, with reference to the accompanying figures, will describe these processes in detail. Figure 15 The four processes are illustrated by example.

[0227] (I) Fabrication and cooling of magneto-optical trap.

[0228] Please see Figure 15 , Figure 15 (1) in the text refers to the preparation of atomic groups (or atomic clouds). Figure 15(2) in the text refers to the fabrication of the optical tweezers array and the random loading of atoms. Regarding... Figure 15 The specific implementation of (a) in section (a) can be referred to the above. Figure 13 The description in (a) is omitted here. Optionally, the amount of data in the first information is related to the bit width of the qubit that the atomic array can represent. For example, the bit width of the qubit that the atomic array can represent is greater than or equal to the amount of data in the first information.

[0229] In the first optional scenario, the bit width of the qubits represented by the atomic array is greater than the data size of the first information. For example, if the bit width of the qubits represented by the atomic array is 10 bits, then the data size of the first information is 9 bits, 8 bits (1 byte), or other values.

[0230] In the second alternative scenario, the bit width of the qubits that the atomic array can represent is equal to the amount of data in the first information. For example, if the bit width of the qubits that the atomic array can represent is 10 bits, then the amount of data in the first information is 10 bits.

[0231] The two possible scenarios described above are merely examples of the bit width of the qubits that can be characterized by the atomic array provided in this embodiment, and should not be construed as limiting this application. In some optional scenarios, an atomic array can be used to characterize qubits with smaller or larger bit widths, such as 4-bit, 2-bit, etc. 10 bit, 2 20 bit, 2 100 bit, 10 10 bit or other, etc.

[0232] (ii) Loading and rearrangement of optical tweezer array.

[0233] Please see Figure 15 , Figure 15 (3) refers to the preparation of the state and the operation of the Rydberg gate. Figure 15 (4) in the diagram refers to filling a single-atom array with an internal state-dependent array light.

[0234] The following is combined Figures 16 to 19 ,right Figure 15 Examples of (3) and (4) are provided.

[0235] Figure 16 A schematic diagram of the structure of an atomic system provided in this application Figure 5 , mentioned above Figure 5 , Figure 8 as well as Figure 12 The content already described will not be repeated. Figure 16 The provided atomic system 400 also includes a state preparation optical module 440.

[0236] Before rearranging the first atomic array, the atomic arrangement method provided in this application includes step 0: the state preparation light module 440 sends state preparation light to the atomic cavity 420 to prepare all atoms in the first atomic array into a first state. For example, the first state is the |1> state.

[0237] The rearrangement process of the first atomic array includes Rydberg excitation and internal state-dependent shift processes. The following section combines... Figure 17 The principle of Rydberg excitation and internal state-dependent migration process is illustrated by an example. Figure 17 This is a schematic diagram illustrating the Rydberg excitation and internal state-dependent shift provided in this application. Please refer to [link / reference]. Figure 17 Atoms are selectively prepared onto specific internal states, and atoms in a specific internal state are moved by an internal state-dependent array of light without affecting atoms in other internal states.

[0238] In one alternative implementation, the intrinsic state-dependent array light is constrained as optical tweezers. Optical tweezers are micrometer-scale (or larger or smaller) light spots obtained by focusing parallel laser light through a microscope. These spots can be used to form three-dimensional optical potential wells, where atoms can be trapped at the lowest potential energy points.

[0239] In another alternative implementation, the internal state-dependent array light is constrained as an optical lattice. An optical lattice refers to a periodic mesh potential well formed by the interference of multiple laser beams, in which cold atoms are loaded and arranged in a spatial periodic pattern, similar to a "crystal structure" in solid-state physics.

[0240] The optical tweezers and optical lattices described above are merely physical forms of internal state dependent array light provided in the embodiments of this application. According to the development and changes in physics, internal state dependent array light can also be constrained to other physical forms, which is not limited in this application.

[0241] The positions of atoms in different internal states after being irradiated by the internal state-dependent array light are explained below, based on the constraint of the internal state-dependent array light as optical tweezers.

[0242] In one possible example, only atoms in the |0> state will sense the internal state-dependent array light and be moved to the target array. See, for example, [link to example]. Figure 17 An atom in the |0> state is trapped in the second optical tweezers / atomic ensemble optical tweezers at its initial position. When the atom is irradiated by the state-dependent optical tweezers formed by the internal state-dependent array light, it moves to the final position. An atom in the |0> state is trapped in the first optical tweezers / single-atom optical tweezers at its final position.

[0243] In another possible example, an atom in the |1> state, after being illuminated by an internal state-dependent array of light, remains in its original position. See also... Figure 17An atom in the |1> state will be trapped in the second optical tweezers / atomic ensemble optical tweezers at its initial position. When the atom is irradiated by the state-dependent optical tweezers formed by the internal state-dependent array light, its final position is no different from its initial position. That is, the position of the atom in the |1> state remains unchanged after being irradiated by the internal state-dependent array light.

[0244] The following exemplifies the Rydberg excitation process by taking steps ① to ④ as examples, and the internal state-dependent movement process by taking step ⑤ as an example, based on the constraint of the internal state-dependent array light as optical tweezers.

[0245] Step ①: The second optical module 432 emits first-atom Rydberg light into the atomic cavity 420, exciting the M atoms in the first layer of the first atomic array to the second state. That is, after the second optical module 432 performs a single-atom Rydberg operation on the first atomic array, the M atoms in the first layer are excited to the second state, such as the |r> state.

[0246] Step ②: The second optical module 432 emits Rydberg light from the first ensemble array into the atomic cavity 420, which excites NM atoms in the unpaired physical bit ensemble of the first atomic array to the second state (|r> state), while the atoms in the paired physical bit ensemble will not be excited to the second state (|r> state).

[0247] The principle behind step ② is as follows: There is a Rydberg interaction between the paired physical bit ensemble and the corresponding atom. Therefore, all atoms in the paired physical bit ensemble cannot be excited to a Rydberg state (|r> state) and will remain in the |1> state. There is no Rydberg interaction between the unpaired physical bit ensemble and the corresponding atom. Therefore, only one atom in the unpaired physical bit ensemble will be excited to a Rydberg state (|r> state).

[0248] Furthermore, to achieve the function of step ⑤ above, the wavelength of the internal state dependent array light is one of a set plurality of values, which are determined according to the atom types in the first atom array, such as including a first wavelength. For example, if the internal state dependent array light is the first wavelength, the internal state dependent array light will move atoms in the third state but will not move atoms in the first state.

[0249] The following, in conjunction with Table 1, provides an exemplary illustration of the wavelengths of internal state-dependent array light that can be used for several types of atoms.

[0250] Table 1

[0251]

[0252] The wavelengths of the internal state-dependent array light shown in Table 1 above are merely examples provided in the embodiments of this application and should not be construed as limiting this application. Based on the development and evolution of quantum computing technology, the atomic system and atomic arrangement method provided in this application can be applied to more types of atoms, and these atoms can also use beams of more wavelengths to achieve the aforementioned effects of the internal state-dependent array light; this application does not limit this.

[0253] Step ③: The second optical module 432 emits the second ensemble array Rydberg light into the atomic cavity 420, de-exciting NM atoms to the third state. This third state is, for example, the |0> state.

[0254] Step 4: The second optical module 432 emits second atomic Rydberg light into the atomic cavity 420, de-exciting M atoms to the first state (|1> state).

[0255] Step 5: The second optical module 432 emits internal state dependent array light into the atomic cavity 420, moving NM atoms in the third state (|0> state) of the first atomic array to the first layer to obtain the second atomic array.

[0256] In this embodiment, the second region covered by the internal state-dependent array light includes the first region. Atoms in the |0> state within the atomic array located in the first region can be controlled by the internal state-dependent array light, which does not move atoms in other states. This achieves atomic rearrangement of specific internal states within the atomic array, which helps reduce the time required for atomic rearrangement and improves the efficiency of quantum computing.

[0257] The following is combined Figure 18 and Figure 19 Regarding the above Figure 15 The provided (ii) optical tweezers array loading and rearrangement are illustrated by way of example.

[0258] Figure 18 The diagram below illustrates a rearrangement method for an atomic arrangement provided in this application. The rearrangement process of the atomic arrangement method includes the following (A) to (D).

[0259] (A) Loading and state preparation: The first optical tweezers of the first layer are used to randomly load single atoms, and the second optical tweezers of the second layer are used to load the atomic ensemble. At the same time, the loaded first atomic array is prepared to the |1> state using state preparation light.

[0260] (B) Rydberg excitation: This creates an atom in the |0> state in the second optical tweezers corresponding to the vacant first optical tweezers in the first layer. The principle of Rydberg excitation can be found in the description of step ② above, and will not be repeated here.

[0261] (C) Internal state dependent array light global parallel movement: Move atoms in the |0> state in the second layer to the first optical tweezers in the vacant first layer.

[0262] (D) Defect-free atomic array: The first atomic array is rearranged to obtain the second atomic array. All atoms in the first layer of the second atomic array are captured by the first optical tweezers. Therefore, the first layer of the second atomic array is also called a defect-free single-atom array.

[0263] For an atomic array of the same composition, for the first optical tweezers in the first layer that has not captured any atoms, only the atoms to be filled (such as atoms in the |0> state) are affected by the internal state-dependent array light. This internal state-dependent array light can simultaneously move in parallel on all atoms in the |0> state within the entire target area (first region) along a fixed path. The atomic system does not need to perform path calculations for the atoms, reducing the time required for atomic arrangement. Even as the size of the atomic array increases, the time required for atomic arrangement remains a fixed single parallel movement time; the time required for atomic arrangement does not increase with the size of the atomic array.

[0264] Based on the above Figure 16 The provided atomic system 400, and Figure 17 and Figure 18 The provided content addresses the impact of steps 0 and ① through ⑤ on defect-free and defective single-atom arrays. The following section will combine these findings with... Figure 19 Provided as an example, Figure 19 This is a comparison diagram of different single-atom arrays provided in this application.

[0265] Please see Figure 19 In the first atomic array, where the first layer is a defect-free single-atom array, after step 0, all atoms are in the |1> state after being irradiated with state preparation light. After step ①, the single atoms are in the |r> state after being irradiated with atomic Rydberg light (such as the first atomic Rydberg light mentioned above), and the atomic ensemble is in the |1> state. After steps ② and ③, the single atoms are in the |1> state, and the atomic ensemble is in the |1> state. After step ④, the single atoms are in the |1> state after being irradiated with atomic Rydberg light (such as the second atomic Rydberg light mentioned above), and the atomic ensemble is in the |1> state. After step ⑤, the internal states and positions of the single atoms and the atomic ensemble remain unchanged.

[0266] Please see Figure 19In the first atomic array, where the first layer is a defective single-atom array, after steps 0 and ①, all atoms are in the |1> state after being irradiated by state preparation light. After steps ② and ③, the single atom remains vacant, and only one atom in the atomic ensemble is placed in the |0> state, while the other atoms in the atomic ensemble are in the |1> state. After step ④, the single atom remains vacant, and only one atom in the atomic ensemble is in the |0> state, while the other atoms in the atomic ensemble are in the |1> state. After step ⑤, the internal state-dependent array light moves the atom in the |0> state in the atomic ensemble to the vacant position of the single atom, while the internal states and positions of the other atoms in the atomic ensemble remain unchanged. That is, using internal state-dependent array light to move atoms only moves the single atom in the |0> state to the vacant single-atom optical tweezers, while the other atoms in the ensemble, being in the |1> state, are unaffected by the internal state-dependent array light and remain in the second optical tweezers corresponding to the atomic ensemble.

[0267] Combination Figures 16 to 19 As can be seen from the content, by controlling the first optical tweezers corresponding to the atoms representing data bits and the second optical tweezers corresponding to the atomic ensembles representing auxiliary bits, a coordination state preparation operation is performed to enable the atoms of the data bits and their paired atomic ensembles to undergo Rydberg operations. Through the Rydberg blocking effect, the loading information of the single-atom optical tweezers is transferred to the internal state information of the atomic ensemble. When a single-atom optical tweezer (the first optical tweezer) is vacant, a single atom in the atomic ensemble will be excited to another specific internal state. Through optical tweezers or optical lattices formed by internal state-dependent array light, a single atom can be parallelly added from the atomic ensemble to all vacant single-atom optical tweezer arrays.

[0268] (III) Quantum state preparation and manipulation.

[0269] about Figure 15 The specific implementation of (iii) can be referred to the foregoing. Figure 13 The description of (iii) in the text will not be repeated here.

[0270] (iv) Quantum state readout.

[0271] like Figure 15 (7) represents the quantum computation results of obtaining the first and second information after fluorescence imaging of the atomic array after logic gate operations. For specific implementation methods of quantum state readout, please refer to the preceding text. Figure 12 class Figure 13 The description of that will not be repeated here.

[0272] Throughout the entire rearrangement feedback process of the atomic array, only logic gate operations acting on the atoms are involved (implemented through the Rydberg excitation process described above), without involving information processing and feedback outside the atomic system (such as...). Figure 13(4) Fluorescence imaging is performed in the middle. Therefore, through appropriate logic gate circuit design, the coherence of the atomic system can be preserved to a certain extent, and quantum error correction can be performed. In addition, in the technical solution provided by the embodiments of this application, the same atomic array includes a single-atom array of the first layer and an atomic ensemble of the second layer, which gives full play to the role of the atomic ensemble as an atomic library and enhances information reading. This structure itself also has the potential for further development.

[0273] In the above Figure 15 Of the contents shown in (1) to (7), (1) to (2) take about 500 milliseconds (ms), (3) takes about 10 μs, (4) takes about 100 μs, (5) and (6) take about 1 ms, and (7) takes about 10 ms. Figure 15 The time consumption differences of the quantum computing methods shown are as follows Figure 13 The time-consuming part of the quantum computing method shown is: Figure 15 In (ii), the loading and rearrangement time of the optical tweezers array is significantly reduced, and the second-layer atomic ensemble can serve as the atomic library for the first-layer single-atom array. In scenarios involving batch execution of quantum computing, this can greatly reduce the need for repetitive execution. Figure 15 The number of times (1) to (2) is reduced, which means the need for loading and rearranging the optical tweezers array is reduced. After the time consumption of atomic arrangement is reduced, the time required for quantum computing is reduced, and the efficiency of quantum computing is improved.

[0274] In summary, this application's embodiments convert the loading status of optical tweezers into atomic internal state information, and in conjunction with internal state-dependent optical tweezers, achieve a rapid parallel atomic rearrangement and filling scheme and its implementation system that does not require fluorescence detection. This significantly reduces the rearrangement time by more than two orders of magnitude, and the time does not increase with the size of the atomic array. In the scheme design of this application's embodiments, atomic movement is achieved through an internal state-dependent array light. The wavelength of this internal state-dependent array light is related to the type of atoms used in the atomic system. Simultaneously, the internal state-dependent array light needs to be focused to form an optical tweezers array or optical lattice covering the entire target area. This characteristic is unique to this scheme, so the wavelength of the internal state-dependent array light can be measured and detected by a wavelength meter. In a preferred embodiment, the intensity distribution of the internal state-dependent array light can also be set, and this intensity distribution information can be acquired by a camera.

[0275] The method steps in the embodiments of this application can also be implemented by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a network device or a terminal device. Alternatively, the processor and storage medium can exist as discrete components in electronic devices and multimedia devices.

[0276] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video disc (DVD); or it can be a semiconductor medium, such as a solid-state drive (SSD).

[0277] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An atomic system, characterized in that, include: An atomic source is used to provide multiple atoms; An atomic cavity, connected to the atomic source, is used to store atoms provided by the atomic source; A first optical module is configured to: generate multiple optical tweezers in the atomic cavity, and arrange the multiple optical tweezers according to first information to obtain a first atomic array; wherein, the first atomic array includes: a first layer and a second layer in a first region, the first layer includes N first optical tweezers, the second layer includes N second optical tweezers, the first optical tweezers and the second optical tweezers are paired one-to-one, each first optical tweezer is used to capture one atom, each second optical tweezer is used to capture a set of atomic ensembles, and the first layer includes M atoms, the second layer includes N sets of atomic ensembles, N≥M; The second optical module is used to: emit internal state-dependent array light into the atomic cavity to rearrange the first atomic array to obtain the second atomic array; In the second atomic array, the first layer includes N atoms, the N atoms include the M atoms and the NM atoms of the internal state dependent array light moving from the NM group of atoms in the first layer, and one atom of the N atoms is used to characterize a physical bit; In the second atomic array, the second layer includes N sets of atomic ensembles, and one set of atomic ensembles in the N sets of atomic ensembles is used to characterize the auxiliary bit paired with the physical bit; the physical bit represented by the N atoms matches the first information, and the number of atoms in the first atomic array is the same as the number of atoms in the second atomic array.

2. The atomic system according to claim 1, characterized in that, Also includes: The third optical module is used to: generate global light based on the second information, the global light being used to illuminate the second atomic array; A quantum bit measurement unit is used to: collect scattered photons generated in the second atomic array after being irradiated by a probe beam, and determine the quantum computing result between the first information and the second information based on the scattered photons.

3. The atomic system according to claim 1 or 2, characterized in that, Also includes: A state preparation optical module is used to send state preparation light to the atomic cavity to prepare all atoms in the first atomic array into the first state; The second optical module is specifically used for: The first atomic Rydberg light is emitted into the atomic cavity to excite the M atoms contained in the first layer of the first atomic array to the second state; The first ensemble array Rydberg light is emitted into the atomic cavity to excite NM atoms in the unpaired physical bit ensemble contained in the first atomic array to the second state; A second ensemble array Rydberg beam is emitted into the atomic cavity to de-excite the NM atoms to the third state; A second atomic Rydberg beam is emitted into the atomic cavity to de-excite the M atoms to the first state; An internal state-dependent array light is emitted into the atomic cavity to move NM atoms in the third state of the first atomic array to the first layer, thereby obtaining the second atomic array.

4. The atomic system according to claim 3, characterized in that, In the second atomic array, for the first atom among the NM atoms contained in the first layer, the first atom is moved from the first atomic ensemble in the second layer to the first layer after being irradiated by the internal state dependent array light. The first optical tweezers that capture the first atom are paired with the second optical tweezers that capture the first atomic ensemble.

5. The atomic system according to claim 3 or 4, characterized in that, The wavelength of the internal state-dependent array light is one of a plurality of preset values, which are determined according to the atom types in the first atom array, and the plurality of values ​​include a first wavelength; If the internal state dependent array light is the first wavelength, the internal state dependent array light will move the atoms in the third state but will not move the atoms in the first state.

6. The atomic system according to any one of claims 1-5, characterized in that, The second region covered by the internal state-dependent array light includes the first region.

7. The atomic system according to any one of claims 1-6, characterized in that, The internal state-dependent array light is constrained as optical tweezers or an optical lattice.

8. The atomic system according to any one of claims 1-7, characterized in that, The first layer and the second layer are located in different planes, and there is a first bias value between an atom in the first layer and an ensemble of atoms in the second layer that are paired with the atom in the first layer along a first direction, the first direction being a direction perpendicular to the first layer and the second layer; Alternatively, the first layer and the second layer are located in the same plane, and there is a second bias value between an atom in the first layer and an ensemble of atoms in the second layer that are paired with the atom.

9. The atomic system according to any one of claims 1-8, characterized in that, The first information is either input information for the quantum computing process or adjustment information for the quantum error correction process.

10. A method for arranging atoms, characterized in that, Applied to an atomic system, the atomic system includes: an atomic source, an atomic cavity, a first optical module and a second optical module, wherein the atomic cavity is connected to the atomic source; The atomic arrangement method includes: The atomic source provides multiple atoms to the atomic cavity; The first optical module generates multiple optical tweezers in the atomic cavity and arranges the multiple optical tweezers according to the first information to obtain a first atomic array; wherein, the first atomic array includes: a first layer and a second layer in a first region, the first layer includes N first optical tweezers and the second layer includes N second optical tweezers, the first optical tweezers and the second optical tweezers are paired one by one, each first optical tweezer is used to capture one atom and each second optical tweezer is used to capture a set of atomic ensembles, and the first layer includes M atoms and the second layer includes N sets of atomic ensembles, N≥M; The second optical module emits internal state-dependent array light into the atomic cavity, causing the first atomic array to be rearranged to obtain the second atomic array; In the second atomic array, the first layer includes N atoms, the N atoms include the M atoms and the NM atoms of the internal state dependent array light moving from the NM group of atoms in the first layer, and one atom of the N atoms is used to characterize a physical bit; In the second atomic array, the second layer includes N sets of atomic ensembles, and one set of atomic ensembles in the N sets of atomic ensembles is used to characterize the auxiliary bit paired with the physical bit; the physical bit represented by the N atoms matches the first information, and the number of atoms in the first atomic array is the same as the number of atoms in the second atomic array.

11. The atomic arrangement method according to claim 10, characterized in that, The atomic system also includes a third optical module and a quantum bit measurement unit; The atomic arrangement method further includes: The third optical module generates global light based on the second information, and the global light is used to illuminate the second atomic array. The quantum bit measurement unit collects the scattered photons generated in the second atom array after being irradiated by the probe beam, and determines the quantum computing result between the first information and the second information based on the scattered photons.

12. The atomic arrangement method according to claim 10 or 11, characterized in that, The atomic system also includes a state-preparation optical module; Before the first atom array is rearranged, the method further includes: The state preparation optical module sends state preparation light to the atomic cavity to prepare all atoms in the first atomic array into the first state; The second optical module emits first atomic Rydberg light into the atomic cavity, exciting M atoms in the first layer of the first atomic array to the second state; The second optical module emits Rydberg light from the first ensemble array into the atomic cavity, exciting NM atoms in the unpaired atomic ensemble contained in the first atomic array to the second state; The second optical module emits a second ensemble array Rydberg beam into the atomic cavity, de-exciting the NM atoms to the third state; The second optical module emits second atomic Rydberg light into the atomic cavity, de-exciting the M atoms to the first state; Furthermore, the second optical module emits internal state-dependent array light into the atomic cavity, moving NM atoms in the third state of the first atomic array to the first layer to obtain the second atomic array.

13. The atomic arrangement method according to any one of claims 10-12, characterized in that, The second region covered by the internal state-dependent array light includes the first region.

14. The atomic arrangement method according to any one of claims 10-13, characterized in that, The internal state-dependent array light is constrained as optical tweezers or an optical lattice.

Images