Quantum computing system and method

Abstract

The present invention relates to the technical field of quantum computing. Disclosed are a quantum computing system and method. Using a multi-component atomic system and cooperating with a specific atomic spacing relationship in an atomic array is beneficial to eliminating a next-nearest-neighbor interaction force in the atomic array, and only retaining the nearest-neighbor interaction force. Furthermore, global Rydberg light (simply referred to as global light) is used to irradiate the atomic array, so that information corresponding to a data bit corresponding to a target first atom is transmitted to a group of auxiliary bits represented by second atoms, thereby implementing a low crosstalk data transmission process in the atomic array, greatly reducing the sensitivity to the positions of atoms and the thermal motion of atoms, improving the fidelity and parallelism of information transmission, and thereby reducing the delay of quantum computing.

Description

A quantum computing system and method

[0001] This application claims priority to the Chinese Patent Application No. 202410775473.2, filed on June 14, 2024, entitled “A quantum computing system and method”, and to the Chinese Patent Application No. 202510173612.9, filed on February 14, 2025, entitled “A quantum computing system and method”, both of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of quantum computing, and in particular to a quantum computing system and method. BACKGROUND

[0003] With the continuous development of technology, traditional computer computing cannot meet the computing resource demand of large operation tasks, such as quantum chemistry simulation, optimal path finding, and large number factor decomposition, and a quantum computing system based on neutral atom architecture (neutral atom system) emerges as the times require. The neutral atom system forms an optical tweezer (light tweezer) by focusing a trapped light with an objective lens, and uses the light tweezer to capture atoms cooled by laser. The captured atoms are regularly arranged in a vacuum glass cavity to form an atomic array to represent a quantum bit. Generally, irradiating the atoms in the atomic array with global and addressing light can achieve parallel or independent operation of the quantum bit, such as changing the state of the quantum bit (0 state, 1 state, or superposition state of 0 and 1). In the process of reading the quantum bit, after irradiating the atoms in the atomic array with probe light, scattered photons are obtained, an electronic signal is determined according to the photons collected from the objective lens, and the state of the quantum bit is determined according to the electronic signal, i.e., the result of quantum computing is obtained.

[0004] In the process of operating a logic gate of two quantum bits (two-bit logic gate), the neutral atom needs to be excited from the ground state to the Rydberg state; the electron cloud between different atoms in the Rydberg state increases by multiple orders of magnitude, so that the atoms in different light tweezers generate sufficient interatomic forces, thereby realizing multi-qubit operation. Among them, the interatomic force depends on the size of the electron cloud and the atomic spacing, the size of the electron cloud is determined by the principal quantum number (n) of the Rydberg state, and the interatomic force is proportional to n 11 and inversely proportional to the atomic spacing (R 6 ).

[0005] In a quantum computing system, the distance between adjacent atoms of the same group is small, and when the adjacent atoms are irradiated by the same Rydberg excitation light, at most one of the adjacent atoms can be excited to the Rydberg state, i.e., the Rydberg blockade effect. Therefore, in order to operate a two-bit logic gate in the quantum computing system, it is necessary to adjust the distance between the adjacent atoms. Since the speed of atomic movement is limited by the depth of the optical tweezers, it takes hundreds of microseconds to move each time, which is much longer than the general gate operation time, thereby limiting the system coherence and the computing depth. In addition, by controlling the atomic interaction through the atomic distance, the atomic array needs a large change in the distance between the atoms, which reduces the spatial density of the atomic array. Under the limitation of the visual range of the objective lens, the number of controllable atoms is affected. SUMMARY

[0006] The present application provides a quantum computing system and method, which solves the problem of the need to adjust the distance between adjacent atoms in order to control the atomic interaction force, reduces the sensitivity to the position of the atom and the thermal motion of the atom, improves the information transmission fidelity and parallelism, thereby increasing the computing bit width of the quantum computing system and reducing the delay of quantum computing.

[0007] The present application adopts the following technical solutions.

[0008] In a first aspect, the present application provides a quantum computing system. The quantum computing system comprises an atom source, an atom cavity, an optical tweezer unit, a global light emitter, and a qubit measurement unit. The atom source is configured to provide a plurality of types of atoms. The atom cavity is connected to the atom source and is configured to store the atoms provided by the atom source, wherein the atoms provided by the atom source include a plurality of first atoms representing data bits and one or more second atoms representing auxiliary bits, the auxiliary bits being configured to temporarily store information corresponding to the data bits. The optical tweezer unit is configured to generate a plurality of optical tweezers in the atom cavity and arrange the optical tweezers that have captured the atoms in the atom cavity according to first information to obtain an atomic array. The atomic array includes a group of second atoms representing the auxiliary bits and target first atoms corresponding to the data bits paired with the auxiliary bits, the group of second atoms includes one or more target second atoms, the target first atoms and the group of second atoms are located in different layers, and an axis formed by the target first atoms and the group of second atoms is perpendicular to the layer containing the group of second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between another group of target second atoms adjacent to the group of second atoms and the target second atoms, and the second distance is a distance between the group of second atoms and the target first atoms. The global light emitter is configured to generate global light according to second information, the global light being configured to irradiate the atomic array to transfer the information corresponding to the data bits corresponding to the target first atoms to the auxiliary bits represented by the group of second atoms. The qubit measurement unit is configured to collect scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by a probe beam, and determine a quantum computing result of the first information and the second information according to the scattered photons.

[0009] In the first aspect of the present application, a multi-component atomic system is used in combination with a specific interatomic spacing relationship in the atomic array to eliminate the next nearest neighbor interaction force in the atomic array and only retain the nearest neighbor interaction force. Furthermore, global Rydberg light (referred to as global light) is used to irradiate the atomic array to transfer the information corresponding to the data bits corresponding to the target first atoms to the auxiliary bits represented by the group of second atoms, thereby realizing a low crosstalk data transfer process in the atomic array, greatly reducing the sensitivity to the position of the atom and the thermal motion of the atom, improving the information transmission fidelity and parallelism, and thereby reducing the delay of quantum computing.

[0010] In combination with the quantum computing system provided in the first aspect, in an optional implementation manner, the reference value is K, K=tanθ, θ is greater than or equal to 49.7° and less than or equal to 59.7°. For example, the minimum value of θ is 49.7°, the maximum value of θ is 59.7°, or the value of θ is 54.7°.

[0011] In an optional implementation of the quantum computing system provided in the first aspect, in the atomic array, an interatomic interaction force between the target first atom and the one group of second atoms is greater than an interatomic interaction force between the target first atom and other groups of second atoms, and the other groups of second atoms are second atoms in the atomic array other than the one group of second atoms.

[0012] In an optional implementation of the quantum computing system provided in the first aspect, the optical tweezer unit is further configured to: move, according to the third information, an optical tweezer in which the one group of second atoms is captured, to obtain a target atomic array. The target atomic array includes: the one group of second atoms representing the ancillary bit, and a target first atom of the data bit paired with the ancillary bit, one or more target second atoms in the one group of second atoms and the target first atom are located in different layers, and an axis formed by the target first atom and one target second atom is perpendicular to a layer containing the one group of second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the one target second atom and a neighboring target second atom in the one group of second atoms, and the second distance is a distance between the one group of second atoms and the target first atom. The quantum bit measurement unit is further configured to: collect scattered photons generated by the one group of second atoms corresponding to the ancillary bit after being irradiated by the probe light beam, and determine the quantum computing result of the third information and the second information according to the scattered photons.

[0013] In an optional implementation of the quantum computing system provided in the first aspect, the global light emitter includes: an excitation light source and an optical path modulation component connected to the excitation light source. The excitation light source is configured to provide an irradiation light beam, and the optical path modulation component is configured to: process a light parameter of the irradiation light beam according to the second information to obtain the global light. The light parameter includes one or a combination of several of the following: light beam direction, polarization, and frequency.

[0014] In a first possible example, the optical path modulation component includes: an acousto-optic modulator (AOM) and a beam splitter.

[0015] In a second possible example, the optical path modulation component includes: an electro-optic modulator (EOM) and a polarizing beam splitter (PBS).

[0016] In a third possible example, the optical path modulation component includes: a digital micromirror device (DMD).

[0017] With reference to the quantum computing system of the first aspect, in an optional implementation, the plurality of optical tweezers have different wavelengths, wherein optical tweezers of a first wavelength range are used to trap the first atoms, and optical tweezers of a second wavelength range are used to trap the second atoms.

[0018] In a second aspect, the present application provides a quantum computing method. The quantum computing method is applied to the quantum computing system of the first aspect or any of the optional implementation modes of the first aspect. The quantum computing method provided by the present application includes: an atom source provides a plurality of types of atoms, and an atom cavity stores the atoms provided by the atom source. The atoms provided by the atom source include: a plurality of first atoms representing data bits, and a plurality of second atoms representing auxiliary bits. The auxiliary bits are used to temporarily store information corresponding to the data bits. An optical tweezer unit generates a plurality of optical tweezers in the atom cavity, and arranges the optical tweezers that have trapped the atoms in the atom cavity according to first information to obtain an atom array. The atom array includes: a group of second atoms representing the auxiliary bits, and target first atoms corresponding to the data bits paired with the auxiliary bits. The group of second atoms includes one or more target second atoms. The target first atoms and the group of target second atoms are located in different layers, and an axis formed by the target first atoms and the group of target second atoms is perpendicular to the layer containing the group of second atoms. A ratio between a first distance and a second distance is a reference value. The first distance is a transverse distance or a longitudinal distance between the group of target second atoms and another group of target second atoms adjacent to the group of target second atoms. The second distance is a distance between the group of target second atoms and the target first atoms. A global light emitter generates global light according to second information. The global light is used to irradiate the atom array, so that the information corresponding to the data bits corresponding to the target first atoms is transmitted to the auxiliary bits represented by the group of second atoms. A quantum bit measurement unit collects scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by a probe beam, and determines a quantum computing result of the first information and the second information according to the scattered photons.

[0019] In the second aspect of the present application, the global light is used to irradiate the atom array, so that the information corresponding to the data bits corresponding to the target first atoms is transmitted to the auxiliary bits represented by the group of second atoms. Therefore, a low cross-talk data transmission process in the atom array is realized, the sensitivity to the positions of the atoms and the thermal motion of the atoms is greatly reduced, the information transmission fidelity and parallelism are improved, and the delay of quantum computing is reduced.

[0020] With reference to the quantum computing method of the second aspect, in an optional implementation, the reference value is K, K=tanθ, θ is greater than or equal to 49.7°, and θ is less than or equal to 59.7°. For example, the minimum value of θ is 49.7°, the maximum value of θ is 59.7°, or the value of θ is 54.7°.

[0021] In an optional implementation of the quantum computing method provided in the second aspect, the optical tweezer unit moves an optical tweezer in which a second group of atoms is captured according to the third information to obtain a target atomic array. The target atomic array includes the second group of atoms representing the ancillary qubit and a first target atom of the data qubit paired with the ancillary qubit. One or more target atoms in the second group of atoms are located in different layers from the first target atom, and an axis formed by the first target atom and the second group of atoms is perpendicular to the layer in which the second group of atoms is located, and a ratio between a first distance and a second distance is a reference value. The first distance is a transverse distance or a longitudinal distance between the second group of atoms and another group of atoms adjacent to the second group of atoms, and the second distance is a distance between the second group of atoms and the first target atom. The quantum bit measurement unit collects scattered photons generated by the second group of atoms corresponding to the ancillary qubit after being irradiated by the probe beam, and determines the quantum computing result of the third information and the second information according to the scattered photons.

[0022] In an optional implementation of the quantum computing method provided in the second aspect, in the atomic array, an atomic interaction between the target first atom and the second group of atoms is greater than an atomic interaction between the target first atom and other groups of atoms, and the other groups of atoms are second atoms other than the second group of atoms in the atomic array.

[0023] In an optional implementation of the quantum computing method provided in the second aspect, the global light emitter includes an excitation light source and an optical path modulation component connected to the excitation light source. The excitation light source is configured to provide an irradiation beam, and the optical path modulation component is configured to process a light parameter of the irradiation beam according to the second information to obtain the global light. The light parameter includes one or a combination of the following: a beam direction, a polarization, and a frequency.

[0024] In a first possible example, the optical path modulation component includes an AOM and a beam splitter.

[0025] In a second possible example, the optical path modulation component includes an EOM and a PBS.

[0026] In a third possible example, the optical path modulation component includes a DMD.

[0027] In an optional implementation of the quantum computing method provided in the second aspect, the wavelengths of the plurality of optical tweezers are different, and optical tweezers in a first wavelength range are used to capture first atoms, and optical tweezers in a second wavelength range are used to capture second atoms.

[0028] In an optional implementation of the quantum computing system provided in the first aspect and the quantum computing method provided in the second aspect, the first atom is a Rubidium (Rb) atom, and the second atom is a Ytterbium (Yb) atom; or the first atom is a Ytterbium (Yb) atom, and the second atom is a Rubidium (Rb) atom.

[0029] On the basis of the implementation manners of the aspects provided in the application, further combinations can be made to provide more implementation manners, which are not described herein. BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a schematic diagram of different types of quantum numbers of atoms provided in the application;

[0031] FIG. 2 is a schematic diagram of magnetic quantum numbers provided in the application;

[0032] FIG. 3 is a schematic diagram of energy difference and dipole moment of a Rubidium atom provided in the application;

[0033] FIG. 4 is a schematic diagram of a CZ gate provided in the application;

[0034] FIG. 5 is a structural schematic diagram of a quantum computing system provided in the application;

[0035] FIG. 6A is a schematic diagram of loading of an atomic array provided in the application;

[0036] FIG. 6B is a schematic diagram of a first distance and a second distance provided in the application;

[0037] FIG. 7 is a schematic diagram of transitions of different Rydberg states of atoms provided in the application;

[0038] FIG. 8 is a schematic diagram of three types of interaction forces between atoms provided in the application;

[0039] FIG. 9A is a schematic diagram of an information control process and a quantum computing process provided in the application;

[0040] FIG. 9B is a schematic diagram of loading of an optical tweezer and an atomic array provided in the application;

[0041] FIG. 10 is a structural schematic diagram of a quantum computing system provided in the application;

[0042] FIG. 11 is a structural schematic diagram of three types of optical path modulation components provided in the application;

[0043] FIG. 12 is a schematic diagram of fast changing of optical parameters provided in the application;

[0044] FIG. 13 is a structural schematic diagram of a quantum computing system provided in the application;

[0045] FIG. 14 is a schematic diagram of an optical path of a quantum computing system provided by the present application;

[0046] FIG. 15 is a flowchart of a fast detection using auxiliary bits provided by the present application;

[0047] FIG. 16 is a flowchart of a non-local gate operation using single-atom auxiliary bits provided by the present application;

[0048] FIG. 17 is a schematic diagram of loading of an atomic array including multiple layers of auxiliary bits provided by the present application. DETAILED DESCRIPTION

[0049] The present application provides a quantum computing system and method, wherein the first information is used to determine the arrangement of the first atoms corresponding to the data bits and the second atoms corresponding to the auxiliary bits in the atomic array, and the second information is used to determine the global Rydberg light (global light) irradiating all the atoms in the atomic array. For the auxiliary bits temporarily storing the information corresponding to the data bits, the quantum computing system uses the global Rydberg light (global light) to irradiate a first group of first atoms corresponding to the data bits and a target second atom corresponding to the auxiliary bits, so that the information corresponding to the data bits corresponding to the target first atom is transferred to the auxiliary bits represented by a group of second atoms, thereby realizing a low cross-talk data transfer process in the atomic array, greatly reducing the sensitivity to the position of the atom and the thermal motion of the atom, improving the information transfer fidelity and parallelism, and thereby reducing the delay of quantum computing.

[0050] The present application can not only be applied to current quantum computing technology or quantum computing standards, but also to future quantum computing technology or quantum computing standards. The terms used in the implementation part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. First, some concepts that may be involved in the present application are briefly introduced.

[0051] 1. Quantum bit: the basic unit of quantum information. Unlike the classical bits in traditional binary computers, which can only be 0 or 1, quantum bits can not only be in 0 or 1 state, but also in superposition state of 0 and 1. Quantum bits have many different carriers, including superconducting circuits, ions, atoms, photons, quantum dots, etc.

[0052] 2. Logic gate: the basic logic operation unit in a quantum circuit.

[0053] 3. Energy level: a series of relatively stable states in a quantum system. These states correspond to a series of discrete energies.

[0054] 4. Quantum state: the state of a quantum system represented by a group of quantum numbers.

[0055] 5. Quantum number: a number used to describe a conserved physical quantity in a quantum system, by which the quantum state of the system is expressed.

[0056] 6. Principal quantum number (n): one of the quantum numbers that describe the atomic orbital, which indicates the electron shell, the distance from the nucleus, and the corresponding energy level.

[0057] 7. Orbital quantum number (1): one of the quantum numbers that describe the atomic orbital, which indicates the angular momentum of the electron orbit, and the shape of the corresponding electron cloud.

[0058] 8. Magnetic quantum number (m): one of the quantum numbers that describe the atomic orbital, which indicates the projection of the angular momentum of the electron in space, and the corresponding equivalent magnetic moment.

[0059] 9. Ground state: the lowest energy quantum state of an atom in a quantum computing system.

[0060] 10. Rydberg state: refers to the high excited state of an atomic or molecular system. Compared with the ground state atom, the electron cloud of the atom in the Rydberg state increases by several orders of magnitude.

[0061] 11. Optical tweezer array: after the laser beam is highly focused by the objective lens, it can be used to trap atoms, and multiple optical tweezers can be arranged in an array to form an optical tweezer array. The optical tweezer refers to the optical tweezer formed by focusing the trapping light through the objective lens.

[0062] 12. Component: refers to an isotope or element in this context.

[0063] 13. Magnetic optical trap: through a spatially varying magnetic field and laser cooling, atoms are cooled and collected to the center of the magnetic field, and the atom temperature can be cooled to hundreds to several uK. The magnetic optical trap is the first step of most atomic experiments.

[0064] 14. Hamiltonian: the total energy of a system, including the kinetic energy and potential energy of particles.

[0065] 15. Alkali metal: alkali metal refers to the six metal elements in the same group 1 in the periodic table: lithium, sodium, potassium, rubidium, cesium, and eka-cesium. Alkali metals all have one outermost electron belonging to the s orbital.

[0066] 16. Alkaline earth metal: alkaline earth metal refers to the six metal elements in the same group 2 in the periodic table: beryllium, magnesium, calcium, strontium, barium, and radium. Alkaline earth metals all have two outermost electrons belonging to the s orbital.

[0067] 17. Single-photon excitation: an atom absorbs a photon of excitation light from a lower energy quantum state, thereby being excited to a higher energy quantum state. The frequency and polarization of the photon of excitation light determine the quantum state to which it is excited.

[0068] 18. Two-photon excitation: An atom absorbs two photons of excitation light from a lower energy quantum state to a higher energy quantum state. The frequency and polarization of the two photons of excitation light together determine the quantum state to which the atom is excited.

[0069] 19. Dipole interaction: The interaction between two electric dipoles.

[0070] 20. C6: A commonly used parameter for the strength of interatomic interaction. The commonly used C6 for Rydberg states is about 100 GHz / (μm)2. 6 order of magnitude.

[0071] 21. Polarization: The phenomenon that the spatial distribution of the electric vector of light wave loses symmetry with respect to the direction of light propagation is called polarization of light. It is a phenomenon that the oscillation vector of the transverse wave of light (perpendicular to the direction of wave propagation) is biased to certain direction.

[0072] 22. Optical frequency: The abbreviation of optical frequency. The product of optical frequency and wavelength is the speed of light (c=299792458 m / s). In this article, optical frequency is also called frequency, which will not be repeated hereinafter.

[0073] 23. CZ gate: A kind of two-qubit gate. The two qubits are control qubit and target qubit respectively. The effect of this gate operation is that the system adds a phase of π when both qubits are in |1> state; otherwise, the system adds a phase of 0. In the basis of |00>, |01>, |10>, |11>, the corresponding transfer matrix is a 4x4 diagonal matrix with diagonal elements {1, 1, 1, -1}.

[0074] 24. Rydberg interaction: The interaction between two atoms in Rydberg state.

[0075] 25. Addressing light: A characteristic used to describe the spatial distribution of laser light. Addressing light only illuminates certain atoms on the atomic array. Physically, the addressing light can be a highly focused beam (e.g. spot diameter about one micron), which can be used to illuminate a single atom.

[0076] 26. Global light: A characteristic used to describe the spatial distribution of laser light. Global light illuminates all atoms on the atomic array at the same time. Physically, the global light can be a large spot light, which is used to illuminate the entire atomic array for global manipulation.

[0077] 27. Resonance: The frequency of laser light is equal to the frequency corresponding to the energy difference between two energy levels. This condition is called resonance.

[0078] 28. Detuning: The difference between the frequency of laser light and the frequency corresponding to the energy difference between two energy levels when they are not in resonance. It is denoted by the Greek letter Δ.

[0079] 29. Rabi frequency: a frequency parameter, denoted by the Greek letter Ω, equal to the angular frequency at which an atomic state oscillates between two relevant energy levels under the action of a laser.

[0080] 30. Block radius: a length parameter, dependent on the Rydberg state of the atoms in the experiment and the Rabi frequency at which the atoms are excited from the ground state to the Rydberg state. The strength of the Rydberg interaction between atoms decays with distance. When the interatomic distance is one block radius, the interaction strength is exactly equal to the Rabi frequency.

[0081] 31. Rydberg blockade: a physical phenomenon in which, when there are several atoms within a circle of radius equal to the block radius, only one atom can be excited to the Rydberg state, while the excitation of the other atoms is suppressed.

[0082] 32. π pulse: a laser pulse with a duration of π / Ω.

[0083] 33. 2π pulse: a laser pulse with a duration of 2π / Ω.

[0084] 34. Ensemble bit: in this document, refers to a plurality of atoms that are simultaneously trapped in the same optical tweezer. When the beam waist of the optical tweezer is expanded to several microns, the optical loss is greatly reduced, so the same optical tweezer can load multiple atoms.

[0085] The quantum state and the excitation process of the quantum state, the ground state and the Rydberg state of the atom, the two-bit gate, and the quantum computing system and method provided by the embodiments of the present application will be described in the following with reference to the accompanying drawings.

[0086] I. Quantum state and excitation process of quantum state

[0087] Taking the most common alkali metal atom in a neutral atomic system as an example, the atom can be regarded as being composed of a positively charged nucleus and a negatively charged electron. The principal quantum number n reflects the size of the electron cloud, and when the principal quantum number becomes larger, the electron cloud becomes more diffuse. The orbital quantum number reflects the shape of the electron cloud, and when the orbital quantum number increases, the number of nodes also increases, and the spatial distribution of the electron cloud also becomes more complex. The quantum state with an orbital quantum number of zero is called an s state, the quantum state with an orbital quantum number of one is called a p state, and the quantum state with an orbital quantum number of two is called a d state. The magnetic quantum number m reflects the projection of the angular momentum of the atom on the quantization axis, and when the magnetic quantum number changes, the equivalent magnetic moment of the atom also changes.

[0088] The excitation of the quantum state of an atom is generally carried out by irradiating the atom with laser light, and the change in the principal quantum number determines the frequency of the excitation light. As shown in FIG. 1, FIG. 1 is a schematic diagram of different types of quantum numbers of an atom provided by the present application. The change in the principal quantum number |n1-n2| is not limited (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 |n1-n2|, the higher the frequency of the excitation light required to adjust the principal quantum number.

[0089] Taking the transition of an atom between two adjacent quantum states as an example, as shown in FIG. 2, FIG. 2 is a schematic diagram of magnetic quantum numbers provided by the present application. The atom includes: a plurality of quantum states, and the excitation light frequency required for the transition between two adjacent quantum states is f i , such as the first quantum state (corresponding to the required excitation light frequency f1), the second quantum state (corresponding to the required excitation light frequency f2), and the third quantum state (corresponding to the required excitation light frequency f3). Therefore, the difference |l1-l2| in the orbital quantum number of the 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), and the difference in the magnetic quantum number is -1, 0 or 1.

[0090] As shown in FIG. 2, 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 a large adjustment of the laser frequency, which cannot be dynamically changed in operation or simulation, while 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 by 10 MHz. The polarization of the excitation light can be adjusted by a polarization electro-optical modulator, and the adjustment rate can reach the GHz level. The rapid fine-tuning of the excitation light frequency can be achieved by an acousto-optic modulator (AOM), and the adjustment rate can reach the 100 MHz level.

[0091] II. Ground state and Rydberg state of an atom

[0092] Since the interatomic interaction of the ground state neutral atom can be basically ignored, the atom needs to be excited from the ground state to the Rydberg state when transmitting information. Compared with the ground state atom, the electron cloud of the atom in the Rydberg state has multiple orders of magnitude increase, so that sufficient interatomic interaction force can be generated for the operation between multiple bits.

[0093] The interaction strength generally depends on the size of the electron cloud and the atomic distance R. The size of the electron cloud is determined by the principal quantum number n of the Rydberg state, and the interatomic interaction force is proportional to n 11 , and inversely proportional to R 6 .

[0094] The ground state of an atom refers to the quantum state with the lowest energy. Since a physical system tends to occupy a state with lower energy, the ground state is the most stable quantum state. Due to the symmetry of an atom, the atom usually has multiple quantum states with equal energy but different orbital quantum numbers. Quantum computing generally selects two different ground states with an orbital quantum number of zero as the computing ground state, and tends to select a ground state with a magnetic quantum number of zero to reduce the influence of environmental magnetic field noise on quantum state coherence.

[0095] Since the electron cloud of the ground state atom is quite small, the interatomic interaction force can be ignored, so only single-bit gate quantum bit manipulation process can be performed, and it is difficult to perform multi-bit gate quantum bit manipulation process. Therefore, when performing multi-bit logic gate or entanglement, the atom needs to be excited to a Rydberg state to obtain sufficient interatomic interaction force.

[0096] The Rydberg state generally refers to a highly excited state with a large principal quantum number. When the principal quantum number increases, the energy difference between adjacent energy levels decreases significantly, |E n -E n±1 |∝n -3 .

[0097] Taking a rubidium (Rb) atom as an example, FIG. 3 is a schematic diagram of the energy difference and dipole moment of the rubidium atom provided by the present application.

[0098] As shown in (A) and (B) of FIG. 3, when 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 ), and the dipole moment is proportional to For example, the energy difference from the principal quantum number n = 5 to 6 is 6 × 10 5 GHz, and the energy difference from n = 43 to 44 is only 100 GHz, that is, the energy difference decreases by three orders of magnitude. The dipole moment at n = 43 is about 400 times that at n = 5.

[0099] Combining the above two characteristics, as shown in (C) of FIG. 3, the interatomic interaction increases significantly with the principal quantum number, which is proportional to n 11 , and the strength of the interaction force is proportional to n 11 . The interatomic interaction at n = 43 is about 3 × 10 15 times that at n = 5. Even for atoms trapped in optical tweezers with a distance of several microns, there is sufficient interaction for multi-bit logic gate or entanglement.

[0100] In an embodiment of the present application, the commonly used parameter for the strength of the interaction force is C6, and the commonly used Rydberg state C6 is about 100 GHz / (μm) 6orders of magnitude. The Rydberg blockade effect is a necessary tool to realize a two-qubit logic gate, which refers to a physical phenomenon that when there are several atoms in a circle with a blockade radius as the radius, only one atom can be excited to a Rydberg state, and the excitations of other atoms are all suppressed. In experiments, the Rydberg blockade effect is often used to add an extra phase to the quantum state of the system, thereby realizing a theoretical entanglement gate.

[0101] III. Two-qubit gate.

[0102] In quantum computing theory, single-qubit rotations and two-qubit CZ gates form a basic set that can compile any quantum circuit. A conventional π-2π-π CZ gate scheme is shown in FIG. 4, which is a schematic diagram of a CZ gate provided by the present application, the CZ gate including a control atom (an atom corresponding to a control qubit, a black pattern in FIG. 4) and a target atom (an atom corresponding to a target qubit, a white pattern in FIG. 4). In some optional manners, the control qubit can also be referred to as an ancilla qubit, and the target qubit can also be referred to as a data qubit.

[0103] In the CZ gate scheme provided in FIG. 4, two addressing lasers act on the two atoms respectively, and the two lasers are both resonant with respect to the transition frequency between the |1> state and the Rydberg state |r> of the atom. A π pulse is first applied to the control atom, then a 2π pulse is applied to the target atom, and finally a π pulse is applied to the control atom.

[0104] In the CZ gate scheme shown in FIG. 4, if the two atoms are initially in the |00> state, the CZ gate has no interaction with the laser, and the CZ gate accumulates a phase shift of 0.

[0105] If the two atoms are initially in the |10> state, the control atom experiences a total of a 2π pulse and finally returns to the |1> state, and the CZ gate accumulates a phase of π; a π pulse from the |1> state to the |r> state, or from the |r> state to the |1> state.

[0106] If the CZ gate is initially in the |01> state, the target atom experiences a total of a 2π pulse and finally returns to the |1> state, and the CZ gate accumulates a phase of π.

[0107] If the CZ gate is initially in the |11> state, the control atom experiences a total of a 2π pulse and finally returns to the |1> state, and accumulates a phase of π, while the target atom is prevented from coupling with the laser and undergoing a transition due to the blockade effect of the control atom excited to the |r> state after the first π pulse, so the phase accumulation of the CZ gate is also π in this case.

[0108] In this scheme, the two-qubit gate evolution matrix with the basis {|00>, |01, |10>, |11>} is Diag{1, -1, -1, -1}, which is the same as the theoretically defined CZ gate.

[0109] By using atomic arrays of different components, crosstalk problems can be effectively improved. In the multi-component atomic system provided in the embodiments of the present application, atoms of different components can be used as data bits and auxiliary bits, respectively. Since atoms of different components have different energy level structures, the corresponding manipulation and detection light frequencies are also different, thereby avoiding crosstalk between adjacent atomic bits. The auxiliary bits can be used for detection of the data bits and information storage. By performing Rydberg excitation on the data bits and the auxiliary bits, interatomic interaction is generated between them, so that the quantum state of the data bits is transferred to a certain auxiliary bit, thereby achieving the effect of low-crosstalk information transfer between different quantum bits. When performing information transfer, a specific atomic pair is selected for Rydberg multi-bit operation to ensure that information is only transferred between specific atoms and crosstalk between adjacent atoms is avoided.

[0110] In the conventional technology, a quantum computing system irradiates and controls selected atoms by means of a highly focused light beam, and adjusts the interatomic interaction force by moving and arranging the atoms, which requires the atomic spacing to be on the order of several microns to enable a strong enough interatomic interaction force. This makes the light beam for addressing operation need to be focused to the order of one micron to reduce crosstalk to adjacent atoms that do not participate in the operation. However, due to the small beam waist of the light beam, the effective light intensity experienced by the atoms is highly sensitive to the position of the atoms and the thermal motion of the atoms. At the same time, since multi-bit gate operation requires irradiating multiple atoms simultaneously by means of addressing light, this further increases the sensitivity and limits the fidelity of information transfer.

[0111] To at least solve the above problems, the quantum computing system and the quantum computing method to which the embodiments of the present application can be applied will be described in detail below with reference to the accompanying drawings.

[0112] FIG. 5 is a structural schematic diagram of a quantum computing system provided by the present application. The quantum computing system 400 includes an atomic source 410, an atomic cavity 420, an optical tweezer unit 430, a global light emitter 442, and a quantum bit measurement unit 450. The atomic cavity 420 is connected to the atomic source 410.

[0113] Optionally, the quantum computing system 400 can further include a control system, such as a control system including a controller and a memory. The memory can 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 EPROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium well known in the art, etc.

[0114] The controller can be used to control various components in the quantum computing system 400 according to information to be calculated. For example, the controller can be a processor, such as a central processing unit (CPU), an application-specific integrated circuit (ASIC) implementation, or a programmable logic device (PLD), which can be a complex programmable logical device (CPLD), a field programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. For another example, the processor can also be a digital signal processor (DSP) or other programmable logical device, transistor logical device, hardware component, or any combination thereof. In the present embodiment, the controller can be a microprocessor or any conventional processor.

[0115] The quantum computing method provided in this embodiment can include the following steps: the atom source 410 is configured to provide a plurality of types of atoms, and the atom cavity 420 is configured to store the atoms provided by the atom source 410, the atoms provided by the atom source 410 include a plurality of first atoms representing data bits and a plurality of second atoms representing auxiliary bits, the auxiliary bits are configured to temporarily store information corresponding to the data bits. The optical tweezer unit 430 is configured to generate a plurality of optical tweezers in the atom cavity 420, and arrange the optical tweezers in which the atoms in the atom cavity 420 are captured according to the first information to obtain an atom array. The atom array includes a group of second atoms representing the auxiliary bits and target first atoms corresponding to the data bits paired with the auxiliary bits, the group of second atoms includes one or more target second atoms, the target first atoms and the group of second atoms are located in different layers, and an axis formed by the target first atoms and the group of target second atoms is perpendicular to the layer containing the group of second atoms, and the ratio between the first distance and the second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the group of second atoms and another group of target second atoms adjacent to the group of target second atoms, and the second distance is a distance between the group of target second atoms and the target first atoms. The global light emitter 442 is configured to generate global light according to the second information, the global light is configured to irradiate the atom array, so that the information corresponding to the data bits corresponding to the target first atoms is transmitted to the auxiliary bits represented by the group of second atoms. The quantum bit measurement unit 450 is configured to collect scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by a probe light beam, and determine the quantum computing result of the first information and the second information according to the scattered photons.

[0116] The components of the quantum computing system 400 and the specific process of the quantum computing method will be described in detail below with reference to the accompanying drawings.

[0117] The atom source 410 provides a plurality of types of atoms. For example, the atoms provided by the atom source 410 can include but are not limited to the following types of atoms: alkali metal atoms such as lithium, sodium, potassium, rubidium, cesium, or alkaline earth metal atoms such as beryllium, magnesium, calcium, strontium, barium, and radium. The difference between the alkali metal atoms and the alkaline earth metal atoms is that the alkali metal atoms each have one outermost electron belonging to an s orbital, and the alkaline earth metal atoms each have two outermost electrons belonging to an s orbital.

[0118] As an optional implementation manner, the atom cavity 420 includes a glass cavity and a vacuum structure.

[0119] For example, the glass cavity can withstand a vacuum environment in its cavity. For example, the glass cavity includes a first connecting member and a cavity structure. For example, the vacuum structure can be a vacuum pump or other components or devices for generating a vacuum environment, which are not limited in the present application.

[0120] As a possible specific example, the glass cavity described above includes: a first connecting member and a cavity structure, the first connecting member is detachably connected with the vacuum structure and the first hole structure. The first connecting member is connected with the atom source 410, and the cavity structure is provided with the first hole structure. For example, the first hole structure penetrates the inner wall and the outer wall of the cavity structure.

[0121] For example, if the cavity structure is connected with the vacuum structure through the first hole structure, the vacuum structure is used to extract background gas molecules in the cavity structure, so that the cavity structure is in a vacuum state. In this example, the center of the quantum computing system can be a vacuum glass cavity connected with a vacuum pump to maintain an ultra-high vacuum environment in the glass cavity to suppress the collision of atomic qubits with background gas molecules in the cavity, thereby improving the trapping time and coherence time of atoms in the atomic cavity. The vacuum system also provides an atom source for providing atomic qubits used by the system.

[0122] The above glass cavity and vacuum structure are only possible implementations of the atomic cavity 420 provided in the embodiment and should not be construed as a limitation of the present application. In other alternative implementations, the glass cavity can also be replaced by other cavities capable of carrying a vacuum environment in its cavity, which is not limited by the present application.

[0123] In the embodiment, the atomic cavity 420 is used to store atoms provided by the atom source 410, and the atoms provided by the atom source 410 include first atoms and second atoms.

[0124] For the loading mode of the first atoms and the second atoms in the atomic array, a possible implementation is provided below in combination with FIG. 6A, which is a loading schematic diagram of an atomic array provided by the present application.

[0125] In the atomic array shown in (1) of FIG. 6A, a group of second atoms used to represent auxiliary bits includes one or more target second atoms (such as atom 5), a target first atom (t atom), and the target second atom (atom 5) is located in a different layer from the target first atom (t atom), and the axis formed by the target first atom (t atom) and the group of second atoms (atom 5) is perpendicular to the layer containing the group of second atoms (atom 5), and the ratio between the first distance and the second distance is a reference value, the first distance is the lateral distance (dx) or the longitudinal distance (dy) between the group of second atoms (atom 5) and another group of target second atoms adjacent to the group of second atoms (atom 5), and the second distance is the distance (dz) between the group of second atoms (atom 5) and the target first atom (t atom).

[0126] On the basis of FIG. 6A, the first distance and the second distance are exemplarily illustrated in combination with FIG. 6B, which is a schematic diagram of the first distance and the second distance provided by the present application, the first atom and the second atom are located in different layers, the first distance (dx) is the distance between atom 5 and atom 6, and the second distance (dz) is the distance between the t atom and atom 5.

[0127] In (1) of FIG. 6A, different component atoms are respectively trapped in two-dimensional optical arrays, and two two-dimensional atom arrays (an atom array corresponding to the first atom and an atom array corresponding to the second atom) are aligned on the z axis and arranged at intervals (dx, dy, dz). As shown in (1) of FIG. 6A, the atom array uses a multi-component multi-layer atom arrangement, and the auxiliary bit (atom 5) is arranged below the paired data bit (target first atom or t atom) and arranged at intervals (dx, dy, dz). Wherein, dx is the physical distance between atom 5 and atom 6, dy is the physical distance between atom 5 and atom 2, and dx is the physical distance between the t atom and atom 5.

[0128] By selecting a suitable combination of Rydberg states, the interaction force between atoms of the same component (data bit and data bit, or auxiliary bit and auxiliary bit) can be made much smaller than the interaction force between atoms of different components (data bit and auxiliary bit). At the same time, by controlling the frequency and polarization of the Rydberg excitation light (such as the global light described above), the interaction force between atoms of different components can be made to have strong directionality, as shown in (2) and (3) of FIG. 6A.

[0129] In (2) of FIG. 6A, the strength of the interaction force between atoms of different components varies with the angle θ according to the formula (1-3(cosθ) 2 ) / 2. The strength of the interaction force between atoms of different components is zero at the magic angle θ0.

[0130] In (3) of FIG. 6A, the strength of the interaction force between atoms of different components is zero at the position corresponding to the reference angle θ. In some optional cases, the reference angle θ can also be referred to as a magic angle, a configuration angle, or other names, which are not limited by the present application.

[0131] The θ shown in (2) and (3) of FIG. 6A is exemplarily illustrated in combination with formula 1: the strength of the interaction force between atoms of different components varies with the angle θ according to the formula (1-3(cosθ) 2 ) / 2. As shown in FIG. 6A, when d x =d y and d z satisfy the relationship The strength of the interaction force between the t atom and its second nearest neighbor atom 2 will be zero or a minimum value relative to the strength of the interaction force between the nearest neighbor atom 5. The atom 3 located in the second nearest neighbor of the t atom is not at the zero angle, but due to the interaction force ∝1 / R6 So the equivalent strength is close to zero (see equation 1 below), so it can be considered as no interaction.

[0132] Wherein, atom 5 is the nearest neighbor atom of the t atom, atom 2 is the next nearest neighbor atom of the t atom, and atom 3 is the next next nearest neighbor atom of the t atom.

[0133] As shown in (2) and (3) of FIG. 6A, the innovation of the embodiments of the present application is that by selecting appropriate (dx, dy, dz), the next nearest neighbor inter-component interaction can be eliminated while the nearest neighbor inter-component interaction is retained, using the directionality of the inter-component interaction. Even if global Rydberg excitation light (global light) is used, the data bit will only interact with the paired auxiliary bit. Without causing crosstalk to other bits, the information is transmitted from the data bit (t atom) to the auxiliary bit (atom 5).

[0134] It is worth noting that tanθ above is the reference value (K) provided by the embodiments of the present application, which can also be referred to as a loading reference value, a loading characteristic value, or a magic value, etc., which is not limited in the present application.

[0135] For example, the reference angle θ can also have other values, such as 54.7°±N°, where N is 1, 2, 3, 4, 5, or other values. In this way, the value of The value of tanθ provided by the embodiments of the present application can be different according to the change of the magic angle θ.

[0136] In an optional example, it is assumed that N is 2, i.e., the value range of θ is [52.7°, 56.7°], i.e., the minimum value of θ is 52.7° and the maximum value of θ is 56.7°. Compared with the case where the value of θ is 0° and the inter-component interaction force is the maximum value, in the case where the value of θ is 52.7° or 56.7°, the inter-component interaction force (inter-component atomic interaction force) is about 5% of the maximum value. The 5% is only an optional value provided in this example, and the change of the inter-component interaction force can be different according to the change of different hardware in the quantum computing system and the type of atoms in the atomic cavity.

[0137] In another optional example, it is assumed that N is 5, i.e., the value range of θ is [49.7°, 59.7°], i.e., the minimum value of θ is 49.7° and the maximum value of θ is 59.7°. Compared with the case where the value of θ is 0° and the hetero-component interaction force is the maximum value, in the case where the value of θ is 49.7° or 59.7°, the hetero-component interaction force (the interatomic interaction force of the hetero-component) is about 10% of the maximum value. The 10% is only an optional value provided in this example, and the change of the hetero-component interaction force may be different according to the change of different hardware in the quantum computing system and the difference of the atom type in the atomic cavity.

[0138] The above describes the value of the reference angle θ in combination with different examples, and the value of the reference angle θ and the reference value K can also change according to the change of the hardware in the quantum computing system and the difference of the atom type, which is not limited in the present application.

[0139] In some optional cases, the atoms provided by the atom source 410 can also include other types of atoms, such as a third atom.

[0140] For example, the first atom can be a rubidium atom (Rb) and the second atom can be a ytterbium atom (Yb), or the first atom can be a ytterbium atom (Yb) and the second atom can be a rubidium atom (Rb). It should be noted that the first atom and the second atom can also be other atoms, which are not limited in the present application.

[0141] In the present embodiment, the Rydberg state of the first atom includes a first Rydberg state and a second Rydberg state, the first Rydberg state corresponds to a first value of the magnetic quantum number of the first atom, and the second Rydberg state corresponds to a second value of the magnetic quantum number of the first atom.

[0142] In addition, the Rydberg state of the second atom includes a third Rydberg state and a fourth Rydberg state, the third Rydberg state corresponds to a third value of the magnetic quantum number of the second atom, and the fourth Rydberg state corresponds to a fourth value of the magnetic quantum number of the second atom.

[0143] The energy difference (energy difference) of the magnetic quantum number of different types of atoms and the corresponding Rydberg state is described below in combination with the drawings. As shown in FIG. 7, FIG. 7 is a schematic diagram of the transition of the Rydberg state of different atoms provided by the present application. It is assumed that the first atom is an α atom and the second atom is a β atom, and the interatomic distance between the α atom and the β atom can be represented by R.

[0144] The first Rydberg state is the Rydberg state in FIG. 7 The adjacent Rydberg state of the first Rydberg state is

[0145] The second Rydberg state is the Rydberg state in FIG. 7 The adjacent Rydberg state of the second Rydberg state is

[0146] The third Rydberg state is the Rydberg state in FIG. 7 The adjacent Rydberg state of the third Rydberg state is

[0147] The fourth Rydberg state is the Rydberg state in FIG. 7 The adjacent Rydberg state of the fourth Rydberg state is

[0148] The energy difference between the first Rydberg state and its adjacent Rydberg state is a first energy value, the energy difference between the second Rydberg state and its adjacent Rydberg state is a second energy value, the energy difference between the third Rydberg state and its adjacent Rydberg state is a third energy value, and the energy difference between the fourth Rydberg state and its adjacent Rydberg state is a fourth energy value.

[0149] As an optional embodiment, the difference (energy difference) between the energy of the Rydberg state of the first atom and its adjacent Rydberg state and the energy of the Rydberg state of the second atom and its adjacent Rydberg state is less than an energy threshold value.

[0150] For example, the difference (energy difference) between the first energy value and the third energy value is less than the energy threshold value.

[0151] For another example, the difference (energy difference) between the first energy value and the fourth energy value is less than the energy threshold value.

[0152] For yet another example, the difference (energy difference) between the second energy value and the third energy value is less than the energy threshold value.

[0153] For still another example, the difference (energy difference) between the second energy value and the fourth energy value is less than the energy threshold value.

[0154] In the present example, the energy difference above is also referred to as the energy defect of the different types of atoms in the transition process. For example, the interatomic interaction force V(R) between the α atom and the β atom can be obtained according to the following formula 2.

[0155] wherein, Δ=E bd -E ac Δ refers to the energy defect of the channel (such as the difference between the first energy value and the third energy value) in the transition process. The dipole interaction of the single channel has the characteristics of fast adjustment and strong directivity. In order to isolate and highlight the dipole interaction of the single channel, the dipole interaction of the single channel is set to be zero in the present example. ​​The channel can be formed by using a two-component system and selecting a proper combination of principal quantum number and orbital quantum number. For example, in the case of rubidium atoms and ytterbium atoms, the energy difference between each of the rubidium and ytterbium atoms and the adjacent Rydberg state varies with the principal quantum number. In a two-component atomic system or a multi-component atomic system, there are multiple combinations of principal quantum numbers that can make .

[0156] As an optional implementation, the above combination of principal quantum numbers can be determined by selecting the principal quantum number (n Rb ) of the rubidium atom and the principal quantum number (n Yb ) of the ytterbium atom, and adjusting the energy difference between n Rb , n Yb and the adjacent Rydberg state to make .

[0157] Based on the quantum properties of atoms, the strength of the interatomic force varies with the angle of the quantization axis in multiple different forms. FIG. 8 shows three interatomic forces provided by the present application.

[0158] In example 1 shown in FIG. 8, the force along the up-down direction is larger, and the force along the left-right direction is smaller, i.e., the dipole force along the up-down direction is strong, and the interatomic force has strong directionality along the up-down direction.

[0159] In example 2 shown in FIG. 8, there is no force along the up-down direction, and the force along the left-right direction is larger, i.e., the dipole force along the left-right direction is strong, and the interatomic force has strong directionality along the left-right direction.

[0160] In example 3 shown in FIG. 8, the force along the left-down-right-up direction is larger, and the force along the left-up-right-down direction is larger, i.e., the interatomic force has strong directionality along the left-down-right-up and left-up-right-down directions.

[0161] The above three examples are provided for the implementation of the present embodiment, and should not be construed as a limitation of the present application. In general, the three interatomic forces shown in FIG. 8 are mixed with each other, so that the interatomic force in the atomic array loses strong directionality.

[0162] In order to make the interatomic interaction force have strong directionality, so as to effectively control the interatomic interaction force in different directions, the embodiment of the present application provides an optional implementation manner: selecting a suitable orbital quantum number, breaking the spatial symmetry of the transition between adjacent Rydberg states, thereby strengthening the directionality of the interatomic interaction force, so as to improve the accuracy of quantum computing. For more details about the orbital quantum number, please refer to the description of the strong directionality in the following (three), quantum state preparation and manipulation (manipulation), which will not be repeated here.

[0163] Please continue to refer to FIG. 5. The optical tweezer unit 430 provided by the embodiment is configured to generate a plurality of optical tweezers in the atomic cavity 420, and arrange the optical tweezers in the plurality of optical tweezers that have captured the atoms in the atomic cavity 420 in a first manner to obtain an atomic array. Exemplarily, the optical tweezer unit 430 can include, but is not limited to, one or both of a light source, a spatial light modulator (SLM) or an acousto-optic deflector (AOD). The light source is configured to provide trapping light, and the SLM and the AOD are configured to generate an optical tweezer array.

[0164] It is worth noting that since the optical tweezers generated by the optical tweezer unit 430 are used to capture atoms, in some examples, the light beams forming the optical tweezers can also be referred to as static optical tweezer array light (beams) in the quantum computing process.

[0165] Based on the atomic array described above, the quantum computing system can implement a quantum computing process between data and data (or information and information). As shown in FIG. 9A, FIG. 9A is a schematic diagram of an information control process and a quantum computing process provided by the present application.

[0166] As shown in FIG. 9A, the information control process includes: step 1, designing an applicable atomic array arrangement relationship and a quantum bit logic gate (referred to as a quantum gate or a logic gate) according to a target problem; step 2, designing an applicable quantum array combination (for details, please refer to the content of the foregoing embodiment); step 3, adjusting the optical parameters of the light beams in the quantum computing process; step 4, determining whether to adjust the optical parameters in the quantum computing process, if yes, returning to execute step 3; if no, ending the information control process. For the content of steps 3 and 4, please refer to the description of the following (three), quantum state preparation and manipulation (manipulation), which will not be repeated here. The quantum computing process generally includes the following four processes: (one), preparation and cooling of atomic magneto-optical traps; (two), loading and rearrangement of atomic arrays; (three), quantum state preparation and manipulation (manipulation); (four), information transmission; (five), quantum state reading. The following will be exemplarily described in combination with the accompanying drawings.

[0167] (one), preparation and cooling of atomic magneto-optical traps.

[0168] Figure 9B is a schematic diagram of loading of the optical tweezers and the atomic array provided by the present application. In (a) of Figure 9B, a plurality of atoms stored in the atomic cavity form an atomic cloud, and the atoms in the atomic cloud are collected to the center of the magnetic field of the atomic cavity after being cooled by the laser. Meanwhile, the atomic cavity also includes a plurality of optical tweezers generated by the optical tweezers unit 430, and the plurality of optical tweezers form an optical trap as shown in (b) of Figure 9B. In (b) of Figure 9B, the optical trap corresponds to a 4x4 optical tweezers array, i.e., the atomic cavity includes 16 optical tweezers for capturing atoms. Since the optical tweezers array is used to capture the atomic cloud located at the center of the magnetic field, in some cases, the optical trap is also referred to as an atomic magnetic optical trap or a magnetic optical trap in the atomic cavity.

[0169] In the present embodiment, each optical tweezers can be used to capture one or more atoms.

[0170] In one possible example, one optical tweezers is used to capture one atom.

[0171] In another possible example, one optical tweezers is used to capture a plurality of atoms, such as two, three, five or other quantities, etc.

[0172] The number of atoms that can be captured by each optical tweezers and the atomic spatial density, the spatial range covered by the optical tweezers are related.

[0173] The process of capturing atoms by the optical tweezers (loading and rearrangement of the atomic array) is exemplarily illustrated below in connection with (c) of Figure 9B.

[0174] (ii) Loading and rearrangement of the atomic array.

[0175] As shown in (c) of Figure 9B, due to the randomness of the process of loading atoms by the optical tweezers, only part of the optical tweezers in the magnetic optical trap (optical trap) can be loaded with atoms, resulting in a random distribution of the arrangement of the atoms in the optical tweezers array. In order to enable each atom in the atomic cavity to meet the requirements of quantum computing, the atoms in the atomic cavity need to be rearranged according to the operation problem (such as quantum simulation, data calculation, etc.) to be solved by the quantum computing.

[0176] Optionally, the controller in the quantum computing system can determine the arrangement of each atom in the atomic cavity according to the input information to be calculated.

[0177] For example, as shown in the information control process in Figure 9A, the input information to be calculated includes first information and second information. The first information is used to determine the arrangement relationship of the optical tweezers in the atomic cavity that capture different types of atoms, and the second information is used to determine the light parameters (such as beam direction, frequency and polarization, etc.) of the excitation light required for manipulating the quantum state.

[0178] In some possible manners, the first information is determined according to a target problem to be solved by the quantum computing system. For example, in the information control process of FIG. 9A, an applicable atomic array arrangement relationship is designed according to the target problem, which is used to determine the first information, and a quantum bit logic gate (referred to as a quantum gate or a logic gate) is designed according to the target problem, which is used to determine a quantum combination (a principal quantum number, an orbital quantum number, and a magnetic quantum number) to be adopted in the embodiment. The content of the quantum combination can refer to the description of FIG. 7, which is not repeated here.

[0179] In the embodiment, the controller controls the optical tweezer unit 430 according to the first information to arrange the atoms of different types captured in the magneto-optical trap in the first manner to obtain the atomic array, as shown in the atomic array in FIG. 5. In FIG. 5, the white circular pattern in the atomic array is the first atom, and the black circular pattern is the second atom.

[0180] Optionally, the data amount of the first information is associated with a bit width of a quantum bit that can be represented by the atomic array. For example, the bit width of the quantum bit that can be represented by the atomic array is greater than or equal to the data amount of the first information.

[0181] In a first optional case, the bit width of the quantum bit that can be represented by the atomic array is greater than the data amount of the first information. For example, the bit width of the quantum bit that can be represented by the atomic array is 10 bits, and the data amount of the first information is 9 bits, 8 bits (1 byte), or the like.

[0182] In a second optional case, the bit width of the quantum bit that can be represented by the atomic array is equal to the data amount of the first information. For example, the bit width of the quantum bit that can be represented by the atomic array is 10 bits, and the data amount of the first information is 10 bits.

[0183] The above two possible cases are only examples of the bit width of the quantum bit that can be represented by the atomic array provided in the embodiment, and should not be understood as a limitation on the present application. In some optional cases, one atomic array can be used to represent a quantum bit with a smaller or larger bit width, such as 4 bits, 2 10 bits, 2 20 bits, 2 100 bits, 10 10 bits, or the like.

[0184] In order to more accurately manipulate different types of atoms in the atomic cavity, different wavelength ranges of optical tweezers can be used to capture and manipulate different types of atoms. For example, the wavelengths of the optical tweezers in FIG. 9B are different, and the optical tweezers in the first wavelength range are used to capture the first atoms, and the optical tweezers in the second wavelength range are used to capture the second atoms. In the embodiments of the present application, during the loading and rearrangement of the atomic array, different wavelength optical tweezers are used to interleave two different components of atoms, so that the rearranged atomic array meets the requirements of quantum computing.

[0185] As shown in (c) and (d) of FIG. 9B, (c) is that only part of the optical tweezers capture atoms, and each optical tweezers is randomly arranged; (d) is an atomic array obtained after rearrangement of randomly arranged atoms. In some cases, the atomic array shown in (d) is also referred to as a defect-free atomic array.

[0186] In this way, different wavelength ranges of optical tweezers are used to capture different types of atoms, which avoids the problem that the arrangement of the atomic array is disordered when the same wavelength range of optical tweezers is used to capture different types of atoms, and is conducive to improving the accuracy of quantum computing. Moreover, different optical tweezers are used to capture different atoms, which avoids the problem of crosstalk between different components of atoms, and improves the fidelity of the atomic array and the accuracy of quantum computing.

[0187] The loading method of the atomic array in the embodiments of the present application can refer to the foregoing FIG. 6A, and will not be described here.

[0188] (Three), quantum state preparation and manipulation (control).

[0189] In the embodiments of the present application, when the quantum computing system prepares the atomic array, the initial states of the ancillary bits are all in the 0 state. In order to manipulate the quantum state of the data bit, the global light is used to couple the 1 state and the Rydberg state of the data / ancillary bit, and has no effect on the 0 state.

[0190] The atoms in the atomic array can be operated by the global light or the microwave to perform parallel logic gate operation on all atoms. The addressing manipulation light is focused to a specific array position through the objective lens, and can be used to independently manipulate the selected atoms. Since different components of atoms have different energy level structures, the corresponding manipulation and detection light frequencies are also different, and different components of atoms can be operated without crosstalk.

[0191] (Four), information transfer.

[0192] The following will be exemplarily described with reference to FIG. 5 and FIG. 6A. The global light emitter 442 generates global light according to the second information, and the global light is used to irradiate the atomic array, so that the information corresponding to the data bit corresponding to the target first atom (such as the t atom in the foregoing FIG. 6A) is transferred to the ancillary bit represented by a group of second atoms (such as the atom 5 in the foregoing FIG. 6A).

[0193] In the embodiments of the present application, the role of the auxiliary bit is to eliminate the next nearest neighbor hetero-component interaction force by using the directionality of the interatomic interaction force while preserving the nearest neighbor hetero-component interaction force at a specific atomic arrangement distance. Even if global Raman light is used, the data bit will only interact with the paired auxiliary bit. Without crosstalk to other bits, the information is transmitted from the data bit to the auxiliary bit, avoiding the need for addressing light or moving atoms in the conventional scheme.

[0194] For the specific implementation of the global light, the following takes an example in which the global light includes a first polarized light beam and a second polarized light beam. The embodiments of the present application provide a possible example: the global light emitter 442 generates a first polarized light beam in a first direction and a second polarized light beam in a second direction according to the second information, and irradiates the atomic array generated by the loading and rearrangement of the aforementioned (ii) atomic array with the first polarized light beam and the second polarized light beam.

[0195] The first frequency of the first polarized light beam and the first direction correspond to the first Rydberg state or the second Rydberg state. Illustratively, the first polarized light beam is used to excite the first atom to the first Rydberg state or the second Rydberg state. For example, in the case where the first atom is in the ground state, after the first polarized light beam irradiates the first atom, the quantum state of the first atom changes to the first Rydberg state or the second Rydberg state.

[0196] The second frequency of the second polarized light beam and the second direction correspond to the third Rydberg state or the fourth Rydberg state. Illustratively, the second polarized light beam is used to excite the second atom to the third Rydberg state or the fourth Rydberg state. For example, in the case where the second atom is in the ground state, after the second polarized light beam irradiates the second atom, the quantum state of the second atom changes to the third Rydberg state or the fourth Rydberg state.

[0197] In the quantum computing scenario, since the purity of the polarization of the light beam has a great influence on the fidelity of the quantum bit logic gate, there needs to be a suitable angle between the two light paths (the first polarized light beam and the second polarized light beam) to improve the fidelity of the quantum bit logic gate represented by the atomic array in the atomic cavity 420. Illustratively, the angle between the two light paths can be determined according to the confidence requirement of quantum computing. For example, if the confidence requirement is high, the angle between the two light paths is larger; and for example, if the confidence requirement is low, the angle between the two light paths is smaller.

[0198] As a possible example, the angle between the first polarized light beam and the second polarized light beam is 90°. During quantum computing, by changing the angle of the two polarized light beams, the Rydberg state of the atom corresponding to the polarized light beam can be manipulated to make the atomic array represent different quantum bits.

[0199] For the process of generating and adjusting the polarized light beams, based on the global light emitter 442 shown in FIG. 5, the embodiments of the present application provide a possible implementation, as shown in FIG. 10, which is a schematic structural diagram of a quantum computing system provided by the present application. The global light emitter 442 includes an excitation light source 442a and a light path modulation component 442b, and the excitation light source 442a and the light path modulation component 442b are connected.

[0200] The excitation light source 442a is configured to generate an illumination light beam for illuminating the atomic array in the atomic cavity 420.

[0201] The light path modulation component 442b is configured to process the light parameters of the illumination light beam according to the second information to obtain a first polarized light beam in a first direction and a second polarized light beam in a second direction. The light parameters include one or a combination of the following: light beam direction, polarization, and frequency. The light beam direction is used to indicate the physical direction of the light path of the light beam during propagation. The descriptions of polarization and frequency can be referred to the description of technical terms in the specific embodiments, which will not be repeated here.

[0202] The light path modulation component 442b can be implemented in one or more different ways to control the light parameters of the illumination light beam. Three possible implementations of the light path modulation component 442b are provided below in combination with FIG. 10, which is an implementation schematic diagram of the light path modulation component provided by the present application.

[0203] In the first implementation (way 1 in FIG. 11), the light path modulation component 442b includes a light splitter and an acousto-optic modulator (AOM). The AOM is configured to divide the illumination light beam into a first light beam of a first frequency and a second light beam of a second frequency, and the light splitter is configured to adjust the direction of the first light beam to the first direction to obtain the first polarized light beam, and adjust the direction of the second light beam to the second direction to obtain the second polarized light beam.

[0204] In a possible case, the AOM above can also be replaced by an AOD or other optical devices that can be used to adjust the frequency and polarization. In the adjustment process of the light beam, the adjustment order of the light beam direction and the frequency can also be changed, such as first adjusting the frequency of the illumination light beam by the AOD, and then adjusting the direction of the light beam by the light splitter. That is, in the embodiments of the present application, the adjustment order of each light parameter can be changed according to the physical position of the light path modulation component in the quantum computing system or the priority of the light parameter in the light path (manually set or system default), which is not limited in the present application.

[0205] Thus, the AOM is used to adjust the frequency of the light beams, and the beamsplitter is used to adjust the incident angle (the direction of the light beams) of the light beams, so that the two adjusted polarized light beams can be used to manipulate the quantum states in the atomic cavity, so that each atom in the atomic array is excited to a different Rydberg state, and then the interatomic interaction force of different atoms in the atomic array is controlled, the opening or closing of the quantum bit logic gate is realized, and the quantum computing process is completed.

[0206] In addition, the embodiment of the present application selects appropriate Rydberg state combinations, so that the range of the frequency of the light required to change the magnetic quantum number of the atom is small, and thus the range of the frequency of the light required to control the transition between the Rydberg states of different types of atoms in the quantum computing system is reduced, and the AOM or the AOD can also meet the requirement of quickly adjusting the range of the frequency of the light, which is beneficial to quickly adjusting the quantum state of the atomic array, so as to improve the speed and efficiency of the quantum computing.

[0207] In the second implementation manner (way 2 in FIG. 11), the optical path modulation component 442b includes an electro-optic modulator (EOM) and a polarization beamsplitter (PBS). The EOM is configured to process the illumination light beam to obtain first and second illumination sub-beams with different polarizations. The PBS is configured to adjust the direction of the first illumination sub-beam to the first direction to obtain the first polarized light beam, and adjust the direction of the second illumination sub-beam to the second direction to obtain the second polarized light beam.

[0208] Thus, the embodiment of the present application provides two non-collimated excitation light paths (the first polarized light beam and the second polarized light beam), and the optical path modulation component is used to change the direction, polarization and frequency of the light beams, so as to control the transition between different Rydberg states of the atoms, change the magnetic quantum number of different types of atoms, and facilitate the implementation of the quantum computing process based on the quantum bits.

[0209] In the third implementation manner (way 3 in FIG. 11), the optical path modulation component 442b includes a digital micromirror device (DMD). The DMD is configured to determine the light parameters to be used according to the second information, and process the illumination light beam according to the light parameters to be used to obtain the first and second polarized light beams. The DMD is a kind of optical switch, and the rotation mirror is used to realize the opening and closing of the optical switch, and the opening and closing time is in the order of microseconds. The principle of the DMD includes that the light beam is incident on the mirror of the DMD. When the DMD is opened, the light beam can pass through the symmetric optical path and enter the one-end optical fiber. When the DMD is closed, that is, the mirror of the DMD is rotated slightly, the light beam is reflected and transmitted to another direction. If the optical path of the other direction is closed, the effect of the closed optical switch is realized.

[0210] The above three implementation manners are only examples of the optical path modulation assembly provided by the embodiments of the present application, and should not be construed as a limitation of the present application. For example, the device for splitting light is not limited to a beam splitter, a PBS, or a DMD, and can also be other fast light splitting assemblies capable of achieving the function of splitting light. In some optional cases, the above three implementation manners can be used alone, or can be used partially or wholly in combination.

[0211] For the optical path of the illumination light beam, assuming that the above three implementation manners are used in combination, on the basis of FIGS. 10 and 11, FIG. 12 provides a possible example, which is a schematic diagram of rapidly changing optical parameters according to the present application. In FIG. 12, the frequency of the light beam can be rapidly modulated by adjusting the radio frequency signal of the AOM or the EOM; and the polarization of the light beam needs to be adjusted by the fast light splitting assembly to change the incident direction of the light beam, for example, the included angle between the two polarized light beams is 90°.

[0212] In the embodiments of the present application, the adjustment of the interatomic interaction force requires rapid change of the Rydberg state of the atom, and the Rydberg state of the atom is changed by rapidly adjusting the frequency, direction, and polarization of the light beam. The rapid adjustment of the laser frequency can be achieved by adjusting the radio frequency signal of the AOM or the EOM, and the adjustment of the excitation light polarization needs to change the incident direction of the excitation light. Since the frequency required to adjust the magnetic quantum number (100 MHz) is much smaller than the frequency required to adjust the principal quantum number (10 GHz), the adjustment of the quantum number is also shortened from the millisecond level to the nanosecond level, effectively improving the adjustment rate of the interatomic interaction force and facilitating the improvement of the efficiency of quantum computing.

[0213] In the process of quantum computing, the polarization of the light beam and the advancing direction of the light beam are also related to the angle of the quantization axis in the atomic cavity 420, and the direction of the quantization axis is determined by the magnetic field generated by the coil wrapped around the atomic cavity 420. Therefore, in order to improve the strong directionality of the interatomic interaction force, the quantization axis can also be adjusted by adjusting the size and direction of the magnetic field to change the direction of the interatomic interaction in the atomic array.

[0214] In order to further strengthen the strong directionality of the interatomic interaction force in the atomic array, the embodiments of the present application can also enhance the single dipole moment force by controlling the orbital quantum number. In combination with the related content of the foregoing FIG. 8, the implementation manner of selecting the orbital quantum number according to the embodiments of the present application includes the following three possible cases.

[0215] In the first possible case, the orbital quantum number of the first atom corresponding to the first Rydberg state and the second Rydberg state is not zero. In this way, the first atom has a single direction of the dipole moment force in the atomic array, such as the example 1 or the example 2 in FIG. 8. It should be understood that the single direction is not limited to the up-down direction or the left-right direction, and can also be other directions, which are not limited by the present application.

[0216] In a second possible case, the orbital quantum number of the second atom corresponding to the third and fourth Rydberg states is not zero. In this way, the second atom has a single direction of dipole moment force in the atomic array, such as example 1 or example 2 in FIG. 8. It should be understood that the single direction is not limited to the up-down direction or the left-right direction, but can also be other directions, which are not limited herein.

[0217] In a 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.

[0218] As an optional implementation, in the atomic array provided in the above embodiments, the interatomic interaction between two adjacent atoms of the same type is smaller than the interatomic interaction between two adjacent atoms of different types. In this way, the hetero-component interaction strength changes by an order of magnitude with the angle, which can achieve the effect of opening or closing the quantum bit logic gate in a specific direction.

[0219] In a possible specific example, the quantum computing system can select the quantum state (Rydberg state) or the spatial arrangement of the atoms (the arrangement of the atomic array) so that the interaction between the homocomponents is much smaller than the interaction between the heterocomponents, thereby equivalent to closing the logic gate between the homocomponents, to achieve the opening or closing of the quantum bit logic gate in a specific direction.

[0220] For example, the atoms in the atomic array can be operated by a parallel logic gate (multi-qubit logic gate, multi-bit logic gate) through a polarized light beam in different directions. When the polarized light beam is used to manipulate all the atoms in the atomic array, the polarized light beam is also called global addressing light or global light, such as the global light in the above embodiments. As shown in (2) and (3) of FIG. 6A, by selecting a suitable (dx, dy, dz), the next nearest neighbor hetero-component interaction can be eliminated while the nearest neighbor hetero-component interaction is retained, by using the directionality of the interaction. Even if the global Rydberg excitation light (global light) is used, the data bits will only interact with the paired auxiliary bits. Without crosstalk to other bits, the information is transmitted from the data bits (t atoms) to the auxiliary bits (atom 5).

[0221] (Five), quantum state reading.

[0222] In combination with the content shown in FIG. 5, the above quantum bit measurement unit 450 is used to collect the scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by the probe light beam, and determine the quantum computing results of the first information and the second information according to the scattered photons.

[0223] It is worth noting that since the light beam used by the embodiments of the present application is global light rather than addressing light, the sensitivity to the position of atoms and atomic thermal motion is greatly reduced, and the information transmission fidelity is improved. At the same time, since the number of atoms in the ensemble auxiliary bit (the auxiliary bit represented by a plurality of second atoms) is larger, a small number of lost atoms in the detection process do not need to be reloaded each time and will not affect the detection, thereby improving the detection efficiency.

[0224] With regard to the implementation of the qubit measurement unit 450, an alternative example is provided based on FIG. 6A, as shown in FIG. 13, which is a structural schematic diagram III of a quantum computing system provided by the present application. The components already known in the foregoing embodiments are not described here again. The qubit measurement unit 450 in FIG. 13 includes an atomic probe 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.

[0225] The atomic probe light source 451 is configured to provide a probe light beam for illuminating the atomic array. In some possible cases, the probe light beam can also be referred to as a detection light beam of the qubit.

[0226] The objective lens 452 is configured to collect scattered photons generated by the atomic array after being illuminated by the probe light beam. In FIG. 13, the qubit measurement unit 450 includes two objective lenses 452, but this is only an example provided by the embodiments of the present application and should not be construed as a limitation to the present application. The qubit measurement unit 450 can also include only one objective lens or a larger number of objective lenses to achieve the collection of the scattered photons described above.

[0227] The photoelectric conversion unit 453 is configured to perform photoelectric conversion on the scattered photons collected by the objective lens 452 to output an electrical signal, which indicates the qubit in the atomic array, such as a voltage or a current. In some possible cases, the photoelectric conversion unit 453 can include a camera and a photoelectric signal processing module. For example, the camera is configured to perform fluorescence imaging on the scattered photons collected by the objective lens 452 and output image data; and the photoelectric signal processing module is configured to process the image data output by the camera to obtain an electrical signal representing the qubit. The camera and the photoelectric signal processing module can be two hardware devices connected to each other, or can be integrated on one hardware device, which is not limited in the present application.

[0228] The bit quantization unit 454 is configured to determine the quantum computing result of the first information and the second information according to the electrical signal.

[0229] It is worth noting that if the interatomic interaction representing a qubit is less than a set threshold, it indicates that the qubit logic gate is closed; if the interatomic interaction representing a qubit is greater than a set threshold, it indicates that the qubit logic gate is open. It is worth noting that if the interatomic interaction representing a qubit is equal to a set threshold, it indicates that the qubit logic gate is open or closed, and whether it is open or closed can be determined according to the needs of quantum computing, which is not limited in the present application.

[0230] In the embodiments of the present application, the use of a multi-component atomic system, combined with a specific interatomic spacing relationship in the atomic array, is beneficial to eliminate the next nearest neighbor interaction force in the atomic array, and only the nearest neighbor interaction force is retained. Further, the global Rydberg light (referred to as global light) is used to irradiate the atomic array, so that the information corresponding to the data bit corresponding to the target first atom is transmitted to a group of second atoms representing auxiliary bits, thereby realizing a low crosstalk data transmission process in the atomic array, greatly reducing the sensitivity to the position of the atom and the thermal motion of the atom, improving the information transmission fidelity and parallelism, thereby reducing the delay of quantum computing.

[0231] For the embodiments shown in FIGS. 6A to 13, the optical path used by the quantum computing system provided in the embodiments of the present application is exemplarily described below in combination with FIG. 14. FIG. 14 is a schematic diagram of the optical path of the quantum computing system provided in the present application. The required light beams in the atomic cavity 420 include atomic cooling light, global manipulation light, global Rydberg light, and atomic imaging light.

[0232] Among them, the atomic cooling light and the global manipulation light are used to rearrange the atoms, so that the arrangement relationship of each atom in the atomic array corresponds to the first information, such as ① to ④ in FIG. 14. It is worth noting that the various light beams in FIG. 14 can be adjusted by a dichroic mirror or other optical devices, which are not limited in the present application.

[0233] ①, generate a two-dimensional optical tweezers array (i.e. auxiliary bit optical tweezers array and rearrangement light) for trapping auxiliary bits through a spatial light modulator (SLM) or an acousto-optic deflector (AOD), and the spacing is (dx, dy).

[0234] ②, generate a two-dimensional optical tweezers array (i.e. data bit optical tweezers array and rearrangement light) for trapping data bits through a spatial light modulator (SLM) or an acousto-optic deflector (AOD), and the spacing is (dx, dy).

[0235] The array of data bits and the array of auxiliary bits form a multi-layer structure in the atomic cavity 420, with a spacing of dz on the z-axis, and dx = dy and dz satisfy dx / dz = tan54.7° = tanθ0.

[0236] According to the requirements of quantum computing, the quantum computing system can generate a light beam for manipulating the auxiliary bits (such as ③ auxiliary bit addressing manipulation light), and a light beam for manipulating the data bits (such as ④ data bit addressing manipulation light).

[0237] When data transfer between different components is performed, the data bits and the auxiliary bits are irradiated by the global Rydberg light at the same time, a directional interaction force between different components of atoms is generated, so that the information of the data bits can be transferred to the auxiliary bits, or the information of the auxiliary bits can be transferred to the data bits. The embodiment of the present application takes the information transfer of the data bits to the auxiliary bits as an example for description.

[0238] As shown in ⑤ in FIG. 14, after the auxiliary bits are irradiated by the atomic imaging light, the scattered photons of the auxiliary atom are collected by the objective lens and imaged on the camera to read out the result.

[0239] As shown in ⑥ in FIG. 14, after the data bits are irradiated by the atomic imaging light, the scattered photons of the data atom are collected by the objective lens and imaged on the camera to read out the result.

[0240] For the quantum computing system provided in the above embodiment and the different light beams shown in FIG. 14, two feasible specific embodiments are provided below to exemplarily describe the quantum computing system and the method provided in the present application.

[0241] In the first feasible specific embodiment, the ensemble auxiliary bits are used in the quantum computing system to improve the detection speed. As shown in FIG. 15, FIG. 15 is a flowchart of the fast detection using the ensemble auxiliary bits provided in the present application. The specific process of the detection includes the following (1) to (4).

[0242] (1) Array preparation: The atomic array corresponding to the quantum bits is prepared. The atomic array corresponding to the data bits of a single atom can be prepared by rearrangement light. The auxiliary bits of the ensemble (a plurality of second atoms) are not sensitive to the number of atoms, and can be directly prepared by random loading. In the actual experiment, the time consumption of array preparation is about 100 milliseconds (ms).

[0243] (2) Quantum computing: The data bits are used for computing, and the data bits are operated by using the same-component Rydberg light and the single-bit manipulation light (such as data bit state manipulation light), such as the interaction between a atom and b atom, and the interaction between c atom and d atom. Since the data bits and the auxiliary bits can be independently manipulated, the auxiliary bits can be cooled by the auxiliary bit cold light and prepared to a suitable quantum state. In the actual experiment, the time consumption of quantum computing is about 1 ms.

[0244] (3) Information transfer: using global off-resonant Rydberg interaction to generate a pair of strongly directional interactions. Through a specific gate operation, information is transferred from data bits to ancilla bits in parallel without crosstalk to other bits. The specific gate operation can be achieved by determining the physical distance between the first atom and the second atom in the atomic array, and then illuminating the atomic array with global Rydberg light. In actual experiments, the time consumption of information transfer is about 1 microsecond (μs)

[0245] (4) State detection: using ancilla bit state detection light (such as atomic imaging light in FIG. 14) to detect the ancilla bits. Since the number of atoms corresponding to the ancilla bit system of one data bit pair is large (about 100), the detection speed can be greatly improved. At the same time, there is no need to compensate for the small number of atoms lost in the detection of the ancilla bit system. In actual experiments, the time consumption of state detection is about 10 μs.

[0246] In the detection process of the ancilla bit, the quantum computing system can also rearrange the data bits or illuminate other light beams, so that the quantum computing system can start other computing processes, eliminate the limitation of quantum state reading, and greatly improve the computing efficiency of the quantum computing system.

[0247] In the prior art, the prior art scheme does not consider the information transfer scheme of the combination of atomic spacing and strong directional atomic interaction force, which makes the prior art scheme need to use addressing light to reduce the crosstalk to the atoms not participating in the operation. Since the beam waist of the addressing light is small, the effective light intensity experienced by the atom is highly sensitive to the position of the atom and the thermal motion of the atom. At the same time, since the multi-bit gate operation needs to use addressing light to illuminate multiple atoms at the same time, the sensitivity is further improved, which limits the fidelity of the multi-bit gate. In addition, since the general Rydberg interaction force is not directional, when a two-bit gate operation is performed on a pair of atoms, crosstalk will be generated to the neighboring atoms within the blocking radius, which limits the parallelism of the system.

[0248] Compared with the prior art, in the technical scheme provided in the embodiments of the present application, due to the strong directionality of the interaction force between atoms of different components, one-to-one interaction can be generated between data bits and auxiliary bits. Therefore, the information can be transmitted from the data bits to the auxiliary bits in parallel using global Rydberg light without causing crosstalk to other bits of the atomic array in the quantum computing system. Moreover, since global Rydberg light is used instead of addressing light, the sensitivity to the position of the atom and the thermal motion of the atom can be greatly reduced, and the information transmission fidelity is improved. In addition, since the number of atoms corresponding to the ensemble auxiliary bits is large, a small number of lost atoms in detection do not need to be reloaded every time the calculation is performed, and will not affect the detection. Furthermore, the data bits can skip the atomic array preparation and directly start a new calculation. Since the array preparation is the most time-consuming step in the entire experiment, the present scheme can greatly improve the calculation frequency by several orders of magnitude.

[0249] In a second possible embodiment, the multi-layer structure between the auxiliary bits and the data bits in the quantum computing system is used to cooperate with the atomic movement to perform parallel non-local gate operations. In combination with the foregoing content shown in FIG. 5, the optical tweezer unit 430 is further configured to move the optical tweezers in which a group of second atoms are captured according to the third information to obtain a target atomic array. The target atomic array includes a group of second atoms representing the auxiliary bits and a group of first atoms representing the migration target of the data bits paired with the auxiliary bits. One or more target second atoms in the group of second atoms are located in different layers from the migration target first atom, and the axis formed by the migration target first atom and the one target second atom is perpendicular to the layer containing the group of target second atoms, and the ratio between the first distance and the second distance is a reference value. The first distance is the transverse distance or the longitudinal distance between the one target second atom and the adjacent target second atom of the one target second atom, and the second distance is the distance between the one target second atom and the migration target first atom. The positional relationship between the migration target first atom and the one target second atom can be referred to the foregoing description of FIG. 6A, and will not be described here. The quantum bit measurement unit 450 is further configured to collect the scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by the probe light beam, and determine the quantum computing result of the third information and the second information according to the scattered photons.

[0250] The non-local gate operation will be described below with reference to FIG. 16. FIG. 16 is a flowchart of the non-local gate operation using single-atom auxiliary bits provided in the present application. The specific process of the non-local gate operation includes the following (1) to (4).

[0251] (1) Array preparation: A single-atom bit array, i.e., an atomic array corresponding to the first atom, is prepared by rearrangement, and a light tweezer with a suitable wavelength (magic wavelength) is selected so that the light tweezer of the two different bits reduces the influence on the other bit. In the actual experimental process, the time consumption of array preparation is about 100 ms.

[0252] (2) Information transfer: A one-to-one interaction with strong directionality is generated using global Rydberg light. Through specific gate operations, information is transferred from the data bit to the auxiliary bit in parallel without causing crosstalk to other bits. For example, the quantum bit represented by the t atom corresponding to the data bit is transferred to the m atom corresponding to the auxiliary bit. In the actual experimental process, the time consumption of information transfer is about 1 μs.

[0253] (3) Atomic movement: The second atom corresponding to the auxiliary bit is moved to the first atom, i.e., the e atom, which is the target first atom for migration, by using the light tweezer.

[0254] For example, in combination with (3) in FIG. 16, the axis connected between the e atom and the m atom is perpendicular to the layer containing multiple target second atoms, and the ratio between the first distance and the second distance is a reference value. The first distance is the lateral distance or the longitudinal distance between one target second atom (m atom) and the adjacent target second atom (e.g., the second atoms on both sides of the m atom in (3) of FIG. 16) of the target second atom (m atom), and the second distance is the distance between the target second atom (m atom) and the target first atom for migration (e atom). The description of the reference value and the related distance can refer to the content of the aforementioned FIG. 6A, which is not repeated here. In the actual experimental process, the time consumption of atomic movement corresponding to the auxiliary bit is about 1 ms.

[0255] (4) Non-local gate: A one-to-one interaction with strong directionality is generated using global Rydberg light, and a non-local gate operation with a certain parallelism can be performed based thereon. In the actual experimental process, the time consumption of the non-local gate is about 1 μs.

[0256] In the embodiments of the present application, after the information is transferred from the data bits to the auxiliary bits by using the parallel low crosstalk Rydberg operation, the auxiliary bits are moved to another region of the array, and then the parallel low crosstalk gate operation is performed again, so that the non-local gate operation is performed on the data bits in the two regions of the array. As can be known from the content provided in FIG. 16, by using the multi-layer arranged atomic structure and by moving the auxiliary bits, the parallel non-local gate operation with low crosstalk can be performed, which can be applied to quantum error correction codes, and by the non-local gate operation, the number of physical bits required per logical bit is reduced. Moreover, compared with the problem of long time consumption caused by moving all the data bits in the non-local gate operation in the prior art, in the quantum computing system provided in the embodiments of the present application, the optical tweezers only need to move a small number of auxiliary bits, thereby solving the problem that in the prior art, in order to reduce the moving and operation crosstalk, the spatial density of the data bits needs to be greatly reduced, which affects the total number of data bits, and the parallelism of the quantum computing system is improved.

[0257] Further, as can be known from FIGS. 15, 16 and the experimental data above, the preparation process of the atomic array consumes the longest time, and in the prior art, multiple preparations are required to realize quantum computing and state detection, while the quantum computing system and method provided in the embodiments of the present application only need to be prepared once, which greatly reduces the time required for quantum computing and improves the efficiency of quantum computing.

[0258] FIGS. 5 to 16 above are all described by taking the two-layer atomic array formed by the data bits and the auxiliary bits as an example, but the atomic array can also be designed as a more-layer structure or more types of atoms, which is not limited in the present application.

[0259] In some optional implementations, parallel low crosstalk information transfer is realized between the layers of the atomic array. The difficulty of using more components mainly lies in that different components need to use different laser cooling and manipulation. Too many lasers will bring difficulty to system design. Assuming that a two-component system is still used, the difficulty of extending to a multi-layer structure lies in how to image and rearrange the same component atoms in different layers. Since single atom imaging needs to use a large-aperture objective lens, the depth of field is only a few microns, so when imaging the same component atoms in different layers, the optical path needs to be dynamically adjusted (such as using an electrically controlled liquid crystal lens) to focus the fluorescence of the atoms in different layers onto the camera. In terms of rearrangement, the use of auxiliary bits can to some extent avoid the need for auxiliary bit rearrangement. As shown in FIG. 17, FIG. 17 is a loading schematic diagram of an atomic array including multi-layer auxiliary bits provided in the present application. In FIG. 17, the t atoms corresponding to the single-atom auxiliary bits correspond to: first layer ensemble auxiliary bits and second layer ensemble auxiliary bits. The information corresponding to the t atoms can be transferred to the first layer ensemble auxiliary bits or the second layer ensemble auxiliary bits according to user demand, and when the auxiliary bits are detected, the two layers of auxiliary bits can be weighted, so as to improve the detection efficiency of the second atoms corresponding to the auxiliary bits and improve the fidelity of the quantum computing system.

[0260] In summary, the application uses a multi-component atomic quantum computing system, by selecting appropriate magnetic quantum numbers and reasonable atomic array loading methods, to achieve strong directional interatomic interaction forces between different groups of atoms and specific interatomic spacing relationships, eliminate next nearest neighbor interaction forces, and only retain nearest neighbor interaction forces. Moreover, the application achieves parallel low crosstalk data transfer using global Rydberg light in the quantum computing system, greatly reduces the sensitivity to atomic positions and atomic thermal motion, and improves information transmission fidelity and parallelism.

[0261] In addition, by selecting appropriate orbital quantum numbers, the application achieves atomic interaction forces with strong directionality and adjustable strength, and the strength of the atomic interaction force changes by orders of magnitude with the angle, so that the magnetic quantum number of the atom can be quickly adjusted in the quantum computing or simulation process by changing the polarization and frequency of the light beam (the first polarized light beam and the second polarized light beam), to control the interatomic interaction force, and to improve the speed and efficiency of quantum computing.

[0262] The method steps in the embodiments of the application can also be implemented by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a terminal device. Of course, the processor and the storage medium can also exist as discrete components in electronic devices and multimedia devices.

[0263] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, a network device, a user equipment or other programmable apparatus. The computer programs or instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, for example, a floppy disk, a hard disk, a magnetic tape; or an optical medium, for example, a digital video disc (digital video disc, DVD); or a semiconductor medium, for example, a solid state disk (solid state drive, SSD).

[0264] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A quantum computing system, comprising: The application relates to a quantum computing system. The system comprises: an atom source configured to provide atoms of multiple types; an atom cavity connected to the atom source and configured to store the atoms provided by the atom source, wherein the atoms provided by the atom source include a plurality of first atoms representing data bits and a plurality of second atoms representing auxiliary bits, the auxiliary bits being used to temporarily store information corresponding to the data bits; a light tweezer unit configured to generate a plurality of light tweezers in the atom cavity and arrange the light tweezers that have captured the atoms in the atom cavity according to first information to obtain an atom array. The atom array includes a group of second atoms representing auxiliary bits and target first atoms corresponding to the data bits paired with the auxiliary bits, the group of second atoms includes one or more target second atoms, the target first atoms are located in a different layer from the group of second atoms, and an axis formed by the target first atoms and the group of target second atoms is perpendicular to the layer containing the group of target second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the group of target second atoms and another group of target second atoms adjacent to the group of target second atoms, and the second distance is a distance between the group of target second atoms and the target first atoms. A global light emitter is configured to generate global light according to second information, the global light being used to irradiate the atom array so that information corresponding to the data bits corresponding to the target first atoms is transmitted to the auxiliary bits represented by the group of second atoms.

2. The quantum computing system of claim 1, wherein, A qubit measurement unit is configured to collect scattered photons generated by the group of second atoms corresponding to the auxiliary bits after irradiation by a probe light beam and determine a quantum computing result of the first information and the second information according to the scattered photons. The reference value is K, K=tan theta, and theta is greater than or equal to 49.7 degrees and less than or equal to 59.7 degrees.

3. The quantum computing system of claim 1 or 2, wherein In the atom array, an interatomic interaction force between the target first atoms and the group of target second atoms is greater than an interatomic interaction force between the target first atoms and other groups of second atoms, the other groups of second atoms being second atoms in the atom array other than the group of second atoms.

4. The quantum computing system of any one of claims 1-3, wherein The light tweezer unit is further configured to move the light tweezers that have captured the group of second atoms according to third information to obtain a target atom array. The target atomic array includes a group of second atoms representing auxiliary bits and a target first atom of a data bit paired with the auxiliary bit, one or more target second atoms in the group of second atoms are located in different layers from the target first atom, and an axis formed by the target first atom and the group of second atoms is perpendicular to a layer containing the group of second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the group of second atoms and another group of second atoms adjacent to the group of second atoms, and the second distance is a distance between the target second atom and the target first atom. The quantum bit measurement unit is further configured to collect scattered photons generated by the group of second atoms corresponding to the auxiliary bits after being irradiated by the probe light beam, and determine the quantum computing result of the third information and the second information according to the scattered photons.

5. The quantum computing system of any one of claims 1-4, wherein, The global light emitter includes: An excitation light source configured to provide an irradiation light beam; A light path modulation component connected to the excitation light source and configured to process a light parameter of the irradiation light beam according to the second information to obtain the global light, the light parameter including one or a combination of the following: light beam direction, polarization, and frequency.

6. The quantum computing system of claim 5, wherein, The light path modulation component includes: An acousto-optic modulator (AOM) and a beam splitter; Or an electro-optic modulator (EOM) and a polarization beam splitter (PBS); Or a digital micromirror device (DMD).

7. The quantum computing system of any one of claims 1-6, wherein, The multiple optical tweezers have different wavelengths, wherein optical tweezers in a first wavelength range are used to capture the first atoms, and optical tweezers in a second wavelength range are used to capture the second atoms.

8. A method of quantum computing, comprising: The quantum computing method is applied to the quantum computing system of any one of claims 1-7, and the method includes: An atomic source provides multiple types of atoms; An atomic cavity stores the atoms provided by the atomic source, and the atoms provided by the atomic source include multiple first atoms representing data bits and multiple second atoms representing auxiliary bits, the auxiliary bits being used to temporarily store information corresponding to the data bits; An optical tweezer unit generates multiple optical tweezers in the atomic cavity and arranges optical tweezers in which atoms in the atomic cavity are captured according to first information to obtain an atomic array; The atomic array includes a group of second atoms representing auxiliary bits and a target first atom corresponding to a data bit paired with the auxiliary bit, the group of second atoms includes one or more target second atoms, the target first atom and the group of second atoms are located in different layers, and an axis formed by the target first atom and the group of second atoms is perpendicular to a layer containing the group of second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the group of second atoms and another group of target second atoms adjacent to the group of second atoms, and the second distance is a distance between the group of target second atoms and the target first atom. The global light emitter generates global light according to the second information, the global light is used for irradiating the atomic array, and information corresponding to a data bit corresponding to the target first atom is transmitted to an auxiliary bit represented by the group of second atoms; The qubit measurement unit collects scattered photons generated by the group of second atoms corresponding to the auxiliary bit after irradiation by a probe light beam, and determines a quantum calculation result of the first information and the second information according to the scattered photons.

9. The method of claim 8, wherein, The reference value is K, K=tanθ, θ is greater than or equal to 49.7°, and θ is less than or equal to 59.7°.

10. The method according to claim 8 or 9, characterized in that, The method further comprises: The optical tweezer unit moves the optical tweezer in which the group of second atoms is captured according to third information to obtain a target atomic array; The target atomic array comprises a group of second atoms representing an auxiliary bit and a migration target first atom of a data bit paired with the auxiliary bit, one or more target second atoms in the group of second atoms are located in different layers from the migration target first atom, and an axis formed by the migration target first atom and the group of second atoms is perpendicular to a layer containing the group of second atoms, and a ratio between a first distance and a second distance is a reference value, the first distance is a transverse distance or a longitudinal distance between the group of second atoms and an adjacent group of second atoms of the group of second atoms, and the second distance is a distance between the group of second atoms and the migration target first atom. The qubit measurement unit collects scattered photons generated by the group of second atoms corresponding to the auxiliary bit after irradiation by a probe light beam, and determines a quantum calculation result of the third information and the second information according to the scattered photons.

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