An optical addressing system for two-dimensional single-atom arrays

Abstract

This utility model relates to the field of atomic manipulation technology in quantum information processing devices, and more particularly to an optical addressing system for a two-dimensional single-atom array, comprising a laser arranged sequentially according to the optical path direction, a pair of orthogonally arranged acousto-optic deflectors, a first lens, a second lens, and a third lens, wherein the acousto-optic deflectors include an acousto-optic deflector (AOD). y Acoustic-optical deflector (AOD) x The acousto-optic deflector (AOD) y Acoustic-optical deflector (AOD) x The input terminals are respectively connected to the output terminals of an arbitrary waveform generator. This invention, through the combination of an acousto-optic deflector and a lens group, enables precise and rapid addressing of two-dimensional single-atom arrays. This invention possesses high stability and scalability, and can be extended to address larger-sized two-dimensional single-atom arrays, making it suitable for future large-scale quantum computing and quantum simulation systems.

Description

Technical Field

[0001] This invention relates to the field of atomic manipulation technology for quantum information processing devices, and more particularly to an optical addressing system for two-dimensional single-atom arrays. Background Technology

[0002] Currently, there are three main technical routes in the field of quantum information processing: superconducting circuit systems (coherence time ~100 μs), trapped ion systems (coherence time ~10 s), and neutral atom systems (coherence time >1 s). Among them, the neutral atom system exhibits unique advantages: (1) environmental robustness, which can withstand magnetic field fluctuations of ±5 Gauss, far exceeding that of superconducting circuits (<0.1 Gauss tolerance); (2) scalability potential, that is, it naturally supports the integration of kilobit-level arrays, breaking through the spatial limitations of ion traps; (3) manipulation flexibility, that is, optical means can realize multi-degree-of-freedom control (spin / orbit / energy state). This system has become an ideal carrier for realizing large-scale quantum processors, especially with broad prospects in the fields of quantum simulation and precision measurement.

[0003] In recent years, researchers have successfully realized optical traps from one-dimensional to three-dimensional using methods such as multi-beam spatial interference, two-dimensional spatial diffraction, and incoherent beam arrays, and have studied efficient single-atom loading and fabrication. However, quantum computing and quantum information processing require independent quantum manipulation of each atom in the array, which necessitates the development of a matching single-atom addressing system.

[0004] To achieve spatially resolvable addressing, the distance between atoms in the array is typically controlled on the order of a few micrometers. A highly focused beam of light allows for precise positioning and manipulation of target atoms while avoiding interference with neighboring atoms. Furthermore, practical quantum logic operations require different quantum operations to be performed on qubits at different locations in a predetermined time sequence; therefore, the positioning beam needs to be able to switch rapidly and accurately between different array lattice points.

[0005] However, existing addressing systems often suffer from interference between addressing channels when performing parallel addressing manipulation of qubits, which seriously affects the fidelity of quantum gate manipulation. Moreover, as the number of qubits increases, the scalability of existing addressing systems is insufficient, making it difficult to meet the addressing requirements of large-scale neutral atom qubit arrays. Utility Model Content

[0006] To meet the addressing requirements of large-scale neutral atom qubit arrays, this invention provides an optical addressing system for two-dimensional single-atom arrays.

[0007] This utility model is achieved through the following technical solution: an optical addressing system for a two-dimensional single-atom array, comprising a laser arranged sequentially according to the optical path direction, a pair of orthogonally arranged acousto-optic deflectors, a first lens, a second lens, and a third lens, wherein the acousto-optic deflectors include an acousto-optic deflector (AOD). y Acoustic-optical deflector (AOD) x The acousto-optic deflector (AOD) y Acoustic-optical deflector (AOD) x The input terminals are respectively connected to the output terminals of an arbitrary waveform generator.

[0008] As a further improvement to the technical solution of this utility model, a cylindrical mirror is provided between the first lens and the second lens.

[0009] As a further improvement to the technical solution of this utility model, the focal length of the first lens is 150mm, the focal length of the second lens is 300mm, and the focal length of the third lens is 23mm.

[0010] As a further improvement to the technical solution of this utility model, the focal length of the cylindrical mirror is 1000mm.

[0011] As a further improvement to the technical solution of this utility model, the distance between the cylindrical mirror and the first lens is 130mm.

[0012] As a further improvement to the technical solution of this utility model, the light-incident surface and the light-exit surface of the first lens, the second lens and the third lens are all provided with a lens coating layer.

[0013] As a further improvement to the technical solution of this utility model, both the incident surface and the exit surface of the cylindrical mirror are provided with a lens coating layer.

[0014] The optical addressing system for two-dimensional single-atom arrays provided by this invention has the following advantages compared with the prior art:

[0015] This invention, through the combination of an acousto-optic deflector and a lens group, enables precise and rapid addressing of a 5×5 two-dimensional single-atom array with a grid spacing of 4.3 micrometers. An arbitrary waveform generator can rapidly switch the driving radio frequency of the acousto-optic deflector, achieving rapid positioning of the addressing light within the two-dimensional array. The response time is 6.3 microseconds, and the switching speed is 1.9 microseconds. These times are far less than the atomic lifetime in the array, allowing for rapid switching of the addressing light between different grid points, meeting the demands of rapid operation in quantum computing. This invention exhibits high stability and scalability, and can be extended to address larger-sized two-dimensional single-atom arrays, making it suitable for future large-scale quantum computing and quantum simulation systems. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the optical path of a two-dimensional single-atom array addressing system provided in an embodiment of the present invention, showing the optical path arrangement of the two-dimensional acousto-optic deflector, lens group and cylindrical mirror.

[0019] Figure 2 This is a graph showing the relationship between the addressing light displacement at the focal point of the first lens and the radio frequency of the acousto-optic deflector in two-dimensional space in an embodiment of this utility model.

[0020] Figure 3 The image shows the light spot at 25 atomic positions in the two-dimensional single-atom array in this embodiment of the invention. Figure (a) is a two-dimensional image, and Figure (b) is a three-dimensional image.

[0021] Figure 4 This is a response time diagram of the acousto-optic converter to the optical switch in an embodiment of this utility model.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1-Laser; 2-Acousto-optic deflector (AOD) y 3-Acousto-optic deflector (AOD) x ; 4-First lens; 5-Cylindrical mirror; 6-Second lens; 7-Third lens; 8-Two-dimensional single-atom array; 9-Arbitrary waveform generator. Detailed Implementation

[0024] To better understand the above-mentioned objectives, features, and advantages of this utility model, the solution of this utility model will be further described below. It should be noted that, unless otherwise specified, the embodiments of this utility model and the features thereof can be combined with each other.

[0025] In the description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the present invention, and not all embodiments.

[0027] The specific embodiments of this utility model will be described in detail below.

[0028] like Figure 1 As shown, this utility model provides a specific embodiment of an optical addressing system for a two-dimensional single-atom array, including a laser 1 arranged sequentially according to the optical path direction, a pair of orthogonally arranged acousto-optic deflectors, a first lens 4, a second lens 6, and a third lens 7. The acousto-optic deflectors include an acousto-optic deflector (AOD). y 2 and AOD (Audio-Optical Deflector) x 3. The acousto-optic deflector (AOD) y 2. Acoustic-optical deflector (AOD) x The input terminals of 3 are connected to the output terminals of the arbitrary waveform generator 9.

[0029] The specific working principle of this utility model is as follows:

[0030] After passing through an acousto-optic deflector, the addressing light is focused onto a two-dimensional single-atom array 8 via a telescope system composed of lens groups. Then, an arbitrary waveform generator 9 controls the position of the addressing light in two-dimensional space by changing the driving radio frequency frequency of the acousto-optic deflector, ensuring precise focusing on the lattice point where the target atom is located. The addressing light interacts with the target atom, generating a light frequency shift, thereby distinguishing the target atom from other atoms in the array.

[0031] In some embodiments, the two-dimensional single-atom array 8 may be a two-dimensional single cesium atom array.

[0032] In this embodiment, when an addressing light with a power of 6mW, a wavelength of 910nm, and a waist size of 1.15mm is applied to a cesium atom, the cesium atom clock state (|F=4,m F =0> and |F=3,m F A 104 kHz optical frequency shift is generated between =0>), corresponding to an attractive potential well depth of 3.9 mK. At this time, the scattering rate of the atom to the addressing light is 321 photons per second, and one π pulse (corresponding to a clock state manipulation frequency of 10 kHz, with a π pulse width of 50 ms) scatters 0.02 photons.

[0033] like Figure 1 As shown, an acousto-optic deflector of model DTSXY-400-1064 is selected. The acousto-optic deflector includes orthogonally arranged acousto-optic deflectors (AODs). y 2 and AOD (Audio-Optical Deflector) x3. And the acousto-optic deflector AOD y 2 and AOD (Audio-Optical Deflector) x The diffraction directions of lasers 3 are perpendicular to each other, and the angle of their first-order diffracted light varies with the driving radio frequency. The addressing source (laser 1) selects a laser with a wavelength of 910 nm and a waist spot radius of 2.5 mm, which enters the acousto-optic deflector. Its first-order diffracted light passes through the first lens 4. The focal point of the first lens 4 is located at the acousto-optic deflector (AOD). y 2. Center of the acousto-optic deflector (AOD) y The first-order diffracted light from point 2 is parallel to the optical axis after passing through the first lens 4. The focal length of the first lens 4 is... f 1 =150mm, and the addressing spot at the rear focal point of the first lens 4 is 15mm. This spot is then projected onto the two-dimensional atomic array 8 by a telescope system formed by the confocal placement of the second lens 6 and the third lens 7. Since the focal lengths of the second lens 6 and the third lens 7 are respectively... f 2 =300mm and f 3 =23mm, and the addressing spot size can be 1.15mm at the back focal plane of the third lens 7.

[0034] For the acousto-optic deflector AOD in the x-direction x 3. Due to its spatial location relative to the acousto-optic deflector AOD y If the optical path difference is 24mm, the first-order diffracted light will not be parallel to the optical axis after passing through the first lens 4. Consequently, the light projected onto the two-dimensional atomic array 8 after passing through the second lens 6 and the third lens 7 will also not be parallel to the optical axis, thus affecting the quality and addressing accuracy of the addressing spot. Therefore, preferably, a cylindrical mirror 5 is added between the first lens 4 and the second lens 6 to compensate for the optical path difference in the x-direction, without affecting the light in the y-direction. The focal length of the cylindrical mirror 5 is... f =1000mm, the distance between cylindrical mirror 5 and first lens 4 is calculated and designed to be 130mm. After the addressing light passes through the telescope system composed of the acousto-optic deflector and lens group, the addressing light is focused onto the two-dimensional single-atom array 8. Then, the AOD of the acousto-optic deflector is changed by the arbitrary waveform generator 9. y 2 and AOD (Audio-Optical Deflector) x The driving radio frequency of 3 controls the position of the addressing light in two-dimensional space.

[0035] Preferably, the light-incident and light-exit surfaces of the first lens 4, the second lens 6, and the third lens 7 are all provided with lens coating layers. The lens coating layer on each lens is a 910nm high-transmission film.

[0036] Furthermore, both the incident and exit surfaces of the cylindrical mirror 5 are provided with lens coating layers. The lens coating layer of the cylindrical mirror 5 is a 910nm high-transmission film.

[0037] In use, initially, the addressing light is located at the center (3, 3) of the 5×5 two-dimensional single-atom array 8, with a distance of 4.3 mm between adjacent atoms. By changing the radio frequency of the acousto-optic deflector, the addressing light can move ±8.6 mm in the x and y directions, covering the entire 5×5 array.

[0038] Specifically, in this embodiment, when applied to the acousto-optic deflector AOD... y 2 and AOD (Audio-Optical Deflector) x When the frequency of 3 is scanned at a fixed frequency of 200kHz up, down, left and right, the position and size of the light spot are recorded at the focal point behind the first lens 4 each time. Figure 2 To determine the relationship between the addressing light displacement at the focal point of the first lens 4 and the radio frequency of the acousto-optic deflector in two-dimensional space, the results show that the light spot displacement changes linearly with frequency: 210.73 mm / MHz in the horizontal direction and 208.32 mm / MHz in the vertical direction. Therefore, after passing through the telescope system composed of the lens group, i.e., in the two-dimensional dipole well, the relationship between the addressing light displacement and frequency in the horizontal and vertical directions is 16.21 mm / MHz and 16.02 mm / MHz, respectively. In the two-dimensional dipole well, the distance between adjacent wells is 4.3 mm, corresponding to frequencies that the acousto-optic deflector needs to change in the horizontal and vertical directions of 265.27 kHz and 268.41 kHz, respectively. The accuracy of the acousto-optic deflector can reach 0.23 Hz, meeting the addressing requirements.

[0039] Specifically, in this embodiment, the light spots at 25 atomic positions in a two-dimensional atomic array were measured. For example... Figure 3 As shown in (a), Figure 3 (b) is a three-dimensional image. In this embodiment, Gaussian fitting is performed on the waist of each light spot. Finally, the waist of the upper left light spot is the smallest and the waist of the lower right light spot is the largest. After being reduced by a factor of 13 by the telescope system composed of lens groups, the waist size of the addressing light is between 1 mm and 1.2 mm, which meets the addressing requirements.

[0040] Specifically, in this embodiment, the response time of the acousto-optic converter is tested, such as... Figure 4 The results show a delay time of 6.3 ms and a switching speed of 1.9 ms, which meets the requirements for fast addressing. The size of the waist spot of the addressing light was measured using Gaussian fitting to ensure it is between 1 mm and 1.2 mm, meeting the addressing accuracy requirements.

[0041] When the addressing system described in this embodiment is used for addressing a larger two-dimensional single-atom array 8, precise control of the larger array can be achieved simply by adjusting the parameters of the lens group and the acousto-optic converter.

[0042] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and all should be covered by the protection scope of the claims.

Claims

1. An optical addressing system for a two-dimensional single-atom array, characterized in that, The system includes a laser (1) arranged sequentially according to the optical path direction, a pair of orthogonally arranged acousto-optic deflectors, a first lens (4), a second lens (6), and a third lens (7), wherein the acousto-optic deflectors include an acousto-optic deflector (AOD). y (2) Acousto-optic deflector (AOD) x (3) The acousto-optic deflector AOD y (2) Acousto-optic deflector (AOD) x (3) The input terminals are connected to the output terminals of the arbitrary waveform generator (9).

2. The optical addressing system for a two-dimensional single-atom array according to claim 1, characterized in that, A cylindrical mirror (5) is provided between the first lens (4) and the second lens (6).

3. The optical addressing system for a two-dimensional single-atom array according to claim 1, characterized in that, The focal length of the first lens (4) is 150mm, the focal length of the second lens (6) is 300mm, and the focal length of the third lens (7) is 23mm.

4. The optical addressing system for a two-dimensional single-atom array according to claim 2, characterized in that, The focal length of the cylindrical mirror (5) is 1000mm.

5. An optical addressing system for a two-dimensional single-atom array according to claim 2 or 4, characterized in that, The distance between the cylindrical mirror (5) and the first lens (4) is 130mm.

6. An optical addressing system for a two-dimensional single-atom array according to claim 1 or 3, characterized in that, The light-incident and light-outcident surfaces of the first lens (4), the second lens (6), and the third lens (7) are all provided with lens coating layers.

7. An optical addressing system for a two-dimensional single-atom array according to claim 2 or 4, characterized in that, Both the incident and exit surfaces of the cylindrical mirror (5) are provided with lens coating layers.

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