A magneto-optical trap device, an atomic device, and a quantum computer

Abstract

This application provides a magneto-optical trap device, an atomic device, and a quantum computer, relating to the field of magneto-optical trap technology, to address the problems of large size, optical path obstruction, and residual magnetic fields caused by anti-Helmholtz coils. The magneto-optical trap device includes a vacuum cavity and an optical system; the vacuum cavity is used to contain target atoms. The optical system generates three pairs of cooling beams directed in three orthogonal directions and three pairs of magnetic field beams propagating in the same direction as the three pairs of cooling beams. The cooling beams are laser beams used for Doppler cooling of the target atoms; the three pairs of cooling beams intersect at the trap center position in the vacuum cavity to form an optical cluster at the trap center position; the magnetic field beams are laser beams used to generate an equivalent magnetic field for the target atoms, and the three pairs of magnetic field beams intersect at the trap center position to cooperate with the three pairs of cooling beams to trap the target atoms in the optical cluster. The above-described magneto-optical trap device can be applied to atomic devices.

Description

Technical Field

[0001] This application relates to the field of magneto-optical trap technology, and more particularly to a magneto-optical trap device, an atomic device, and a quantum computer. Background Technology

[0002] Magneto-optical trap (MOT) is a technique that uses Doppler cooling and the Zeeman effect to cool and trap neutral atoms. It is commonly used to cool and trap alkali metal atoms.

[0003] A magneto-optical trap device provided in related technologies includes a vacuum cavity, an optical system, and a pair of anti-Helmholtz coils. The vacuum cavity is used to contain the target atom acted upon by the magneto-optical trap device. The optical system, disposed outside the vacuum cavity, generates six beams of cooling light that illuminate the vacuum cavity. These six beams of cooling light can form optical molasses at their intersections, which can decelerate and cool the target atom within the vacuum cavity. The pair of anti-Helmholtz coils, disposed outside the vacuum cavity, generates a gradient magnetic field. This gradient magnetic field, in conjunction with the six beams of cooling light having specific polarization states, forms a potential trap to confine the target atom within the optical molasses for continuous cooling.

[0004] However, in the aforementioned magneto-optical trap devices provided by related technologies, the heat dissipation of the anti-Helmholtz coil and the required magnetic field strength are mutually constrained, resulting in a large coil volume and thus a large overall device structure, making integration and miniaturization difficult. Furthermore, the anti-Helmholtz coil and its mounting structure can obstruct the optical path of the cooling light, thus limiting the direction and position of the cooling light illumination, increasing the design and fabrication difficulty of the magneto-optical trap device. Moreover, the anti-Helmholtz coil also suffers from the problem of residual magnetic fields. Summary of the Invention

[0005] This application provides a magneto-optical trap device, an atomic device, and a quantum computer to improve the problems of large size, obstruction of the optical path, and residual magnetic field caused by anti-Helmholtz coils.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] In a first aspect, a magneto-optical trap device is provided, which includes a vacuum cavity and an optical system; wherein the vacuum cavity is used to contain target atoms.

[0008] The optical system is used to generate three pairs of cooling beams that are directed in three-dimensional orthogonal directions. The cooling beams are laser beams used to perform Doppler cooling on the target atoms. The three pairs of cooling beams intersect at the center of the trap to form an optical cluster at the center of the trap. The center of the trap is located in a vacuum cavity.

[0009] The optical system is also used to generate three pairs of magnetic field lights that travel in the same direction as the three pairs of cooling lights, and the three pairs of magnetic field lights cross at the center of the trap; the magnetic field lights are laser beams used to generate an equivalent magnetic field on the target atoms, and the three pairs of magnetic field lights are used in conjunction with the three pairs of cooling lights to trap the target atoms in optical aggregates.

[0010] In the magneto-optical trap device provided in this application, a specially designed magnetic field light can generate an equivalent magnetic field on the target atoms, achieving the same effect as an anti-Helmholtz coil, thus enabling the design of an all-optical magneto-optical trap. This design avoids the problems of large size and residual magnetic fields associated with using anti-Helmholtz coils, significantly simplifying the device and facilitating miniaturization and integration. Furthermore, the magnetic field light and cooling light propagate in the same direction, without occupying an additional optical path, avoiding the problem of anti-Helmholtz coils blocking the cooling light's path. This allows for greater freedom in the direction and position of the cooling light's illumination, reducing the design and fabrication difficulty of the magneto-optical trap device.

[0011] In some possible implementations, each pair of magnetic field beams includes a first beam and a second beam projected in the same orthogonal direction. Both beams are circularly polarized with the same direction of rotation, and their intensity gradually decreases as they approach the center of the trap along the transmission direction. This design allows for the generation of a gradient magnetic field with an equivalent magnetic field strength variation by controlling the change in light intensity, achieving the same effect as an anti-Helmholtz coil.

[0012] In some possible implementations, both the first and second beams are Gaussian beams. This design reduces the difficulty of generating magnetic field light while still achieving the gradient magnetic field effect.

[0013] In some possible implementations, the waist positions of both the first and second beams are located on the incident side relative to the center of the trap, and the spacing between the waist positions of the first and second beams in the orthogonal direction is 1 to 3 times the Rayleigh length. This design ensures that the equivalent magnetic field strength is zero at the center of the trap (magnetic field center) and that the gradient variation is uniform near the center of the trap (magnetic field center).

[0014] In some possible implementations, of the three pairs of magnetic field lights, two pairs are circularly polarized light with a first rotation direction, and the other pair is circularly polarized light with a second rotation direction; wherein the first rotation direction is either left-handed or right-handed, and the second rotation direction is either left-handed or right-handed. This design allows the equivalent magnetic field generated by the three pairs of magnetic field lights to be the same source-free field as the magnetic field generated by a pair of anti-Helmholtz coils.

[0015] In some possible implementations, the wavelengths of the cooling light and the magnetic field light propagating in the same direction are different, and they are circularly polarized light with opposite rotation directions. With this design, the cooling light and the magnetic field light work together to cause the target atom to be scattered by the cooling light as it moves away from the center of the trap. This scattering force is directed towards the center of the trap, and the scattering force increases the further away from the center of the trap, thereby creating a potential trap for the target atom.

[0016] In some possible implementations, the optical system includes two first subsystems located on either side of the center of the trap in the same orthogonal direction. The first subsystems are used to generate cooling light and magnetic field light that propagate in the same direction toward the center of the trap along the orthogonal direction.

[0017] Alternatively, the optical system includes a first subsystem and a second subsystem located on either side of the center of the trap in the same orthogonal direction. The first subsystem is used to generate cooling light and magnetic field light that are transmitted in the same direction toward the center of the trap along the orthogonal direction. The second subsystem is used to reflect the cooling light and magnetic field light. The reflected cooling light and magnetic field light are transmitted in the same direction toward the center of the trap along the same orthogonal direction.

[0018] The magneto-optical trap device provided in this application can use different optical systems to generate counter-current cooling light and counter-current magnetic field light, making it flexible and diverse in structure and suitable for different application scenarios.

[0019] In an implementation of an optical system that includes a second subsystem, the structure can be simplified and costs reduced by reflecting cooling light and magnetic field light.

[0020] In some possible implementations, the first subsystem includes a cooling light component, a magnetic field light component, and a first beam splitting and combining device; the cooling light component includes a first light source and a first polarization conversion device, the first light source being used to generate cooling light in a first polarization state, and the first polarization conversion device being used to convert the cooling light into circularly polarized light in a first rotation direction.

[0021] The magnetic field light assembly includes a second light source, a first converging lens, and a second polarization conversion device. The second light source is used to generate magnetic field light with a second polarization state, the first converging lens is used to converge the magnetic field light, and the second polarization conversion device is used to convert the magnetic field light into circularly polarized light with a second rotation direction.

[0022] The first beam splitting and combining device is used to combine the cooling light generated by the cooling light component and the magnetic field light generated by the magnetic field light component, and then transmit the combined cooling light and magnetic field light towards the center of the trap along their orthogonal directions.

[0023] The first subsystem using the above design can generate cooling light and magnetic field light with different rotation directions, and the cooling light and magnetic field light are transmitted in the same direction, which helps to ensure the working performance of the magneto-optical trap device.

[0024] In some possible implementations, the first polarization state and the second polarization state are orthogonal linear polarizations, the first polarization conversion device and the second polarization conversion device are the same quarter-wave plate, and the quarter-wave plate is located on the exit side of the beam combiner. This design, through the sharing of structures, helps to simplify the structure and reduce costs.

[0025] In some possible implementations, the first polarization state is one of P-polarization and S-polarization, the second polarization state is the other of P-polarization and S-polarization, and the first beam splitter / combiner is a polarization beam combiner. This design is advantageous for the generation and processing of cooling light and magnetic field light.

[0026] In some possible implementations, the second subsystem includes a second beam splitter / combiner, a first reflector, a second reflector, and a second converging lens; the second beam splitter / combiner is used to split the cooling light and magnetic field light traveling in the same direction, and guide the cooling light to the first reflector and the magnetic field light to the second reflector; the first reflector is used to reflect the cooling light and the second reflector is used to reflect the magnetic field light.

[0027] The second beam splitting and combining device is also used to combine the cooling light reflected by the first reflecting device and the magnetic field light reflected by the second reflecting device, and to transmit the combined cooling light and magnetic field light towards the center of the trap along the orthogonal direction; the second converging lens is used to converge the magnetic field light.

[0028] This design allows for the reflection of cooling light and magnetic field light through a second subsystem while maintaining optical performance.

[0029] In some possible implementations, the first subsystem further includes a beam splitter for splitting the magnetic field light into multiple parallel sub-magnetic field lights. In the magneto-optical trap device provided in this application, the multiple sub-magnetic field lights generated by the optical system intersect at different positions in three-dimensional space, thereby forming multiple micro-gradient magnetic fields located at different positions in three-dimensional space within the optical aggregate. These micro-magnetic field lights can then be combined with cooling light to form multiple micro-magnetic field traps, which are arrayed in a first direction, a second direction, and a third direction. This design can adapt to different application scenarios, and the spacing between the aforementioned micro-magnetic field traps can be reduced to less than approximately 100 μm, which is difficult to achieve for magneto-optical traps using anti-Helmholtz coils.

[0030] In some possible implementations, the beam splitter is a spatial light modulator. This design not only achieves beam splitting but also allows for adjustment of the splitting pattern, offering greater flexibility.

[0031] In some possible implementations, the target atom is a rubidium atom, and the wavelength of the magnetic field light is 790 nm; or, the target atom is a potassium atom, and the wavelength of the magnetic field light is 769 nm; or, the target atom is a lithium atom, and the wavelength of the magnetic field light is 670 nm; or, the target atom is a cesium atom, and the wavelength of the magnetic field light is 878.5 nm. The magneto-optical trap device provided in this application can achieve the cooling and trapping of alkali metal atoms such as rubidium, potassium, lithium, and cesium atoms.

[0032] In a second aspect, an atomic device is provided, comprising a magneto-optical trap device as described in any of the first aspects; and a processing device for processing target atoms cooled and trapped by the magneto-optical trap device.

[0033] Thirdly, a quantum computer is provided that includes a magneto-optical trap device as described in any of the first aspects.

[0034] The technical effects achievable by the atomic devices and quantum computers provided in this application are the same as those achievable by the magneto-optical trap device in the first aspect, and will not be repeated here. Attached Figure Description

[0035] Figure 1 A schematic diagram of the principle of a magneto-optical trap provided for related technologies;

[0036] Figure 2 A schematic diagram of a magneto-optical trap device provided for related technologies;

[0037] Figure 3 This is a schematic diagram of the structure of a magneto-optical trap device provided in an embodiment of this application;

[0038] Figure 4 This is a diagram showing the energy level splitting results of different alkali metal atoms under magnetic field light irradiation, provided in the embodiments of this application.

[0039] Figure 5 The magnetic field light provided in the embodiments of this application is used to target rubidium atoms. 87 The result of the equivalent magnetic field generated by Rb is shown in the figure.

[0040] Figure 6 A schematic diagram illustrating the principle of generating an equivalent magnetic field from three pairs of magnetic field lights, provided in an embodiment of this application.

[0041] Figure 7 A schematic diagram illustrating the principle of a pair of magnetic field lights generating an equivalent magnetic field, provided in an embodiment of this application.

[0042] Figure 8 A comparison diagram showing the equivalent magnetic fields generated by a pair of magnetic field lights with different waist spacings provided in the embodiments of this application;

[0043] Figure 9 A structural diagram of a first subsystem provided in an embodiment of this application;

[0044] Figure 10 This is a schematic diagram of another magneto-optical trap device provided in an embodiment of this application;

[0045] Figure 11 A structural diagram of a second subsystem provided in an embodiment of this application;

[0046] Figure 12 A structural diagram of another magnetic field optical component provided in this application embodiment;

[0047] Figure 13 A schematic diagram illustrating the generation of a miniature magneto-optical trap, provided for an embodiment of this application;

[0048] Figure 14 This is a schematic diagram of the structure of an atomic device provided in an embodiment of this application. Detailed Implementation

[0049] A magneto-optical trap (MOT) is a technique that uses Doppler cooling and the Zeeman effect to cool and trap neutral atoms, and is commonly used to cool and trap alkali metal atoms. To facilitate understanding of the technical solutions provided in the embodiments of this application, the working principle of the magneto-optical trap will be briefly explained below.

[0050] Doppler cooling is a technique that utilizes the Doppler effect and resonant absorption to drastically reduce atomic velocity, achieving extremely low temperatures. Its working principle is as follows: a laser with a frequency slightly lower than the atomic transition frequency (red detuning) is used as the cooling light. When an atom moves towards the cooling light, the laser frequency it experiences increases due to the Doppler effect, thus matching the atom's transition frequency and allowing the atom to absorb a photon. Once the atom absorbs the photon, it transitions from the ground state to an excited state, gaining the momentum of the photon, causing its velocity to decrease. Subsequently, the atom returns to the ground state through spontaneous emission, releasing a photon that scatters in random directions.

[0051] During the process of atoms continuously absorbing and releasing photons, they continuously absorb photons from the same direction and scatter them in random directions. Therefore, in general, atoms are only subject to the force generated by absorbing photons, which is called the scattering force. The direction of this scattering force is the same as the direction of transmission of the cooling light, that is, opposite to the direction of the atom's motion. This allows the atoms moving towards the cooling light to continuously decelerate, thus achieving the purpose of cooling the atoms.

[0052] In a magneto-optical trap, six red-detuned cooling beams are typically shone orthogonally in three dimensions and intersect at the same location, forming an optical molasses at that intersection. Within this optical molasses, the motion of atoms in three degrees of freedom can be decelerated simultaneously, so that atoms in this specific region will experience a scattering force that slows them down regardless of their direction of motion; thus, a molasses of atoms cooled by deceleration can be maintained.

[0053] The Zeeman effect refers to the phenomenon where the magneton energy levels of an atom split when the atom is placed in an external magnetic field. The magnitude of the splitting of the magneton energy levels, i.e., the Zeeman shift, is positively correlated with the magnetic field strength, and the direction of the splitting of the magneton energy levels, i.e., the direction of the Zeeman shift, is related to the direction of the magnetic field.

[0054] In a magneto-optical trap, a gradient magnetic field is typically employed, centered at the intersection of the cooling beams. This gradient magnetic field has zero strength at the center (the intersection of the cooling beams) and gradually increases in strength as it moves away from the center along three orthogonal directions. Furthermore, the gradient magnetic fields on either side of the center are symmetrical along the same orthogonal direction. Under the influence of this gradient magnetic field, the magneton energy levels of atoms at the center do not split, i.e., the Zeeman shift is zero. The further away from the center, the greater the Zeeman shift (the amplitude of the magneton energy level split), thus forming a position-dependent Zeeman shift. Moreover, along the same orthogonal direction, the splitting of the magneton energy levels is symmetrical with respect to the center of the magnetic field, meaning the directions of the Zeeman shifts are opposite.

[0055] In this case, by designing the polarization states of the six cooling beams (red detuned), a potential well for trapping atoms can be formed in conjunction with the aforementioned gradient magnetic field.

[0056] like Figure 1 As shown, taking one orthogonal direction Z as an example, the magnetic field center of the gradient magnetic field is set at the center position Z=0, where the magnetic field strength is zero. The magnetic field strength gradually increases as the gradient moves away from Z=0 along the -Z and +Z directions. Furthermore, the magnetic field directions are opposite on both sides of the magnetic field center (+Z side and -Z side). In this case, the excited state (J=1) of the atom has magneton energy levels (denoted by M) on both sides of the magnetic field center. JTaking the magnetic level as an example, the splitting is also symmetrical, making the transition of the atom Δm = -1 on the -Z side closer to that of the cooling light (…). Figure 1 The resonance condition (taking ω0 as an example) is closer to the resonance condition of the cooling light on the +Z side; the transition of the atom Δm=+1 is closer to the resonance condition of the cooling light.

[0057] To address the above situation, cooling light with σ-polarization and σ+polarization is incident on the orthogonal direction Z. It should be noted that in scenarios such as magneto-optical traps where atoms transition in a magnetic field, σ-polarization and σ+polarization are typically used to represent the polarization state of the cooling light, corresponding to the change in electron angular momentum during atomic transitions. Specifically, the polarization state matching the increase in electron angular momentum (Δm = +1) during atomic transitions is σ+polarization, and the polarization state matching the decrease in electron angular momentum (Δm = -1) during atomic transitions is σ-polarization.

[0058] Please continue to refer to this. Figure 1 This causes σ+ polarized cooling light to propagate from the -Z side towards the magnetic field center (Z=0), and σ- polarized cooling light to propagate from the +Z side towards the magnetic field center (Z=0). Atoms on the -Z side are more likely to absorb cooling light (σ+ polarized) propagating towards the magnetic field center, and atoms on the +Z side are more likely to absorb cooling light (σ- polarized) propagating towards the magnetic field center, thus generating a scattering force pointing towards the magnetic field center. Furthermore, the position-dependent Zeeman shift can be converted into a position-dependent resonance condition (where the detuning of the cooling light varies with position). This position-dependent resonance condition allows the atom to scatter the cooling light more efficiently the further away from the magnetic field center, resulting in a stronger scattering force pointing towards the magnetic field center. This makes it easier for the atom to be "kicked" back to the magnetic field center by photons, forming a potential well that traps the atom in this orthogonal direction Z.

[0059] Extending the above design to three-dimensional orthogonal directions can form a potential well that traps atoms in three-dimensional space.

[0060] As described above, the magneto-optical trap achieves atomic cooling by forming optical clusters from six beams of cooling light emanating from three orthogonally aligned directions, significantly reducing atomic velocity. This cooling can reach extremely low temperatures on the order of millikelvin (mK) or even hundreds of microkelvin (μK). Furthermore, through the combination of a gradient magnetic field and cooling light with specific polarization states, a potential well is formed in space to trap atoms, thus confining them within the optical clusters and allowing for continuous cooling.

[0061] like Figure 2As shown, a magneto-optical trap device 1 provided in related technologies includes a vacuum cavity 3, a pair of anti-Helmholtz coils 6, and an optical system 2. The vacuum cavity 3 is used to house the target atom 4 of the magneto-optical trap device 1. The pair of anti-Helmholtz coils 6 are disposed outside the vacuum cavity 3, positioned on either side of a plane of symmetry parallel to the first direction X and the second direction Y, and symmetrically arranged with respect to the plane of symmetry in a third direction Z; wherein the first direction X, the second direction Y, and the third direction Z are mutually perpendicular three-dimensional orthogonal directions.

[0062] The magnetic field lines generated by the pair of anti-Helmholtz coils 6 converge on the plane of symmetry and diverge in the third direction Z, creating a gradient magnetic field in the vacuum cavity 3 with its center located in the plane of symmetry. The magnetic field strength of this gradient magnetic field is zero at the center and gradually increases as it moves away from the center. Furthermore, in the first direction X and the second direction Y, the magnetic field directions of the gradient magnetic fields on both sides of the center of the magnetic field both point towards the center; while in the third direction Z, the magnetic field directions of the gradient magnetic fields on both sides of the center of the magnetic field both move away from the center.

[0063] The optical system 2 is located outside the vacuum cavity 3 and is used to generate six beams of cooling light 5 that irradiate the vacuum cavity 3. The six beams of cooling light 5 are irradiated in pairs in the first direction X, the second direction Y and the third direction Z to form an optical clump whose center position coincides with the center of the magnetic field. The optical clump is located in the vacuum cavity 3 and is used to decelerate and cool the target atom 4 in the vacuum cavity 3.

[0064] To facilitate the generation of a potential well trapping the target atom 4 using the gradient magnetic field, the polarization states of the six beams of cooling light 5 generated by the optical system 2 require special design. Specifically, the cooling light 5 incident in the first direction X and the second direction Y is left-handed circularly polarized, while the cooling light 5 incident in the third direction Z is right-handed circularly polarized. Here, left-handed and right-handed circular polarization are relative to an observer facing the propagation direction; right-handed polarization occurs when the electric field vector rotates clockwise, and left-handed polarization occurs when the electric field vector rotates counterclockwise. Left-handed circularly polarized light, when incident in the first direction X and the second direction Y, can be used for σ- and σ+ polarization; right-handed circularly polarized light, when incident in the third direction Z, can also be used for σ- and σ+ polarization.

[0065] However, in the aforementioned magneto-optical trap device 1 provided by related technologies, the heat dissipation of the anti-Helmholtz coil 6 and the required magnetic field strength are mutually constrained, resulting in a large coil volume and a large overall device structure, making miniaturization and integration difficult. Furthermore, the anti-Helmholtz coil 6 and its mounting structure obstruct the optical path of the cooling light 5, thus limiting the illumination direction and position of the cooling light 5, increasing design and manufacturing complexity. Moreover, the anti-Helmholtz coil 6 also has the problem of residual magnetic fields, requiring additional devices to eliminate them, further complicating the structure.

[0066] Based on this, embodiments of this application provide a magneto-optical trap device to improve the above-mentioned problems.

[0067] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0068] In the following embodiments of this application, the terms "first," "second," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0069] In the embodiments of this application, "upper", "lower", "left" and "right" are not limited to the orientation of the components in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0070] In the embodiments of this application, unless the context otherwise requires, the term "comprising" is interpreted as open and encompassing throughout the specification and claims, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "exemplarily," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0071] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0072] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0073] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0074] Exemplary embodiments are described in this application with reference to cross-sectional views and / or plan views and / or equivalent circuit diagrams, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0075] This application provides a magneto-optical trap device that can be used to cool and trap target atoms. The target atoms include neutral atoms such as alkali metal atoms, alkaline earth metal atoms, rare earth atoms, and rare gas atoms. Alkali metal atoms are, for example, rubidium (Rb), cesium (Cs), sodium (Na), and potassium (K); alkaline earth metal atoms are, for example, strontium (Sr), calcium (Ca), and barium (Ba); rare gas atoms are, for example, helium (He) and neon (Ne); and rare earth atoms are, for example, ytterbium (Yb) and erbium (Er).

[0076] like Figure 3 As shown, the magneto-optical trap device 1 includes a vacuum cavity 3 and an optical system 2. The vacuum cavity 3 is used to house the target atom 4 that the magneto-optical trap device 1 acts upon. The optical system 2 is located outside the vacuum cavity 3 and is used to generate three pairs (six beams) of cooling light 5 projected in opposite directions X, Y, and Z; wherein the X, Y, and Z directions are mutually perpendicular three-dimensional orthogonal directions. The three pairs (six beams) of cooling light 5 intersect at the same location, referred to herein as the trap center position O, which is located within the vacuum cavity 3. The three pairs (six beams) of cooling light 5 can form optical clusters at the trap center position O for decelerating and cooling the atom.

[0077] Further descriptions of the three pairs (six beams) of cooling light 5 can be found above and will not be repeated here.

[0078] The optical system 2 is also used to generate magnetic field light 8, which can produce an equivalent magnetic field on the target atom 4. To facilitate understanding of the technical solution provided in the embodiments of this application, the principle of the magnetic field light 8 generating an equivalent magnetic field on the target atom 4 will be briefly explained below.

[0079] When a target atom is placed in a light field, it experiences a dipole potential from the light field. This atom-light field interaction causes the atomic energy levels of the target atom to shift or split; this phenomenon is called optical displacement. Optical displacement can be decomposed into three parts: scalar optical displacement, vector optical displacement, and tensor optical displacement. The vector optical displacement is caused by the circular polarization component in the light field. Under the same light field, the quantum number m... F Different magneton energy levels produce different vector light shifts; quantum number m F The larger the magnetic quantum energy level, the greater the vector light shift. This will be discussed in this paper in relation to the quantum number m. F The corresponding magnetic level is called m F Magnetic quantum level. It should be noted that in some cases, the quantum number can also be expressed as m. J Characterization, with quantum number m J The corresponding magnetic level is m J Magnetic level.

[0080] Based on the description of the Zeeman effect above, both light fields and external magnetic fields can cause the magnetic sublevels of atoms to split. When a suitable light beam irradiates a target atom, the same energy level splitting effect (Zeeeman effect) as that of an external magnetic field can be produced by controlling the vector light displacement. This effect of the light beam can also be considered as producing an "equivalent magnetic field" to the target atom. In this paper, the light beam that can produce an equivalent magnetic field to the target atom is called magnetic field light.

[0081] Taking alkali metal atoms, commonly used in cold atom experiments, as an example, the tensor shift is 0 in the ground state of alkali metal atoms. The absorption spectral line corresponding to the lowest excited state of an alkali metal atom is the D-line, located in the visible to near-infrared band. The D-line is further subdivided into D1 and D2 line pairs, corresponding to the transitions between the two fine energy levels from the ground state to the first excited state. When alkali metal atoms are irradiated with circularly polarized light (σ-polarized) at wavelengths between the D1 and D2 lines, the scalar optical shifts to the ground state have opposite signs, while the vector optical shifts have the same sign. Furthermore, there is a wavelength between the D1 and D2 lines where, under circularly polarized light irradiation, the scalar optical shift to the ground state is exactly 0, while the vector optical shifts are superimposed. This wavelength is called the "tune-out wavelength."

[0082] Therefore, circularly polarized light (σ-polarized or σ+polarized) with a phantom zero wavelength can be used as the magnetic field light. When the magnetic field light irradiates alkali metal atoms, the displacement of the vector light can be controlled, thereby generating an equivalent magnetic field on the alkali metal atoms.

[0083] To verify the above principle and effect, magnetic field light was used to examine potassium atoms in alkali metal atoms. 39 K, rubidium atoms 87 Rb and cesium atoms 133 Cs was used for irradiation, and the energy level splitting of the atoms was measured. Among them, potassium atoms... 39 The magic zero wavelength of K is 769 nm, and the rubidium atom... 87 The magic zero wavelength of Rb is 790 nm, and the cesium atom... 133 The magic zero wavelength of Cs is 878.5 nm. The magnetic field light uses circularly polarized light (σ-polarized) with the magic zero wavelength and a power density of 1 mW*μm. -2 When a magnetic field light irradiates the corresponding alkali metal atom, the potassium atom... 39 K, rubidium atoms 87 Rb and cesium atoms 133 The energy level splitting result of the ground state of Cs is as follows: Figure 4 As shown.

[0084] from Figure 4 The results show that, under the irradiation of their respective magnetic field lights, potassium atoms 39 K, rubidium atoms 87 Rb and cesium atoms 133 Cs's neighboring m F Magnetic level splitting of a certain size can occur between magnetic levels, and different m F The splitting amplitude of the magneton energy level and the quantum number m F Positive correlation.

[0085] The above description and measurement experiments show that a specially designed magnetic field can induce energy level splitting in the ground state of alkali metal atoms, and different m F The splitting amplitude of the magneton energy level and the quantum number m F Positive correlation. This effect is the same as the Zeeman effect caused by an external magnetic field. Therefore, the energy level splitting effect of this magnetic field light on alkali metal atoms can be equated to the effect of an external magnetic field, that is, it produces an equivalent magnetic field on alkali metal atoms.

[0086] For scenarios where magnetic field light generates an equivalent magnetic field on target atoms, the splitting amplitude of the atomic energy levels by the magnetic field light can also be represented by the equivalent magnetic field strength. That is, the splitting amplitude of the energy levels by the magnetic field light is represented by the magnetic field strength of an external magnetic field capable of producing the same energy level splitting effect. For example, in the experiment mentioned above, the magnetic field light on rubidium atoms... 87 Rb's neighboring m F A 29.5 MHz energy level split can be generated between magnetic sublevels, with an equivalent magnetic field strength of 42 G. In other words, the aforementioned magnetic field light affects rubidium atoms. 87 The energy level splitting effect produced by Rb and the effect of an external magnetic field with a strength of 42 G on rubidium atoms 87 The energy level splitting effect produced by Rb is the same.

[0087] Magnetic field light pair m F The splitting amplitude of the magnetic quantum energy level is also positively correlated with the light intensity; the greater the light intensity, the greater the splitting amplitude; the smaller the light intensity, the smaller the splitting amplitude. Therefore, the magnetic field light intensity can be controlled by gradually varying the light intensity along the propagation direction. For example, using a Gaussian beam, Laguerre-Gaussian beam, super-Gaussian beam, or Airy beam, where the intensity gradually varies along the propagation direction, can be used as the magnetic field light to achieve the desired effect. F The splitting amplitude of the magnetic quantum energy level gradually changes in the direction of propagation of the magnetic field light, thus achieving the same effect as a gradient magnetic field.

[0088] For example, the magnetic field light is a circularly polarized (σ-polarized) Gaussian beam with an optical power of 600mW, a beam waist radius of 50μm, a Rayleigh length of 10mm, and a power density of 0.15mW*m at the beam waist. -2 Rubidium atoms were irradiated with the aforementioned magnetic field light. 87 Rb, magnetic field light on rubidium atoms 87 The relationship between the equivalent magnetic field strength and equivalent magnetic field gradient generated by Rb and its position in the propagation direction is as follows: Figure 5 As shown. From Figure 5 It can be seen from this that the magnetic field light affects rubidium atoms 87 The equivalent magnetic field generated by Rb has the largest intensity at the waist of the beam (the position with coordinate 0), which is approximately 4.15 G. Furthermore, as the beam moves away from the waist along the propagation direction, the intensity of the equivalent magnetic field gradually decreases, thus generating an "equivalent" gradient magnetic field.

[0089] As can be seen from the above, using appropriate magnetic field light can generate an equivalent magnetic field on the target atom, and by controlling the light intensity of the magnetic field light to gradually change in the propagation direction, an equivalent gradient magnetic field can be generated.

[0090] Please combine Figure 3 and Figure 6 Based on the principle of generating an equivalent magnetic field from the above magnetic field light, in the magneto-optical trap device 1 provided in this application embodiment, the optical system 2 is also used to generate three pairs (six beams) of magnetic field light 8 that are directed in the first direction X, the second direction Y and the third direction Z and intersect at the trap center position O. The three pairs (six beams) of magnetic field light 8 are transmitted in the same direction as the above three pairs (six beams) of cooling light 5 and their optical paths overlap.

[0091] The three pairs (six beams) of magnetic field light 8 generated by optical system 2 are all circularly polarized light with wavelengths that are the phantom zero wavelengths of the target atom 4. For example, this applies to potassium atoms. 39 The magnetic field light of K has a wavelength of 769 nm and targets rubidium atoms. 87 The magnetic field light of Rb has a wavelength of 790 nm and targets cesium atoms. 133 The magnetic field light wavelength for Cs is 878.5 nm, while the magnetic field light wavelength for lithium atoms is 670 nm.

[0092] like Figure 6 As shown, each magnetic field beam 8 employs a beam with intensity varying gradients along the propagation direction, such as a Gaussian beam, a Laguerre-Gaussian beam, a super-Gaussian beam, or an Airy beam. When using such beams, the beam waist of the magnetic field beam 8 is located on the incident side relative to the center O of the trap. This allows the intensity of the magnetic field beam 8 to gradually decrease as it moves closer to the center O of the trap from the beam waist along the propagation direction. Consequently, the equivalent magnetic field strength of the equivalent magnetic field 9 formed by the magnetic field beam 8 gradually decreases as it moves closer to the center O of the trap from the beam waist along the propagation direction.

[0093] As described above regarding magneto-optical traps, the gradient magnetic fields on both sides of the magnetic field center are symmetrical in the same orthogonal direction. To achieve the above effect, such as... Figure 6 and Figure 7 As shown, two beams of magnetic field light can be directed at each other in opposite directions. In the same orthogonal direction ( Figure 7 Taking the first direction X as an example, the two opposing magnetic field beams 8 are the first beam 11 and the second beam 10, respectively. The first beam 11 and the second beam 10 are circularly polarized light with the same rotation direction, and their intensity gradually decreases as they approach the center position O of the trap along the transmission direction. This design can generate an equivalent gradient magnetic field with the same symmetry as the anti-Helmholtz coil 6, in which the energy levels of the atom split symmetrically.

[0094] In some embodiments, the waist positions of the first beam 11 and the second beam 10 can be controlled to ensure the uniformity of the magnetic field gradient of the equivalent magnetic field 9 and that the equivalent magnetic field strength meets the requirements of the magneto-optical trap device 1. The target atom 4 is still considered to be a rubidium atom. 87 Taking Rb as an example, two magnetic field beams 8 (first beam 11 and second beam 10) are directed against each other. Both magnetic field beams 8 (first beam 11 and second beam 10) are circularly polarized Gaussian beams with the same direction of rotation. The optical power is 600mW, the beam waist radius is 50μm, the Rayleigh length is 10mm, and the power density at the beam waist is 0.15mW*m. -2 By controlling the beam waist spacing of two magnetic field beams 8 (first beam 11 and second beam 10) at different distances, the equivalent magnetic field strength and equivalent magnetic field gradient in the opposite direction are measured, and the results are as follows. Figure 8 As shown. (Through) Figure 8 As can be seen, for the two opposing magnetic field beams 8 (the first beam 11 and the second beam 10), the equivalent magnetic field strength reaches two opposite maximum values ​​at the two beam waist positions. When the beam waist spacing of the two opposing magnetic field beams 8 (the first beam 11 and the second beam 10) is equal to twice the Rayleigh length (i.e., 20 nm, corresponding to curve 2), the magnetic field gradient at the middle position is the most uniform. Under this condition, a gradient magnetic field of 6.4 G / cm can be obtained, which is comparable to the gradient generated by a pair of anti-Helmholtz coils 6 in the magneto-optical trap device 1 in the related technology.

[0095] The beam waist spacing of the first beam 11 and the second beam 10 is also related to factors such as the energy level structure of the target atom 4 and the beam parameters. Typically, the beam waist spacing of the first beam 11 and the second beam 10 is 1 to 3 times the Rayleigh length. This design ensures that the equivalent magnetic field strength of the generated equivalent gradient magnetic field is zero at the center of the magnetic field, and that the equivalent magnetic field strength increases uniformly as the distance from the center of the magnetic field increases.

[0096] In some embodiments, such as Figure 6 As shown, for three-dimensional orthogonal directions, the magnetic field light 8 projected in two orthogonal directions and the magnetic field light 8 projected in another orthogonal direction are circularly polarized with different rotation directions. This design can make the generated equivalent magnetic field a source-free field, which is the same as the magnetic field generated by a pair of anti-Helmholtz coils 6.

[0097] To create a potential well for trapping target atom 4 in conjunction with the equivalent magnetic field, the polarization relationship between cooling light 5 and magnetic field light 8 also needs to be designed. Specifically, for cooling light 5 and magnetic field light 8, which propagate in the same orthogonal direction, circularly polarized light with different rotation directions is used. This design ensures that as target atom 4 moves away from the center position O of the well, it experiences a scattering force generated by cooling light 5, which points towards the center position O; and the scattering force increases with distance from the center position O.

[0098] The magneto-optical trap device 1 provided in this application can generate an equivalent magnetic field on the target atom 4 by using a specially designed magnetic field light 8, achieving the same effect as the anti-Helmholtz coil 6, thus enabling the design of an all-optical magneto-optical trap. This design avoids the problems of large size and residual magnetic field associated with the anti-Helmholtz coil 6, significantly simplifying the device and facilitating its miniaturization and integration. Furthermore, the optical paths of the magnetic field light 8 and the cooling light 5 overlap, without occupying an additional optical path; this avoids the problem of the anti-Helmholtz coil 6 blocking the optical path of the cooling light 5, allowing for greater freedom in the illumination direction and position of the cooling light 5, and reducing the design and fabrication difficulty of the magneto-optical trap device 1.

[0099] In addition, the total power of the magnetic field light 8 required to generate the same gradient magnetic field as the anti-Helmholtz coil 6 using the above scheme is in the order of several watts, so it can be easily achieved using existing mature and low-cost laser sources.

[0100] In some embodiments, such as Figure 3 As shown, the optical system 2 includes six first subsystems 7, which are located on both sides of the center position O of the trap in three-dimensional orthogonal directions. Each first subsystem 7 is used to generate cooling light 5 and magnetic field light 8 that are transmitted in the same direction toward the center position O of the trap along the corresponding orthogonal direction.

[0101] like Figure 9 As shown, taking the first subsystem 7 located on both sides of the center position O of the trap in the first direction X as an example, the first subsystem 7 includes a cooling optical component 12, a magnetic field optical component 16, and a first beam splitting and combining device 15.

[0102] The cooling light assembly 12 generates cooling light 5 and includes a first light source 14 and a first polarization conversion device 13. The first light source 14 generates cooling light 5 in a first polarization state, and the first polarization conversion device 13 converts the cooling light 5 in the first polarization state into circularly polarized light with a first rotation direction. The magnetic field light assembly 16 generates magnetic field light 8 and includes a second light source 17, a first converging lens 19, and a second polarization conversion device 18. The second light source 17 generates magnetic field light 8 in a second polarization state, and the first converging lens 19 converges the magnetic field light 8 to control the beam waist position of the magnetic field light 8. The second polarization conversion device 18 converts the magnetic field light 8 into circularly polarized light with a second rotation direction.

[0103] The first beam splitting and combining device 15 is used to combine the cooling light 5 generated by the cooling light component 12 and the magnetic field light 8 generated by the magnetic field light component 16, and transmit the combined cooling light 5 and magnetic field light 8 towards the center position O of the trap along the orthogonal direction.

[0104] In some embodiments, the first polarization state and the second polarization state are orthogonal linear polarizations, the first polarization conversion device 13 and the second polarization conversion device 18 are the same quarter-wave plate, and the quarter-wave plate is located on the exit side of the first beam splitter / combiner 15. For example, the first polarization state is one of P-polarization and S-polarization, the second polarization state is the other of P-polarization and S-polarization, and the first beam splitter / combiner 15 is a polarization beam splitter (PBS). This design simplifies the structure and saves costs.

[0105] For the other first subsystems 7, the design can be based on the first subsystem 7 described above, as well as the requirements for the magnetic field light 8 and the cooling light 5, and will not be elaborated here. For the six first subsystems 7 in the optical system 2, their first light source 14 can share a single light source, and their second light source 17 can also share a single light source, thereby simplifying the structure and saving costs.

[0106] In some embodiments, such as Figure 10 As shown, the optical system 2 includes a first subsystem 7 and a second subsystem 20 located on either side of the well center position O in any orthogonal direction. That is, the optical system 2 includes three first subsystems 7 and three second subsystems 20, arranged in pairs. The paired first subsystems 7 and 20 are located on either side of the well center position O in the same orthogonal direction. The first subsystem 7 is used to generate cooling light 5 and magnetic field light 8 that propagate in the same direction toward the well center position O along the corresponding orthogonal direction. A description of the first subsystem 7 can be found above and will not be repeated here.

[0107] The second subsystem 20 is used to reflect the cooling light 5 and the magnetic field light 8. The reflected cooling light 5 and magnetic field light 8 are transmitted in the same direction toward the center position O of the trap along their orthogonal directions. With this design, the cooling light 5 and the magnetic field light 8 that are projected in the orthogonal direction can still be formed. Moreover, compared with the method of using the first subsystem 7, the combination of the first subsystem 7 and the second subsystem 20 has advantages such as low cost and simple structure.

[0108] For example, such as Figure 11 As shown, compared to the first subsystem 7, the second subsystem 20 is equivalent to replacing the first light source 14 with the first reflecting device 22, and replacing the second light source 17 with the second reflecting device 23. Specifically, the second subsystem 20 includes the first reflecting device 22, the second reflecting device 23, the third polarization conversion device 21, the second beam splitting and combining device 25, and the second converging lens 24. The functions and locations of each part of the second subsystem 20 will be described below in conjunction with the working process.

[0109] In the second subsystem 20, the third polarization conversion device 21 is used to convert the cooling light 5 from circularly polarized light with a first rotation direction to a first polarization state, and to convert the magnetic field light 8 from circularly polarized light with a second rotation direction to a second polarization state, so as to facilitate the beam splitting and combining operation of the second beam splitting and combining device 25. The second beam splitting and combining device 25 is used to split the cooling light 5 with the first polarization state and the magnetic field light 8 with the second polarization state, and guide the cooling light 5 to the first reflecting device 22 and the magnetic field light 8 to the second reflecting device 23.

[0110] The first reflecting device 22 is used to reflect the cooling light 5 back to the second beam splitting and combining device 25 along the original path. The second reflecting device 23 is used to reflect the magnetic field light 8 back to the second beam splitting and combining device 25 along the original path. The second beam splitting and combining device 25 is also used to combine the cooling light 5 reflected back by the first reflecting device 22 and the magnetic field light 8 reflected back by the second reflecting device 23, and transmit the combined cooling light 5 and magnetic field light 8 towards the center position O of the trap along the orthogonal direction.

[0111] The third polarization conversion device 21 is also used to convert the reflected cooling light 5 from the first polarization state to circularly polarized light with the first rotation direction, and to convert the reflected magnetic field light 8 from the second polarization state to circularly polarized light with the second rotation direction.

[0112] In the second subsystem 20, the second converging lens 24 is used to converge the magnetic field light 8 to control the position of the beam waist of the magnetic field light 8. The second converging lens 24 may be disposed, for example, between the second reflecting device 23 and the second beam splitting and combining device 25.

[0113] In some embodiments, such as Figure 12 As shown, the magnetic field light component 16 in the first subsystem 7 also includes a beam splitter 26. This beam splitter 26 can be disposed on the light-incoming side of the first converging lens 19, or between the first converging lens 19 and the second polarization conversion device 18; it is used to split the magnetic field light 8 into multiple parallel-transmitting sub-magnetic field lights. In the magneto-optical trap device 1, as... Figure 13 As shown, the multiple beams of submagnetic field light 28 generated by the optical system 2 intersect at different positions in three-dimensional space, thereby forming multiple micro-gradient magnetic fields located at different positions in three-dimensional space within the optical aggregate. These magnetic fields, in conjunction with the cooling light 5, can form multiple micro-magnetic-optical traps 27, which are arrayed in the first direction X, the second direction Y, and the third direction Z. This design can adapt to different application scenarios, and the spacing between the aforementioned micro-magnetic-optical traps 27 can be reduced to less than approximately 100 μm, which is difficult to achieve with magneto-optical traps using anti-Helmholtz coils.

[0114] In the above scheme, the beam splitter 26 can be a spatial light modulator (SLM). The spatial light modulator can not only achieve beam splitting, but also adjust the beam splitting situation, which is more flexible.

[0115] In some embodiments, the magneto-optical trap device 1 described above can be a miniaturized integrated product, integrated into a chip.

[0116] This application provides an atomic device 100, such as... Figure 14 As shown, the atomic device 100 includes a magneto-optical trap device 1 as described in the above embodiment and a processing device 110. The processing device 110 is used to process the target atom 4 cooled and trapped by the magneto-optical trap device 1. The atomic device 100 can be an atomic clock, an atomic interferometer gravimeter, an atomic gyroscope, or a neutral atom quantum computer, etc. In different atomic devices 100, the processing device 110 performs different functions on the target atom 4 in the magneto-optical trap device 1.

[0117] This application also provides a quantum computer, which is a neutral atom-based quantum computer, including the magneto-optical trap device 1 as described in the above embodiments. The target atoms cooled and trapped by the magneto-optical trap device 1 are neutral atoms required for quantum computing.

[0118] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A magneto-optical trap device, characterized in that, The magneto-optical trap device includes a vacuum cavity and an optical system; wherein the vacuum cavity is used to contain target atoms; The optical system is used to generate three pairs of cooling beams that are directed in three-dimensional orthogonal directions. The cooling beams are laser beams used to perform Doppler cooling on the target atoms. The three pairs of cooling beams intersect at the center of the trap to form an optical cluster at the center of the trap. The center of the trap is located in the vacuum cavity. The optical system is also used to generate three pairs of magnetic field lights that travel in the same direction as the three pairs of cooling lights, and the three pairs of magnetic field lights intersect at the center of the trap; the magnetic field lights are laser beams used to generate an equivalent magnetic field for the target atom, and the three pairs of magnetic field lights are used in conjunction with the three pairs of cooling lights to trap the target atom in the optical aggregate.

2. The magneto-optical trap device according to claim 1, characterized in that, Each pair of magnetic field lights includes a first beam and a second beam that are directed against each other in the same orthogonal direction. The first beam and the second beam are circularly polarized light with the same rotation direction, and their light intensity gradually decreases as they approach the center of the trap along the transmission direction.

3. The magneto-optical trap device according to claim 2, characterized in that, Both the first beam and the second beam are Gaussian beams.

4. The magneto-optical trap device according to claim 2 or 3, characterized in that, The waist positions of the first beam and the second beam are both located on the incident side relative to the center position of the trap, and the interval between the waist positions of the first beam and the second beam in the orthogonal direction is 1 to 3 times the Rayleigh length.

5. The magneto-optical trap device according to any one of claims 1 to 4, characterized in that, Of the three pairs of magnetic field lights, two pairs are circularly polarized light with a first rotation direction, and the other pair are circularly polarized light with a second rotation direction. Wherein, the first direction of rotation is either left-handed or right-handed, and the second direction of rotation is either left-handed or right-handed.

6. The magneto-optical trap device according to any one of claims 1 to 5, characterized in that, The cooling light and the magnetic field light, which are transmitted in the same direction, have different wavelengths and are circularly polarized light with opposite rotation directions.

7. The magneto-optical trap device according to claim 6, characterized in that, The optical system includes two first subsystems located on either side of the center of the well in the same orthogonal direction. The first subsystems are used to generate the cooling light and the magnetic field light that are transmitted in the same direction toward the center of the well along the orthogonal direction. Alternatively, the optical system may include a first subsystem and a second subsystem located on either side of the center of the trap in the same orthogonal direction. The first subsystem is used to generate the cooling light and the magnetic field light that are transmitted in the same direction toward the center of the trap along the orthogonal direction. The second subsystem is used to reflect the cooling light and the magnetic field light, and the reflected cooling light and the magnetic field light are transmitted in the same direction toward the center of the trap along the same orthogonal direction.

8. The magneto-optical trap device according to claim 7, characterized in that, The first subsystem includes a cooling optical component, a magnetic field optical component, and a first beam splitting and combining device; The cooling light assembly includes a first light source and a first polarization conversion device. The first light source is used to generate the cooling light in a first polarization state, and the first polarization conversion device is used to convert the cooling light into circularly polarized light in a first rotation direction. The magnetic field light component includes a second light source, a first converging lens, and a second polarization conversion device. The second light source is used to generate the magnetic field light in a second polarization state, the first converging lens is used to converge the magnetic field light, and the second polarization conversion device is used to convert the magnetic field light into circularly polarized light with a second rotation direction. The first beam splitting and combining device is used to combine the cooling light generated by the cooling light component and the magnetic field light generated by the magnetic field light component, and to transmit the combined cooling light and magnetic field light toward the center of the trap along their orthogonal directions.

9. The magneto-optical trap device according to claim 8, characterized in that, The first polarization state and the second polarization state are orthogonal linear polarizations, the first polarization conversion device and the second polarization conversion device are the same quarter-wave plate, and the quarter-wave plate is located on the output side of the beam combiner.

10. The magneto-optical trap device according to claim 9, characterized in that, The first polarization state is one of P polarization and S polarization, the second polarization state is the other of P polarization and S polarization, and the first beam splitting and combining device is a polarization beam combiner.

11. The magneto-optical trap device according to any one of claims 7 to 10, characterized in that, The second subsystem includes a second beam splitter / combiner, a first reflector, a second reflector, and a second converging lens; The second beam splitting and combining device is used to split the cooling light and the magnetic field light that are transmitted in the same direction, and guide the cooling light to the first reflecting device and the magnetic field light to the second reflecting device; The first reflecting device is used to reflect the cooling light, and the second reflecting device is used to reflect the magnetic field light; The second beam splitting and combining device is also used to combine the cooling light reflected by the first reflecting device and the magnetic field light reflected by the second reflecting device, and to transmit the combined cooling light and the magnetic field light toward the center of the trap along the orthogonal direction. The second converging lens is used to converge the magnetic field light.

12. The magneto-optical trap device according to any one of claims 7 to 11, characterized in that, The first subsystem further includes a beam splitter for splitting the magnetic field light into multiple parallel sub-magnetic field lights.

13. The magneto-optical trap device according to claim 12, characterized in that, The beam splitter is a spatial light modulator.

14. The magneto-optical trap device according to any one of claims 1 to 13, characterized in that, The target atom is a rubidium atom, and the wavelength of the magnetic field light is 790 nm; Alternatively, the target atom may be a potassium atom, and the wavelength of the magnetic field light may be 769 nm. Alternatively, the target atom is a lithium atom, and the wavelength of the magnetic field light is 670 nm; Alternatively, the target atom may be a cesium atom, and the wavelength of the magnetic field light may be 878.5 nm.

15. An atomic device, characterized in that, The atomic device includes: The magneto-optical trap device as described in any one of claims 1 to 14; and A processing device for processing target atoms cooled and trapped by the magneto-optical trap device.

16. A quantum computer, characterized in that, The quantum computer includes a magneto-optical trap device as described in any one of claims 1 to 14.

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