A high-beam low-speed selective cold atomic source generating device and experimental device

Abstract

The application discloses a high-beam low-speed selective cold atom source generating device and an experimental device. The generating device comprises an atom furnace, a Zeman decelerator, a transverse cooler and a hot window which are coaxially arranged in a vacuum cavity in sequence. At least one low-speed selector is arranged between the transverse cooler and the hot window. The zero magnetic field axis of the low-speed selector and the direction of the atomic beam moving out of the atom furnace have an included angle. An optical unit makes the low-speed atomic beam run along the direction of the zero magnetic field axis of the low-speed selector and enter a vacuum differential tube. In the application, the Zeman decelerator and the transverse cooler are designed to be small in size, and are used for decelerating and cooling high-speed atoms, so that the number of low-speed atoms is effectively increased. The low-speed selector is used for screening the low-speed atoms to the direction of the zero magnetic field axis and into a scientific experiment main cavity. The selected speed laser is used for forming an optical field in the low-speed selector, so that the low-speed atomic beam flow in the vacuum differential tube is switched.

Description

Technical Field

[0001] This invention relates to an atomic source device, specifically a portable and integrated high-current, low-speed selective cold atomic source generator and experimental apparatus. Background Technology

[0002] An optical lattice clock is a type of atomic clock based on the time and frequency measurement of cold atomic gases. It uses the vibration of electrons within atoms as its oscillator; if the vibration frequency falls within the light spectrum, the clock is called an optical clock, and an optical lattice clock is a type of optical clock. In the last decade, neutral atom optical lattice clocks have made breakthroughs in frequency uncertainty and stability, especially strontium atom optical lattice clocks, whose frequency uncertainty and stability have reached the tens of thousands of seconds (E-18) level. Currently, optical lattice clocks are gradually moving towards portability, a prerequisite for which is the miniaturization and integrated design of atomic sources. Therefore, efficient and integrated atomic sources have become a current research hotspot.

[0003] For example, alkaline earth metals like strontium or alkali metals like rubidium are generally solid at room temperature. However, cold atom experiments require a cold atom gas. The role of the atom source device is to convert slowed-down atoms into a low-speed atom gas, preparing for loading into the magneto-optical trap and optical lattice of the main scientific cavity.

[0004] There are two commonly used technologies in atomic source design: Zeeman decelerators and two-dimensional magneto-optical traps. Among them, the traditional atomic source device based on Zeeman decelerator adopts a direct-connection design, in which the atomic gas directly enters the cold atom scientific main cavity after being decelerated by Zeeman. This design has many drawbacks, mainly: (1) The decelerated low-speed atoms and the undecelerated high-speed atoms do not undergo velocity selection and all enter the scientific main cavity. The high-speed atoms that enter will bring negative effects, such as increasing the heating effect caused by atomic collisions and reducing the lifetime of the optical lattice; (2) This device needs to be used with mechanical electric valves to control the opening and closing of the atomic source, which increases the risk of system operation and has a slow response speed; (3) The direct-connection design allows both high-speed and low-speed atoms to enter the scientific main cavity, which often limits the vacuum level of the atomic source to the vacuum level of the scientific main cavity, thereby reducing the lifetime of the optical lattice of the main cavity; (4) In the application of optical clock experiments, the direct-connection design causes the high-temperature atomic furnace to face the atomic sample directly, and the blackbody radiation effect generated by it greatly limits the stability and uncertainty of the optical clock experiment.

[0005] Atomic source devices based on two-dimensional magneto-optical traps employ a deflection design, which can avoid some of the problems associated with direct-connected atomic sources. However, a drawback of existing two-dimensional magneto-optical traps is the difficulty in simultaneously achieving low velocity and high flux. When the critical velocity of the two-dimensional magneto-optical trap is designed to be relatively low, the atomic flux cannot be very high.

[0006] Furthermore, both coil-type Zeeman reducers and coil-type two-dimensional magneto-optical traps require significant power consumption and are bulky, making miniaturization difficult. However, in practical engineering applications, there is an increasing demand for miniaturized and portable atomic source devices. Summary of the Invention

[0007] The purpose of this invention is to provide a portable and integrated high-current, low-speed selective cold atom source generator and experimental apparatus to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A high-current, low-speed selective cold atom source generator includes an atomic furnace, a Zeeman reducer, a transverse cooler, and a hot window arranged coaxially in a vacuum chamber. At least one low-speed selector is disposed between the transverse cooler and the hot window. A vacuum differential tube is provided along the zero magnetic field axis of the low-speed selector, and there is an angle between the zero magnetic field axis of the low-speed selector and the direction of motion of the atomic beam exiting the atomic furnace. The generator also includes an optical unit that directs the low-speed atomic beam along the zero magnetic field axis of the low-speed selector into the vacuum differential tube.

[0010] In a further embodiment, the optical unit includes a Zeeman decelerating beam, a transversely cooled laser, and a speed-selective laser. The Zeeman decelerating beam and the atomic beam enter the Zeeman decelerator in opposite directions and decelerate the atomic beam. The transversely cooled laser enters the transverse cooler to narrow the divergence angle of the low-speed atomic beam. The speed-selective laser causes the low-speed atomic beam located in the low-speed selector to move along the zero magnetic field axis of the low-speed selector and enter the vacuum differential tube. The on / off state of the real-time atomic beam flow entering the vacuum differential tube is controlled by controlling the on / off state of the speed-selective laser.

[0011] This invention combines a low-speed selector, a Zeeman decelerator, and a transverse cooler to obtain a high-flow-rate low-speed atomic beam. The velocity selection range of the atomic beam can be adjusted by modifying the magnetic field gradient of the low-speed selector, the size of the velocity-selective laser, and its frequency. Adjusting the frequency of the Zeeman decelerator light ensures that the decelerated atomic beam velocity falls within the velocity selection range of the low-speed selector; applying transverse cooling light increases the proportion of the atomic beam within the velocity selection range of the low-speed selector.

[0012] In a further embodiment, the vacuum chamber is a cylindrical stainless steel or titanium alloy pipe, and its interior is in a vacuum state; the atomic furnace, Zeeman reducer, transverse cooler, low-speed selector and hot window are respectively fixed inside the vacuum chamber.

[0013] The sidewall of the vacuum cavity is uniformly provided with multiple light-transmitting holes, and a vacuum window is installed on the light-transmitting hole to allow external light sources to enter; both ends of the vacuum cavity are provided with optical windows.

[0014] In a further embodiment, the vacuum chamber is connected to an external vacuum pump to maintain the internal vacuum of the vacuum chamber at 5×10⁻⁹ mba.

[0015] In a further embodiment, the atomic furnace is a high-temperature atomic furnace with an operating temperature of 25℃-650℃ and a temperature fluctuation of less than 0.1℃; the furnace chamber of the high-temperature atomic furnace is equipped with three layers of thermal shielding, so that the temperature of the outer wall of the high-temperature atomic furnace is below 60℃ when it is operating at high temperature.

[0016] In a further embodiment, the Zeeman reducer is internally equipped with a permanent magnet array to form a Zeeman magnetic field, which causes the high-speed atomic beam generated by the atomic furnace to be continuously slowed down to a low speed by the Zeeman decelerating light moving in the opposite direction in the Zeeman magnetic field.

[0017] In a further embodiment, the transverse cooler is located behind the Zeeman reducer or is built into the interior of the Zeeman reducer; a laser inlet communicating with its internal cavity is provided on the outer wall of the transverse cooler; there are four laser inlets, which are respectively arranged in two orthogonal directions perpendicular to the direction of atomic beam motion.

[0018] In a further embodiment, a high-temperature resistant light-transmitting lens is embedded inside the thermal window. The light-transmitting lens is made of sapphire or quartz material, and its operating temperature is 25℃-350℃ with a temperature fluctuation of less than 0.1℃. The heat shield is a cylindrical non-magnetic stainless steel material with a certain thickness.

[0019] The low-speed selector is a two-dimensional magneto-optical trap. Multiple low-speed selectors are provided and arranged in a cascaded manner. There is an angle between the zero magnetic field axis of each low-speed selector and the direction of atomic beam entry, and the zero magnetic field axis of the last low-speed selector coincides with the axis of the vacuum differential tube.

[0020] In a further embodiment, the atomic beam is formed by heating and spraying alkali metal or alkaline earth metal solids in an atomic furnace. The alkali metal solids include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr), while the alkaline earth metal solids include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

[0021] Another objective of this application is to provide a cold atom source experimental apparatus, comprising a cold atom source generating apparatus and an experimental chamber as described in claims 1-8, wherein the outlet of the vacuum differential tube (8) in the cold atom source generating apparatus is connected to the experimental chamber.

[0022] In a further embodiment, the experimental chamber is provided with at least one interface, each interface being connected to the outlet of a vacuum differential tube in one of the cold atom source generating devices; the types of atomic beams in each of the cold atom source generating devices may be the same or different.

[0023] The Zeeman reducer in this application is a physical device based on the Zeeman reduction principle. It has a permanent magnet array inside to form a Zeeman magnetic field. It uses laser to reduce the atomic beam from a high-speed state to a low-speed state. For example, the average atomic velocity at its entrance is about several hundred m / s, while the average atomic velocity at its exit can be reduced to 10 m / s.

[0024] This application integrates a high-temperature atomic furnace, a Zeeman reducer, a transverse cooler, and a low-speed selector to form an integrated and miniaturized atomic source device, capable of directly outputting high-flow-rate low-speed atomic gas. Furthermore, by adjusting the laser frequency parameters in the optical unit, it can... 88 Sr atomic source, 87 Sr atomic source, 86 Sr atomic source and 84 Switching between Sr atom sources. For 88 For Sr, the atomic flux after exiting the vacuum differential tube is 2 × 10⁻⁶. 9 Amounts / s or higher.

[0025] This application combines advantages such as miniaturization, portability, ease of operation, and low power consumption. Specifically:

[0026] In terms of miniaturization, mechanical structures such as high-temperature atomic furnaces, Zeeman reducers, transverse coolers, and low-speed selectors, as well as permanent magnets, are integrated into the vacuum chamber. The chamber consists of cylindrical stainless steel or titanium alloy pipes with a total length of less than 500 mm, resulting in a small overall size.

[0027] In terms of portability, it is easy to disassemble and install since only the outlet of the vacuum differential tube needs to be connected to the main cavity of the cold atom experiment. In addition, the installation of valves and other devices at the connection port of the main cavity of the cold atom experiment can ensure that the ultra-high vacuum of the main cavity is not affected when the cold atom source generating device is disassembled and installed.

[0028] In terms of ease of operation, simply inputting Zeeman deceleration light, transverse cooling laser, and speed-selective laser into the device will decelerate and cool the atomic beam, and then output a low-speed cold atomic beam.

[0029] In terms of low power consumption, the magnetic field of both the Zeeman reducer and the low-speed selector can be provided by a permanent magnet array, eliminating the need for an external current source.

[0030] In this application, the Zeeman decelerator can slow down atoms, reducing their velocity from the original velocity v0 to v1, thus dividing atoms into two ranges: one with a velocity greater than v1 and the other with a velocity lower than v1. This significantly increases the proportion of atoms with velocities lower than v1. The transverse cooler further aligns the low-velocity atoms, enhancing the effectiveness of the low-velocity selector. The low-velocity selector has the characteristic of velocity selection, where low-velocity atoms are deflected to the zero magnetic field axis and enter the vacuum differential tube, while high-velocity atoms cannot be effectively deflected to the zero magnetic field axis and travel directly in a straight line. Therefore, only low-velocity, cooler atoms can enter the main cavity of the scientific experiment, thereby avoiding the negative impact of high-velocity atoms.

[0031] This application does not require mechanical valves to switch the atomic beam on and off. Instead, it uses a speed-selective laser to enter the light field formed in the low-speed selector to switch the atomic beam entering the vacuum differential tube. Therefore, it has the switching and regulating characteristics of optically controlled atomic beams, with faster response speed and higher system stability.

[0032] The design in this application, which combines a low-speed selector with a vacuum differential tube, enables a very high vacuum level within the main scientific cavity. For example, even if the vacuum level of the atomic source is only on the order of 10⁻⁹ mbar, the main cavity can still be maintained at an ultra-high vacuum of 10⁻¹¹ mbar, thereby greatly increasing the lifetime of cold atoms in the main cavity and facilitating scientific experiments such as cold atom manipulation and quantum precision measurement.

[0033] In this application, at least one low-speed selector is provided between the high-temperature atomic furnace and the vacuum differential tube, so that the high-temperature atomic furnace is not directly facing the atoms in the scientific main cavity, which eliminates the blackbody radiation effect of the high-temperature atomic furnace on the atoms in the scientific main cavity.

[0034] In addition, this invention combines a Zeeman reducer and a transverse cooler to improve the atomic flux and effective deflection performance of the two-dimensional magneto-optical trap; combined with the design of a differential tube, it not only improves the velocity screening performance, but also the atomic collimation performance and the vacuum performance of the scientific main cavity. Attached Figure Description

[0035] Figure 1 This is a schematic diagram illustrating the principle of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0038] Figure 4 In Embodiment 1 of the present invention 88 The relationship between the loading rate of Sr blue magneto-optical trap and the parametric detuning and power of Zeeman decelerated light;

[0039] Figure 5 In Embodiment 1 of the present invention 88 The relationship between the loading rate of Sr blue magneto-optical trap and the parametric detuning and power of transverse cooling light;

[0040] Figure 6 In Embodiment 1 of the present invention 88 The relationship between the loading rate of Sr blue magneto-optical trap and the parametric detuning and power of 2D MOT rate-selective laser;

[0041] Figure 7 In Embodiment 1 of the present invention 88 The relationship between the blue magneto-optical trap loading rate of Sr and the furnace temperature;

[0042] Figure 8 This illustrates the effect of the low-speed selector on atoms at different speeds in Embodiment 1 of the present invention.

[0043] Figure 9 This describes the relationship between the critical speed of the low-speed selector and the speed-selective laser frequency in Embodiment 1 of the present invention.

[0044] Figure 10 This illustrates the relationship between the critical speed of the low-speed selector and the size of the speed-selective laser in Embodiment 1 of the present invention.

[0045] Figure 11 This illustrates the relationship between the Zeeman reducer, the transverse cooler, and the atomic velocity in Embodiment 1 of the present invention.

[0046] In the diagram: 1-atomic furnace; 2-Zeeman reducer; 3-lateral cooler; 4-low speed selector; 5-speed selective laser; 6-Zeeman decelerated beam; 7-thermal window; 8-vacuum differential tube; 9-lateral cooling laser. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1:

[0049] Please see Figure 1 , 2In this embodiment of the invention, a portable, integrated high-current, low-speed selective cold atom source generator includes an atomic furnace 1, a Zeeman reducer 2, a transverse cooler 3, and a hot window 7 arranged coaxially in a vacuum cavity. A low-speed selector 4 is disposed between the transverse cooler 3 and the hot window 7. A vacuum differential tube 8 is provided in the zero magnetic field axis direction of the low-speed selector 4, and there is an angle between the zero magnetic field axis of the low-speed selector 4 and the direction of motion of the atomic beam exiting the atomic furnace 1. The generator also includes an optical unit, which guides the low-speed atomic beam along the zero magnetic field axis direction of the low-speed selector 4 into the vacuum differential tube 8, while the high-speed atomic beam continues to travel in its original direction.

[0050] Figure 1 In this context, v0 represents the initial velocity of the atomic beam, v1 represents the final velocity of the atomic beam after it has been decelerated, θ represents the final deflection angle of the low-speed atomic beam entering the vacuum differential tube, and θ1, ..., θn represent the deflection angles of each stage of the low-speed selector.

[0051] like Figure 2 , 8 As shown, in this embodiment, the high-speed atomic beam generated by the atomic furnace 1 is decelerated and cooled by the Zeeman reducer 2 and the transverse cooler 3. Atomic beams with speeds below 60 m / s are selected by the low-speed selector 4 and enter the vacuum differential tube 8, while atomic beams with speeds above 60 m / s continue to travel along their original straight line. That is, the low-speed selector is selective for atoms with different speeds, effectively selecting the atomic velocities.

[0052] In practical work, the velocity of the decelerated atomic beam can be adjusted by changing the shape of the Zeeman magnetic field in the Zeeman reducer, according to the actual needs of the cold atom experiment. The final cold atom velocity can be selected based on the specific circumstances, including the number and angle of the low-speed selector and the power of the speed-selective laser. For example... Figure 9 , 10 As shown, by controlling the frequency or size of the speed-selective laser, the critical speed of the low-speed selector can be adjusted to achieve a custom speed selection function.

[0053] In a further embodiment, the optical unit includes a Zeeman decelerating beam 6, a transversely cooled laser 9, and a speed-selective laser 5. The Zeeman decelerating beam 6 and the atomic beam enter the Zeeman decelerator 2 in opposite directions and decelerate the atomic beam. The transversely cooled laser 9 enters the transverse cooler 3 and narrows the divergence angle of the atomic beam therein. The speed-selective laser 5 causes the low-speed atomic beam located in the low-speed selector 4 to move along the axial direction of the low-speed selector 4 and enter the vacuum differential tube 8. The on / off state of the real-time atomic beam flow entering the vacuum differential tube 8 is controlled by controlling the on / off state of the speed-selective laser 5.

[0054] Even if the atomic beam entering the vacuum differential tube is switched on and off using the optical field formed by the speed-selective laser entering the low-speed selector, it eliminates the need for mechanical valves to switch the atomic beam, resulting in faster response speed and higher system stability. The Zeeman reducer in this application is a physical device based on the Zeeman reduction principle. It contains an array of permanent magnets forming a Zeeman magnetic field, which continuously slows the high-speed atomic beam generated by the atomic furnace 1 to a low-speed state by the Zeeman-reducing light 6 moving in the opposite direction within the Zeeman magnetic field. That is, the Zeeman-reducing light 6 reduces the atomic beam from a high-speed state to a low-speed state, decreasing the atomic velocity from the original velocity v0 to v1, dividing the atoms into two ranges with velocities greater than v1 and lower than v1, significantly increasing the effective proportion of low-speed atoms. The velocities v0 and v1 depend on the shape of the Zeeman magnetic field in the Zeeman reducer, which can be adjusted by the permanent magnet array. For miniaturization, a smaller v0 significantly simplifies the size of the Zeeman reducer and greatly reduces the power requirement of the Zeeman-reducing light. In this embodiment, the initial velocity v0 of the generated atomic beam can be set to 40-260 m / s, and the velocity v1 of the decelerated atomic beam is less than 40 m / s. Lateral cooling lasers can further improve the collimator for low-velocity atoms, allowing the low-velocity selector to work more effectively. Since v1 is already very low, the power and size requirements of the lateral cooling laser are reduced. Then, the low-velocity selector selects the velocities of the atoms; atoms with velocities below v1 are deflected towards the zero magnetic field axis and enter the vacuum differential tube; while atoms with velocities above v1 cannot be effectively deflected towards the zero magnetic field axis and travel directly in a straight line. Figure 11 As shown, the atomic deceleration range can be finely adjusted by controlling the frequency of the Zeeman deceleration light, and the proportion of low-speed atoms can be increased by applying transverse cooling laser, thereby achieving effective matching with the low-speed selector and significantly increasing the low-speed atomic flux of the atomic source. Figure 11 A represents the atomic velocity distribution of undecelerated hot atoms; B represents the atomic velocity distribution after applying -500MHz detuned Zeeman deceleration light; C represents the atomic velocity distribution after applying -450MHz detuned Zeeman deceleration light; and D represents the atomic velocity distribution after applying -450MHz detuned Zeeman deceleration light and -40MHz transverse cooling light.

[0055] In a further embodiment, the vacuum chamber is a cylindrical stainless steel or titanium alloy pipe, and its interior is under vacuum. The atomic furnace 1, Zeeman reducer 2, transverse cooler 3, low-speed selector 4, and thermal window 7 are respectively fixed inside the vacuum chamber, such as by bolts to the inner wall of the pipe, without direct contact between them. The side wall of the vacuum chamber is uniformly provided with multiple light-transmitting holes for the external light source transverse cooling laser 9 and speed-selective laser 5 to enter. Both ends of the vacuum chamber are provided with optical windows, through which the Zeeman decelerated light 6 enters from the other end in the opposite direction of atomic motion.

[0056] In this embodiment, the vacuum chamber is connected to an external vacuum pump to maintain the internal vacuum of the vacuum chamber at 5×10-9 mba.

[0057] In this embodiment, the atomic furnace 1 is a high-temperature atomic furnace with an operating temperature of 25℃-650℃ and a temperature fluctuation of less than 0.1℃. The furnace chamber of the high-temperature atomic furnace is equipped with three layers of heat shield, which are made of cylindrical non-magnetic stainless steel material with a certain thickness to prevent heat from dissipating, so that the temperature of the outer wall of the high-temperature atomic furnace is less than 60℃ when it is working at high temperature.

[0058] The transverse cooler 3 is located behind the Zeeman reducer 2 or is built into the interior of the Zeeman reducer 2; the outer wall of the transverse cooler 3 is provided with a laser inlet that communicates with its inner cavity; there are four laser inlets, which are respectively arranged in two orthogonal directions perpendicular to the direction of atomic beam motion.

[0059] In a further embodiment, a high-temperature resistant light-transmitting lens is embedded inside the heat window 7. The light-transmitting lens is made of sapphire or quartz material, and its operating temperature is 25℃-350℃ with a temperature fluctuation of less than 0.1℃.

[0060] The low-speed selector 4 is a two-dimensional magneto-optical trap, which is a device based on the principle of interaction between atoms and light. In this example, permanent magnets are arranged in a side-by-side array to form a gradient magnetic field of the two-dimensional magneto-optical trap with a zero magnetic field axis. The speed-selective laser 5 is incident perpendicular to the magnetic field axis to form a 2D MOT optical field, which causes the horizontally entering atomic beam to exit along the zero magnetic field axis under the action of the 2D MOT optical field.

[0061] In this application, the Zeeman reducer and low-speed selector are optional but not recommended to use a coil-type magnetic field design. Instead, a permanent magnet array design is adopted, which fundamentally solves the power consumption problem.

[0062] Multiple low-speed selectors 4 are provided and are arranged in a cascade manner. Each low-speed selector 4 is deflected by a certain angle, so that the zero magnetic field axis of the last low-speed selector 4 coincides with the axis of the vacuum differential tube 8.

[0063] In a further embodiment, the atomic beam is formed by heating and spraying alkali metal or alkaline earth metal solids in an atomic furnace 1. The alkali metal solids include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr), while the alkaline earth metal solids include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

[0064] Figure 4 , Figure 5 , Figure 6, Figure 7 Therefore 88 Taking Sr atoms as an example, we will illustrate the process of optimizing the optical parameters of each component. After the atomic source is connected to the experimental cavity, using... 88 The loading rate of the Sr blue magneto-optical trap (blue MOT) process is used to evaluate the parameter settings of the Zeeman decelerating beam, the transversely cooled laser, the rate-selective laser, and the furnace temperature setting (since the blue magneto-optical trap has a certain loading efficiency, the actual atomic beam current is greater than the loading rate of the blue MOT).

[0065] like Figure 4 As shown, in this example, the Zeeman-decelerated light achieves the optimal blue magneto-optical trap loading rate when the resonant frequency relative to the atom is set to -415MHz and the laser power to 40mW.

[0066] like Figure 5 As shown, the lateral cooling laser of the lateral cooler is optimally set at -22MHz (relative to the atomic resonance frequency) in this example, and only 4mW of laser is needed to save power.

[0067] like Figure 6 As shown, the speed-selective laser (two-dimensional magneto-optical trap) is optimally set at -18MHz (relative to the atomic resonance frequency) in this example, and the 2D MOT light provides more than 25mW of light.

[0068] like Figure 7 As shown, the atomic source output performance is compared at different furnace temperatures. It can be seen that the atomic source output flow rate increases with increasing furnace temperature, and the atomic flow rate reaches a peak of 2×10 at 580℃. 9 atoms / s.

[0069] Example 2:

[0070] A cold atom source experimental apparatus includes a cold atom source generating device and an experimental chamber as described in Example 1, wherein the outlet of the vacuum differential tube 8 in the cold atom source generating device is connected to the experimental chamber.

[0071] like Figure 3 As shown, multiple atomic source generating devices S1, S2, ..., Sn are generated at a certain angle θ. 12 θ 23 、…、θ in This combination is integrated into a multi-interface vacuum experimental chamber to realize a hybrid atomic source. For example, S1 can be used as... 88 Sr atom source generator, S2 can be used as 87 Sr atom source generator, S3 can be used as 86 Sr atom source generator, S1 can be used as 84The Sr atom source generator realizes a cold atom source generator for multiple Sr isotopes, which can be used in specific isotope mixed atom science experiments.

[0072] In addition, S1, S2, ..., Sn can be loaded with solids of different types of atoms to realize a cold atom source generating device for multi-atom mixed gas, which can be used in scientific experiments on mixed atomic gases.

[0073] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0074] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A high-current, low-speed selective cold atom source generator, comprising an atomic furnace (1), a Zeeman reducer (2), a transverse cooler (3), and a thermal window (7) arranged coaxially in sequence within a vacuum chamber, characterized in that, At least one low-speed selector (4) is provided between the transverse cooler (3) and the hot window (7). The low-speed selector (4) has a vacuum differential tube (8) in the direction of the zero magnetic field axis. The zero magnetic field axis of the low-speed selector (4) has an angle with the direction of the atomic beam movement from the atomic furnace (1). It also includes an optical unit, which guides the low-speed atomic beam to enter the vacuum differential tube (8) along the direction of the zero magnetic field axis of the low-speed selector (4). The optical unit includes a Zeeman decelerating beam (6), a transverse cooling laser (9), and a speed-selective laser (5); the Zeeman decelerating beam (6) and the atomic beam enter the Zeeman decelerator (2) in opposite directions and decelerate the atomic beam; the transverse cooling laser (9) enters the transverse cooler (3) to narrow the divergence angle of the atomic beam; the speed-selective laser (5) causes the low-speed atomic beam located in the low-speed selector (4) to move along the zero magnetic field axis of the low-speed selector (4) and enter the vacuum differential tube (8), and the on and off of the real-time atomic beam flow entering the vacuum differential tube (8) is controlled by controlling the on and off of the speed-selective laser (5); The low-speed selector (4) is a two-dimensional magneto-optical trap. Multiple low-speed selectors (4) are provided and arranged in a cascade manner. There is an angle between the zero magnetic field axis of each low-speed selector (4) and the direction of entry of the atomic beam, and the zero magnetic field axis of the last low-speed selector (4) coincides with the axis of the vacuum differential tube (8).

2. The cold atom source generating device according to claim 1, characterized in that, The vacuum chamber is a cylindrical stainless steel or titanium alloy pipe, and its interior is in a vacuum state; the atomic furnace (1), Zeeman reducer (2), transverse cooler (3), low speed selector (4) and hot window (7) are respectively fixed inside the vacuum chamber; The sidewall of the vacuum chamber is uniformly provided with multiple light-transmitting holes, and a vacuum window is installed on the light-transmitting hole to allow external light sources to enter; both ends of the vacuum chamber are provided with optical windows. The vacuum chamber is connected to an external vacuum pump, maintaining the internal vacuum of the vacuum chamber at 5 × 10⁻⁶. -9 mbar.

3. The cold atom source generating device according to claim 1, characterized in that, The atomic furnace (1) is a high-temperature atomic furnace with a working temperature of 25℃-650℃ and a temperature fluctuation of less than 0.1℃. The furnace chamber of the high-temperature atomic furnace is equipped with three layers of thermal shielding, so that the temperature of the outer wall of the high-temperature atomic furnace is less than 60℃ when it is working at high temperature.

4. The cold atom source generating device according to claim 1, characterized in that, The Zeeman reducer (2) is equipped with a permanent magnet array to form a Zeeman magnetic field, which causes the high-speed atomic beam generated by the atomic furnace (1) to be continuously decelerated to a low speed by the Zeeman decelerating light (6) moving in the opposite direction in the Zeeman magnetic field.

5. The cold atom source generating device according to claim 1, characterized in that, The transverse cooler (3) is located behind the Zeeman reducer (2) or is built into the interior of the Zeeman reducer (2); the outer wall of the transverse cooler (3) is provided with a laser inlet that communicates with its inner cavity; there are four laser inlets, which are respectively arranged in two orthogonal directions perpendicular to the direction of atomic beam motion.

6. The cold atom source generating apparatus according to claim 1, characterized in that, The heat window (7) is embedded with a high-temperature resistant light-transmitting lens. The light-transmitting lens is made of sapphire or quartz material and has a working temperature of 25℃-350℃ with a temperature fluctuation of less than 0.1℃. The atomic beam is formed by heating and spraying alkali metal or alkaline earth metal solids in an atomic furnace (1), wherein the alkali metal solids include lithium, sodium, potassium, rubidium, cesium and francium, and the alkaline earth metal solids include beryllium, magnesium, calcium, strontium, barium and radium.

7. A cold atom source experimental apparatus, characterized in that, It includes the cold atom source generating device and experimental chamber as described in claims 1-6, wherein the outlet of the vacuum differential tube (8) in the cold atom source generating device is connected to the experimental chamber.

8. The cold atom source experimental apparatus according to claim 7, characterized in that, The experimental chamber is provided with at least one interface, each interface being connected to the outlet of a vacuum differential tube (8) in one of the cold atom source generating devices; the types of atomic beams in each of the cold atom source generating devices may be the same or different.

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