Refrigerating system and ion trap system
Through the integrated wet and dry refrigeration system, liquid helium and high-pressure helium are used to jointly refrigerate, solving the problems of high liquid helium consumption and vibration impact, and achieving low-cost and efficient ion trap chip refrigeration.
Patent Information
- Application Number
- CN202410094560.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-22
- Publication Date
- 2025-07-22
AI Technical Summary
Existing wet refrigerators require a large amount of liquid helium when refrigerating ion trap chips, resulting in high operating costs and easy vaporization of liquid helium. The vibration of the dry refrigerator may affect the accuracy of the laser system.
Integrate wet and dry refrigeration systems to jointly refrigerate through liquid helium and high pressure helium, reduce liquid helium usage and optimize the refrigerator position to reduce cost and vibration impact.
With the same refrigeration power, significantly reduce liquid helium consumption, reduce operating costs, and reduce system errors caused by vibration, improving refrigeration efficiency and accuracy.
Smart Images
Figure CN120358702A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of quantum computing technology, and particularly to a refrigeration system and an ion trap system. Background Art
[0002] Ion trap chips have excellent quantum properties and have a large number of applications and broad prospects in many fields such as quantum computing, quantum simulation, and quantum precision measurement. Charged ions are trapped in the ion trap chip, and information is carried in the charged ions. By using laser irradiation on the charged ions, the charged ions can emit photons, thereby obtaining the information carried in the charged ions.
[0003] Arranging the ion trap chip in a low-temperature environment can significantly improve the working performance of the ion trap chip. Currently, a wet refrigeration machine can be used to refrigerate the ion trap chip. The technical principle of the wet refrigeration machine is to refrigerate the ion trap chip through liquid helium. Specifically, the wet refrigeration machine delivers liquid helium to the liquid helium cavity so that the liquid helium cavity refrigerates the ion trap chip through liquid helium.
[0004] The amount of liquid helium in the liquid helium cavity directly affects the refrigeration power of the wet refrigeration machine. If it is necessary to increase the refrigeration power for the ion trap chip, the amount of liquid helium in the liquid helium cavity needs to be increased. However, liquid helium has a low boiling point and is easily vaporized by heat, resulting in high operating costs. By increasing the amount of liquid helium in the liquid helium cavity to increase the refrigeration power, its operating costs will increase exponentially. Summary of the Invention
[0005] Embodiments of this application provide a refrigeration system and an ion trap system for integrating a dry refrigeration machine and a wet refrigeration machine to refrigerate a sample.
[0006] The first aspect of the present application provides a refrigeration system. In the present application, the refrigeration system includes a wet refrigeration system and a dry refrigeration system. The wet refrigeration system includes a wet refrigerator, a liquid helium cavity, a liquid helium pipeline, and a wet cold plate. The dry refrigeration system includes a dry refrigerator, a helium pipeline, and a first dry cold plate. The liquid helium pipeline is used to connect the wet refrigerator and the liquid helium cavity, and the helium pipeline is used to connect the dry refrigerator and the first dry cold plate. Among them, the wet refrigerator is used to transmit liquid helium to the liquid helium cavity through the liquid helium pipeline. Then, the liquid helium cavity can contact the wet cold plate and refrigerate the wet cold plate through the liquid helium. The dry refrigerator is used to transmit first high-pressure helium gas to the first dry cold plate through the helium pipeline. The first high-pressure helium gas is used to refrigerate the first dry cold plate, and the first dry cold plate can contact the sample and refrigerate the sample. The wet cold plate is used to contact the sample and refrigerate the sample. By integrating the wet refrigeration system and the dry refrigeration system into one refrigeration system, compared with using only the wet refrigeration system for refrigeration, when achieving the same refrigeration power, the amount of liquid helium consumed is greatly reduced, avoiding a geometric increase in operating costs, thereby reducing the operating cost of the refrigeration system.
[0007] In some possible implementation manners, the sample is in a columnar structure and is vertically placed; the wet cold plate is arranged above the sample, and the liquid helium cavity is arranged above the wet cold plate; the first dry cold plate is arranged below the sample.
[0008] Due to the fluid characteristics of liquid helium, when the liquid helium cavity refrigerates the wet cold plate through liquid helium, the bottom of the liquid helium cavity has a higher refrigeration power. Therefore, the wet cold plate is arranged above the ion trap chip, so that the liquid helium cavity can be arranged above the wet cold plate, and the liquid helium cavity refrigerates the wet cold plate with a higher refrigeration power, thereby improving the overall refrigeration power. Correspondingly, due to the gas characteristics of helium, the refrigeration power of the dry refrigerator is independent of the placement position. The first dry cold plate is placed around or below the ion trap chip in the horizontal direction, so that the dry refrigerator refrigerates the first dry cold plate from around or below in the horizontal direction.
[0009] In some possible implementations, the refrigeration system further includes a vacuum system for providing a vacuum environment for the ion trap chip. The vacuum system includes a vacuum housing, a vacuum flange, and a vacuum pump. The vacuum housing is a sealed hollow cavity. The internal space of the vacuum housing is used to accommodate the wet cold plate, the first dry cold plate, and the sample. The wet refrigerator and the dry refrigerator are respectively arranged in the external space of the vacuum housing. The vacuum pump is arranged on the vacuum housing and is used to evacuate the vacuum housing so that a vacuum environment is formed in the internal space of the vacuum housing. The vacuum flange is arranged on the vacuum housing and is used to provide an inlet and outlet for devices between the internal space and the external space of the vacuum housing so that a sample can be installed into the vacuum housing. The liquid helium pipeline penetrates the vacuum housing to connect the wet refrigerator and the wet cold plate. The helium pipeline penetrates the vacuum housing to connect the dry refrigerator and the first dry cold plate.
[0010] In some possible implementations, the refrigeration system further includes a thermal shielding system. The thermal shielding system is arranged in the internal space of the vacuum housing. The thermal shielding system includes a first thermal shielding layer. The first thermal shielding layer is a cylindrical structure and is arranged around the sample in the horizontal direction for shielding thermal radiation for the sample.
[0011] In some possible implementations, the thermal shielding system further includes a second thermal shielding layer. The second thermal shielding layer is a barrel-shaped structure with an opening facing the first dry cold plate. The second thermal shielding layer is arranged around and below the first dry cold plate for shielding thermal radiation for the first dry cold plate. The dry refrigeration system further includes a second dry cold plate. The helium pipeline is also used to connect the second dry cold plate. The second dry cold plate contacts the second thermal shielding layer and cools the second thermal shielding layer. The dry refrigerator is also used to transmit second high-pressure helium gas to the second dry cold plate through the helium pipeline.
[0012] It should be noted that the internal space formed by the second thermal shielding layer accommodates the first dry cold plate. The internal space formed by the second thermal shielding layer is the internal space of a hollow columnar structure formed if the barrel-shaped second thermal shielding layer is sealed. In some possible implementations, the material of the second thermal shielding layer can be copper or stainless steel, as long as it is a material that can achieve thermal shielding, and no limitation is made here.
[0013] In some possible implementation manners, the thermal shielding system further includes a third thermal shielding layer. The third thermal shielding layer is a barrel-shaped structure with an opening facing the wet cold plate. The third thermal shielding layer is disposed around and above the wet cold plate and is used to shield thermal radiation for the wet cold plate. The wet refrigeration system further includes a liquid nitrogen pipeline and a liquid nitrogen cavity. The liquid nitrogen pipeline penetrates through the vacuum housing and is used to connect the liquid nitrogen cavity and the wet refrigerator. The wet refrigerator is further used to transmit liquid nitrogen to the liquid nitrogen cavity through the liquid nitrogen pipeline. The liquid nitrogen cavity contacts the third thermal shielding layer and is used to cool the third thermal shielding layer with the liquid nitrogen.
[0014] In some possible implementation manners, the second thermal shielding layer and the third thermal shielding layer are connected by a thermal insulation connecting member. The thermal insulation connecting member is used to shield the first thermal shielding layer from the 300K (room temperature) thermal radiation from the vacuum housing and at the same time avoid heat transfer between the second thermal shielding layer and the third thermal shielding layer.
[0015] In some possible implementation manners, the material of the thermal insulation connecting member is constantan or polyether ether ketone (PEEK).
[0016] In some possible implementation manners, the diameter of the opening of the second thermal shielding layer is smaller than the diameter of the opening of the third thermal shielding layer, and a part of the opening of the second thermal shielding layer is embedded in the inner space of the third thermal shielding layer, and there is no contact between the second thermal shielding layer and the third thermal shielding layer; or, the diameter of the opening of the third thermal shielding layer is smaller than the diameter of the opening of the second thermal shielding layer, and a part of the opening of the third thermal shielding layer is embedded in the inner space of the second thermal shielding layer, and there is no contact between the third thermal shielding layer and the second thermal shielding layer. Thereby, thermal isolation between the third thermal shielding layer and the second thermal shielding layer is achieved. At the same time, the thermal shielding functions of the third thermal shielding layer and the second thermal shielding layer can be realized, and the 300K thermal radiation from the vacuum housing is also shielded for the first thermal shielding layer.
[0017] The second aspect of the present application provides an ion trap system, including: an ion trap chip, a fluorescence detection device, a laser system, and the refrigeration system as described above. The sample is the ion trap chip. The laser system is used to send laser to the ion trap chip. The fluorescence detection device is used to receive photons emitted by the ion trap chip.
[0018] In the embodiment of the present application, by integrating the wet refrigeration system and the dry refrigeration system into one refrigeration system, compared with only using the wet refrigeration system for refrigeration, when achieving the same refrigeration power, the amount of liquid helium consumed is greatly reduced, avoiding a geometric multiple increase in the operating cost, thereby reducing the operating cost of the refrigeration system.
[0019] In addition, the mechanical device in the dry chiller generates vibrations during operation. When the refrigeration power of the dry chiller is increased, greater vibrations (generally in the micron range) will be caused. When the vibrations reach a certain level, the vibrations will be transmitted to the ion trap chip, causing a relative displacement between the irradiation direction of the laser system and the position of the charged ions, resulting in a large system error. Therefore, compared with using only a wet cold plate for refrigeration, the technical solution of this application causes less vibration when achieving the same refrigeration power, avoiding the relative displacement between the irradiation direction of the laser system and the charged ions in the ion trap chip, thereby avoiding a large system error.
[0020] In some possible implementation manners, the fluorescence detection device includes an objective lens and a camera; the objective lens is used to refract the photons emitted by the ion trap chip to the camera; the camera is used to receive the photons refracted by the objective lens and convert them into electrical signals; wherein, the camera is arranged in the external space of the vacuum housing, the vacuum housing further includes a light passing window, the passing window is made of a light-transmitting material, and the camera, the light passing window and the ion trap chip are on a straight line, so that the photons emitted by the ion trap chip pass through the light passing window and are received by the camera.
[0021] In some possible implementation manners, the light passing window is a concave structure on the vacuum housing; the objective lens is arranged in the external space of the vacuum housing and is adjacent to the light passing window, so that the distance between the objective lens and the ion trap chip is not greater than the working distance of the objective lens.
[0022] In some possible implementation manners, the contact surface between the wet cold plate and the ion trap chip forms a first angle with the horizontal plane, and the contact surface between the first dry cold plate and the ion trap chip forms a second angle with the horizontal plane. The directions of the first angle and the second angle are opposite, so that the wet cold plate and the first dry cold plate form a wedge-shaped structure, and the wedge-shaped structure is used to fix the position of the ion trap chip.
[0023] In some possible implementation manners, the ion trap system further includes:
[0024] The first adjusting piece and / or the second adjusting piece; the first adjusting piece is arranged above the wet cold plate to adjust the position of the wet cold plate in the vertical direction; the second adjusting piece is arranged below the first dry cold plate to adjust the position of the first dry cold plate in the vertical direction. By increasing or decreasing the adjusting piece, the distance between the first dry cold plate and the wet cold plate is made smaller, so that the ion trap chip moves to the right to offset the displacement change caused by X (the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240 is longer than the length of the ion trap chip 110 by X).
[0025] In some possible implementation manners, the objective lens is arranged in the internal space of the vacuum housing so that the distance between the objective lens and the ion trap chip is not greater than the working distance of the objective lens. Description of the Drawings
[0026] Figure 1-1 Schematic diagram of a system architecture provided by an embodiment of the present application;
[0027] Figure 1-2 Schematic diagram of the working process of the control system provided by an embodiment of the present application;
[0028] Figure 2 Schematic diagram of a refrigeration system provided by an embodiment of the present application;
[0029] Figure 3 Another schematic diagram of a refrigeration system provided by an embodiment of the present application;
[0030] Figure 4 Another schematic diagram of a refrigeration system provided by an embodiment of the present application;
[0031] Figure 5 Another schematic diagram of a refrigeration system provided by an embodiment of the present application;
[0032] Figure 6 Another schematic diagram of a refrigeration system provided by an embodiment of the present application;
[0033] Figure 7 Distribution diagram of the temperatures of the vacuum housing and the thermal shielding system provided by an embodiment of the present application;
[0034] Figure 8 Distribution diagram of the thermal radiation received by the vacuum housing and the thermal shielding system provided by an embodiment of the present application;
[0035] Figure 9 Schematic diagram of the relationship between the thermal radiation received by the outer surface of the first thermal shielding layer and L provided by an embodiment of the present application;
[0036] Figure 10Schematic diagram of an ion trap system provided by an embodiment of the present application;
[0037] Figure 11 Schematic diagram of a fluorescence detection device provided by an embodiment of the present application;
[0038] Figure 12 Another schematic diagram of a fluorescence detection device provided by an embodiment of the present application;
[0039] Figure 13 Schematic diagram of a wedge-shaped structure formed by a wet cold plate and a first dry cold plate provided by an embodiment of the present application;
[0040] Figure 14 Another schematic diagram of a wedge-shaped structure formed by a wet cold plate and a first dry cold plate provided by an embodiment of the present application;
[0041] Figure 15 Another schematic diagram of a wedge-shaped structure formed by a wet cold plate and a first dry cold plate provided by an embodiment of the present application;
[0042] Figure 16 Schematic diagram of a laser system provided by an embodiment of the present application;
[0043] Figure 17 Schematic diagram of an ion trap chip receiving laser light in multiple directions provided by an embodiment of the present application. Detailed implementation manners
[0044] An embodiment of the present application provides an ion trap system for integrating a dry refrigerator and a wet refrigerator to cool a sample.
[0045] The embodiments of the present application will be described below with reference to the accompanying drawings.
[0046] Terms such as "first" and "second" in the specification, claims and above-mentioned drawings of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing objects with the same attributes when describing embodiments of the present application. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, so that a process, method, system, product or device including a series of units does not have to be limited to those units, but may include other units not clearly listed or inherent to these processes, methods, products or devices.
[0047] As Figure 1-1 shown, the system architecture applied in the embodiments of the present application includes: an ion trap chip 110, a refrigeration system 120, a voltage source 140, a laser system 150, a fluorescence detection device 160, and a control system 170.
[0048] Among them, the ion trap chip 110 includes a plurality of electrodes. By applying voltages to the plurality of electrodes of the ion trap chip 110, an electric potential field can be formed in the space inside the ion trap chip 110, and this electric potential field can trap charged ions in the ion trap chip 110. Exemplarily, the charged ions can be calcium ions (Ca+) or strontium ions (Sr+), which are not limited herein.
[0049] The charged ions can be used to store information. For example, the information can be 1 or 0. Exemplarily, the charged ions have an ion state, and the ion state can be the 1 state or the 0 state. Among them, the 1 state is used to represent 1, and the 0 state is used to represent 0. When an energy pulse is applied to the charged ions, the ion state of the charged ions can be changed, for example, from the 0 state to the 1 state, or from the 1 state to the 0 state. When the charged ions are irradiated by a laser, the charged ions with the ion state of 1 can be excited. Then, if the ion state of the charged ions is the 1 state, the charged ions will emit photons under the excitation of the laser. After the photons are received, it can be determined that the ion state of the charged ions is the 1 state, and the obtained information is 1. If the ion state of the charged ions is the 0 state, the charged ions will not emit photons under the excitation of the laser. Since no photons are received, it is determined that the ion state of the charged ions is the 0 state, and the obtained information is 0.
[0050] Among them, the laser system 150 is used to emit a laser to the charged ions in the ion trap chip 110. The fluorescence detection device 160 is used to receive the photons emitted by the charged ions in the ion trap chip 110, so as to obtain the information stored by the charged ions. It should be noted that the ion trap chip 110, the laser system 150, and the fluorescence detection device 160 can be fixedly placed on an optical table respectively, so that the laser irradiation direction of the laser system 150 can be aligned with the ion trap chip 110, and the fluorescence detection device 160 is placed in the emission direction of the photons of the ion trap chip 110.
[0051] Arranging the ion trap chip in a low-temperature environment can significantly improve the working performance of the ion trap chip. Therefore, a low-temperature environment needs to be provided for the ion trap chip 110. In order to prevent the charged ions in the ion trap chip 110 from being interfered by air, a vacuum environment also needs to be provided for the ion trap chip 110. In the embodiment of the present application, the refrigeration system 120 can provide a low-temperature environment and a vacuum environment for the ion trap chip 110.
[0052] The voltage source 140 can be connected to the plurality of electrodes of the ion trap chip 110 and supply power to the plurality of electrodes, so as to apply voltages to the plurality of electrodes of the ion trap chip 110. In some possible implementation manners, the voltage source 140 can be connected to the mains power or a mobile power source, which is not limited herein.
[0053] The control system 170 is used to connect the laser system 150, the fluorescence detection device 160, and the voltage source 140. The control system 170 can provide an operation interface through which the user can operate the control system 170 to control the laser system 150, the fluorescence detection device 160, and the voltage source 140, so as to realize the trapping of charged ions in the ion trap chip 110 by controlling the voltage source 140, emit laser to the ion trap chip 110 by controlling the laser system 150, and obtain the photons emitted by the ion trap chip 110 by controlling the fluorescence detection device 160.
[0054] Exemplarily, as Figure 1-2 shown, by operating the control system 170, the environment where the ion trap chip 110 is located can be evacuated first, and the vacuum environment can be maintained by the vacuum system 130. Then, the ion trap chip 110 can be cooled by the cooling system 120 to obtain a low-temperature environment. Next, the atoms in the ion trap chip 110 can be ionized by the laser system 150 and the fluorescence detection device 160 to obtain charged ions, and functions such as initial state preparation, related operations, and state detection can be realized for the charged ions.
[0055] Currently, the cooling system 130 can be a wet cooling system or a dry cooling system.
[0056] Among them, the technical principle of the wet cooling system is to cool the ion trap chip 110 with liquid helium. Exemplarily, the wet cooling system includes a wet refrigerator, a liquid helium cavity, and a wet cold plate. The wet refrigerator is used to transport liquid helium to the liquid helium cavity so that the liquid helium cavity cools the wet cold plate through the liquid helium, and the wet cold plate then cools the ion trap chip. The amount of liquid helium in the liquid helium cavity directly affects the cooling power of the wet refrigerator. If it is necessary to increase the cooling power of the ion trap chip, the amount of liquid helium in the liquid helium cavity needs to be increased. However, liquid helium has a low boiling point and is easily vaporized by heat, resulting in high operating costs. By increasing the amount of liquid helium in the liquid helium cavity to increase the cooling power, its operating costs will increase exponentially.
[0057] The technical principle of the dry cooling system is to cool the ion trap chip 110 by forming high-pressure helium gas through a mechanical device. Exemplarily, the dry cooling system includes a dry refrigerator and a dry cold plate. Among them, the dry refrigerator is used to form high-pressure helium gas, and the high-pressure helium gas is used to cool the dry cold plate. The dry cold plate contacts the ion trap chip 110 to cool the ion trap chip 110.
[0058] Therefore, the present application proposes a cooling system for simultaneously using a dry refrigerator and a wet refrigerator for cooling.
[0059] In the present application, as Figure 2As shown, the refrigeration system 120 includes a wet refrigeration system 200 and a dry refrigeration system 300. Among them, the wet refrigeration system 200 includes a wet refrigerator 210, a liquid helium pipeline 220, a liquid helium cavity 230, and a wet cold plate 240. The dry refrigeration system 300 includes a dry refrigerator 310, a helium pipeline 320, and a first dry cold plate 330. The wet refrigerator 210 is used to transmit liquid helium to the liquid helium cavity 230 through the liquid helium pipeline 220. The liquid helium cavity 230 is used to contact the wet cold plate 240 and refrigerate the wet cold plate 240 with the liquid helium. The dry refrigerator 310 is used to transmit first high-pressure helium gas to the first dry cold plate through the helium pipeline 320. The first high-pressure helium gas is used to refrigerate the first dry cold plate. The first dry cold plate is used to contact the sample and refrigerate the sample. The wet cold plate is used to contact the sample and refrigerate the sample.
[0060] By integrating the wet refrigeration system 200 and the dry refrigeration system 300 into one refrigeration system, compared with using only the wet refrigeration system 200 for refrigeration, when achieving the same refrigeration power, the amount of liquid helium consumed is greatly reduced, avoiding a geometric increase in operating costs, thereby reducing the operating cost of the refrigeration system 120.
[0061] In some possible implementation manners, the housing material of the sample can be copper or stainless steel, as long as it is a heat-conducting material, which is not limited herein. In some possible implementation manners, the sample can be an ion trap chip or a Rydberg atom device, which is not limited herein.
[0062] Since the boiling point of liquid helium under normal pressure is 4.2 kelvins (K), in the wet refrigeration system 200, the liquid helium in the liquid helium cavity 230 can reach 4.2K or below. Then, the liquid helium cavity 230 can reduce the temperature of the wet cold plate 240 to 4.2K or below through the liquid helium, and then the wet cold plate 240 can also reduce the temperature of the sample to 4.2K or below.
[0063] The dry refrigerator 310 (such as a Gifford McMahon (G-M) refrigerator) is internally provided with a mechanical device (such as a compressor) for converting liquid helium into first high-pressure helium gas and transmitting the first high-pressure helium gas to the first dry cold plate 330. Among them, the boiling point of helium under high-pressure conditions can be less than 4.2K. Therefore, under the action of the first high-pressure helium gas, the temperature of the first dry cold plate 330 can reach 4.2K or below. Then, the first dry cold plate 330 can reduce the temperature of the sample to 4.2K or below.
[0064] In the embodiment of the present application, as Figure 2As shown, the sample is in contact with the wet cold plate 240 and the first dry cold plate 330 respectively, so that the wet cold plate 240 and the first dry cold plate 330 cool the sample simultaneously. Compared with only using the wet cold plate 240 for cooling, when achieving the same cooling power, the amount of liquid helium consumed is greatly reduced, thus greatly reducing the operating cost.
[0065] In some possible implementation manners, the wet cold plate 240 and the first dry cold plate 330 can be arranged on the corresponding two sides of the sample, such as the upper and lower sides or the left and right sides. In some possible implementation manners, the wet cold plate 240 and the first dry cold plate 330 can also be arranged on the non-corresponding two sides of the sample, such as the upper side and the left side, as long as the wet cold plate 240 and the first dry cold plate 330 can both contact the sample and cool the sample, and there is no limitation here.
[0066] Exemplarily, as Figure 2 shown, the sample is in a columnar structure and is placed vertically, such as a cylinder, a cuboid or a polygonal column, and there is no limitation here. The wet cold plate 240 and the first dry cold plate 330 are both disks and are placed horizontally. The wet cold plate 240 is placed above the sample, and the first dry cold plate 330 is placed below the sample. In some possible implementation manners, the wet cold plate 240 can also be placed below the sample, and the first dry cold plate 330 can be placed above the sample, and there is no limitation here.
[0067] Due to the fluid characteristics of liquid helium, when the liquid helium in the liquid helium cavity 230 cools the wet cold plate 240, the bottom of the liquid helium cavity 230 has a higher cooling power. Therefore, preferably, the wet cold plate 240 can be arranged above the ion trap chip 110, so that the liquid helium cavity 230 can be arranged above the wet cold plate 240, so that the liquid helium cavity 230 cools the wet cold plate 240 with a higher cooling power, thereby improving the overall cooling power. Correspondingly, due to the gas characteristics of helium, the cooling power of the dry cooler 310 is independent of the placement position, so the first dry cold plate 330 can be placed around or below the ion trap chip 110 in the horizontal direction, so that the dry cooler 310 cools the first dry cold plate 330 from around or below in the horizontal direction.
[0068] In the following description of the embodiments of the present application, the example of arranging the wet cold plate 240 above the ion trap chip 110 and placing the first dry cold plate 330 below the ion trap chip 110 is taken for illustration.
[0069] In some possible implementation manners, since the wet cooler 210 is connected to the liquid helium cavity 230 through the liquid helium pipeline 220, in order to maximize the cooling power, the liquid helium pipeline 220 should be made the shortest, as Figure 2As shown, the wet chiller 210 can be arranged above the liquid helium cavity 230. Correspondingly, since the dry chiller 310 is connected to the first dry cold plate 330 through the helium gas pipeline 320, in order to maximize the refrigeration power, the helium gas pipeline 320 should be made as short as possible, as Figure 2 shown, the dry chiller 310 can be arranged below the first dry cold plate 330.
[0070] In some possible implementation manners, the wet chiller 210 and the dry chiller 310 can also be arranged at other positions based on requirements, which are not limited herein. For example, the wet chiller 210 is arranged above the liquid helium cavity 230, and the dry chiller 310 is arranged in the horizontal direction of the dry chiller 310. This is not limited herein.
[0071] In the following description of the embodiments of the present application, the example in which the wet chiller 210 is arranged above the liquid helium cavity 230 and the dry chiller 310 is arranged below the dry chiller 310 is used for illustration.
[0072] In some possible implementation manners, as Figure 3 shown, the refrigeration system 120 further includes a vacuum system 130, and the vacuum system 130 may include a vacuum housing 131, a vacuum pump 132, and a vacuum flange 133 (for example, a vacuum flange of model CF150).
[0073] The vacuum housing 131 is a sealed hollow cavity, and the internal space of the vacuum housing 131 is used to accommodate the wet cold plate 240, the first dry cold plate 330, and the sample. Among them, the wet chiller 210 and the dry chiller 310 are respectively arranged in the external space of the vacuum housing 131. The vacuum pump 132 is arranged on the vacuum housing 131 and is used to evacuate the vacuum housing 131 so that the internal space of the vacuum housing 131 forms a vacuum environment. The vacuum flange 133 is arranged on the vacuum housing 131 and is used to provide an inlet and outlet for devices between the internal space and the external space of the vacuum housing 131. For example, through the vacuum flange 133, a sample can be installed inside the vacuum housing 131.
[0074] In some possible implementation manners, both the wet chiller 210 and the dry chiller 310 are arranged outside the vacuum housing 131, while the liquid helium cavity 230, the wet cold plate 240, and the first dry cold plate 330 are all arranged inside the vacuum housing 131. For this reason, the liquid helium pipeline 220 can penetrate the vacuum housing 131 to connect the wet chiller 210 and the wet cold plate 240; the helium gas pipeline 320 can penetrate the vacuum housing 131 to connect the dry chiller 310 and the first dry cold plate 330.
[0075] In an embodiment of the present application, in order to shield the thermal radiation of an external heat source (such as infrared rays emitted by a human body), a thermal shielding system may be provided around the sample. The thermal shielding system includes a plurality of thermal shielding layers, and among them, the plurality of thermal shielding layers are all arranged in the internal space of the vacuum housing 131.
[0076] In some possible implementation manners, as Figure 4 shown, the thermal shielding system includes a first thermal shielding layer 410. The first thermal shielding layer 410 is a cylindrical structure and is arranged around the sample in the horizontal direction, and is used to shield the thermal radiation for the sample.
[0077] In some possible implementation manners, the first thermal shielding layer 410 is respectively connected to the wet cold plate 240 and the first dry cold plate 330. The material of the first thermal shielding layer 410 may be a material that can achieve thermal shielding such as copper or stainless steel, and is not limited herein. Since the material of the T0 thermal shielding is a heat-conducting material, when the first thermal shielding layer 410 contacts the wet cold plate 240 and the first dry cold plate 330, the wet cold plate 240 and the first dry cold plate 330 can respectively cool the T0 thermal shielding, so that the temperature of the first thermal shielding layer 410 is consistent with that of the wet cold plate 240 and the first dry cold plate 330, that is, a temperature of 4.2K or below.
[0078] In some possible implementation manners, as Figure 5 shown, the thermal shielding system further includes a second thermal shielding layer 420. The second thermal shielding layer 420 is a barrel-shaped structure with an opening facing the first dry cold plate 330. The second thermal shielding layer 420 is arranged around and below the first dry cold plate 330, and is used to shield the thermal radiation for the first dry cold plate 330.
[0079] It should be noted that the internal space formed by the second thermal shielding layer 420 houses the first dry cold plate 330. The internal space formed by the second thermal shielding layer 420 is the internal space of a hollow columnar structure formed if the barrel-shaped second thermal shielding layer 420 is sealed. In some possible implementation manners, the material of the second thermal shielding layer 420 may be copper or stainless steel, as long as it is a material that can achieve thermal shielding, and is not limited herein.
[0080] In some possible implementations, the dry refrigeration system 300 may further include a second dry cold plate 340. The second dry cold plate 340 is connected to the dry refrigerator 310 through the helium gas pipeline 320, and the second dry cold plate 340 contacts the second thermal shielding layer 420. The dry refrigerator 310 converts helium gas into second high-pressure helium gas and transmits the second high-pressure helium gas to the second dry cold plate 340 through the helium gas pipeline 320, so as to refrigerate the second dry cold plate 340, so that the second dry cold plate 340 can refrigerate the second thermal shielding layer 420. Exemplarily, the temperature of the second dry cold plate 340 can be set as needed by the dry refrigerator 310, such as 40K, 44K, 77K, etc. In the embodiment of the present application, the temperature of the second dry cold plate 340 is taken as an example of 40K for illustration.
[0081] In some possible implementations, as Figure 5 shown, the thermal shielding system further includes a third thermal shielding layer 430. The third thermal shielding layer 430 is a barrel-shaped structure with an opening facing the wet cold plate 240. The third thermal shielding layer 430 is arranged around and above the wet cold plate 240 for shielding thermal radiation for the wet cold plate 240.
[0082] In some possible implementations, the internal space formed by the third thermal shielding layer 430 houses the wet cold plate 240 and the liquid helium cavity 230. In some possible implementations, the material of the third thermal shielding layer 430 can be copper or stainless steel, as long as it is a material that can achieve thermal shielding, which is not limited here.
[0083] In some possible implementations, as Figure 5 shown, the wet refrigeration system 200 further includes a liquid nitrogen pipeline 260 and a liquid nitrogen cavity 250. The liquid nitrogen pipeline 260 penetrates the vacuum housing 131 for connecting the liquid nitrogen cavity 250 and the wet refrigerator 210. Wherein, the wet refrigerator 210 is further used to transmit liquid nitrogen to the liquid nitrogen cavity 250 through the liquid nitrogen pipeline 260. The liquid nitrogen cavity 250 contacts the third thermal shielding layer 430 and is used to refrigerate the third thermal shielding layer 430 with liquid nitrogen. It should be noted that since the boiling point of liquid nitrogen is 77K, then, the temperature of the third thermal shielding layer 430 can be set below 77K as needed through the liquid nitrogen cavity 250, such as 40K, 44K, 77K, etc. In the embodiment of the present application, the temperature of the third thermal shielding layer 430 is taken as an example of 77K for illustration.
[0084] In some possible implementations, to prevent the first thermal shield layer 410 from being exposed to the 300K (room temperature) thermal radiation from the vacuum housing 131, a connecting member can be disposed between the second thermal shield layer 420 and the third thermal shield layer 430. This connecting member is used to connect the second thermal shield layer 420 and the third thermal shield layer 430 and shield the first thermal shield layer 410 from the 300K (room temperature) thermal radiation from the vacuum housing 131. However, since there may be a temperature difference between the second thermal shield layer 420 and the third thermal shield layer 430, the connecting member can be thermally insulating, i.e., the thermally insulating connecting member 440.
[0085] Therefore, in some possible implementations, as Figure 5 shown, the thermal shield system can include a thermally insulating connecting member 440. The thermally insulating connecting member 440 is used to connect the second thermal shield layer 420 and the third thermal shield layer 430, shield the first thermal shield layer 410 from the 300K (room temperature) thermal radiation from the vacuum housing 131, and at the same time prevent heat transfer between the second thermal shield layer 420 and the third thermal shield layer 430.
[0086] In some possible implementations, for the selection of the material of the thermally insulating connecting member 440, the heat conduction formula can be considered:
[0087]
[0088] where is the heat load (in watts (W)), k is the heat conduction coefficient, A is the cross-sectional area representing heat transfer, l is the heat conduction distance, and T represents temperature. Exemplarily, assuming that the thermally insulating connecting member 440 is a cylindrical structure, the value of A is 10 -3 m 2 (square meters), the value of l is 0.1 m (meters), T2 is the temperature of the third thermal shield layer 430 (e.g., 77K), and T1 is the temperature of the second thermal shield layer 420 (e.g., 40K).
[0089] It should be noted that on the one hand, the second thermal shield layer 420 is cooled by the second dry cold plate 340 (to 40K), and on the other hand, the second thermal shield layer 420 also receives the temperature (77K) from the third thermal shield layer 430 through the thermally insulating connecting member 440. If the second thermal shield layer 420 is to maintain 40K, the heat load transferred from the third thermal shield layer 430 to the second thermal shield layer 420 should be much less than the refrigeration power of the second dry cold plate 340. For example, the refrigeration power of the second dry cold plate 340 is 10 watts (W), and the heat load requirement transferred from the third thermal shield layer 430 to the second thermal shield layer 420 is 1W or less (much less than 10W), i.e., Then, based on the above formula, it can be obtained that:
[0090]
[0091] k < 1 W / (10 -3 m 2 / 0.1 m) / (77 K - 40 K)
[0092] k < 100 W / m / 37 K
[0093] k < 2.702 W / m / K
[0094] Thus, when k < 2.702 (W / m / K), it can be obtained that the temperature of the third thermal shield layer 430 will not affect the temperature of the second thermal shield layer 420, and the third thermal shield layer 430 and the second thermal shield layer 420 can each maintain their original set temperatures. Then, materials that can be selected include constantan or polyether ether ketone (PEEK), etc., which are not limited herein.
[0095] In some possible implementation manners, the thermal insulation connecting member 440 may not be used between the third thermal shield layer 430 and the second thermal shield layer 420. Instead, in a nested manner, there is a certain overlap between the internal space formed by the second thermal shield layer 420 and the internal space formed by the third thermal shield layer 430, and the region within the second thermal shield layer 420 and the third thermal shield layer 430 can be made not to contact.
[0096] Exemplarily, as Figure 6 shown, both the second thermal shield layer 420 and the third thermal shield layer 430 are barrel-shaped structures, and the openings of both the second thermal shield layer 420 and the third thermal shield layer 430 are circular. The diameter of the opening of the second thermal shield layer 420 can be designed to be smaller than the diameter of the opening of the third thermal shield layer 430. Then, the second thermal shield layer 420 can be inserted into the opening of the third thermal shield layer 430 from the opening, so that a part of the second thermal shield layer 420 is accommodated in the internal space of the third thermal shield layer 430, and the third thermal shield layer 430 and the second thermal shield layer 420 do not contact, achieving thermal isolation between the third thermal shield layer 430 and the second thermal shield layer 420. At the same time, the thermal shielding functions of the third thermal shield layer 430 and the second thermal shield layer 420 can be realized, and the first thermal shield layer 410 is also shielded from the 300 K thermal radiation from the vacuum housing 131.
[0097] In some possible implementations, if the sample is the ion trap chip 110, since the photons emitted by the ion trap chip 110 need to exit through the light-transmitting window, then a light-transmitting window needs to be provided on the second thermal shielding layer 420 and / or the third thermal shielding layer 430. If light-transmitting windows need to be provided on both the second thermal shielding layer 420 and the third thermal shielding layer 430, the light-transmitting window on the second thermal shielding layer 420 and the light-transmitting window on the third thermal shielding layer 430 need to be aligned.
[0098] It should be noted that the size of the light-transmitting window cannot be smaller than the required minimum size, and this minimum size is determined by the numerical aperture (NA) of the objective lens 161 of the fluorescence detection device 160. Being smaller than this value will affect the photon collection efficiency. At the same time, the size of the light-transmitting window should be as small as possible, otherwise more thermal radiation of 300K from the vacuum housing 131 will enter the space inside the first thermal shielding layer 410 through this light-transmitting window, thus affecting the ion trap chip 110. Therefore, the size of the light-transmitting window can be designed to be slightly larger than the required minimum size.
[0099] As Figure 6 shown, the length of the second thermal shielding layer 420 embedded in the third thermal shielding layer 430 is set as L. In some possible implementations, L can also be set to 0, in which case there is no need to align the light-transmitting window on the second thermal shielding layer 420 and the light-transmitting window on the third thermal shielding layer 430.
[0100] In the case of performing the following settings, the thermal radiation received by each thermal shielding layer in the thermal shielding system can be simulated by a computer: the external temperature of the vacuum housing 131 is set to 300K (room temperature), the temperature of the second thermal shielding layer 420 is 40K, the temperature of the third thermal shielding layer 430 is 77K, the temperature of the T0 thermal shielding is 4K, the material is set to copper, the surface emissivity is 0.1, and L = 0. Then, the temperature distributions of the first thermal shielding layer 410, the second thermal shielding layer 420, and the third thermal shielding layer 430 can be obtained through computer simulation. As Figure 7 shown, that is, the temperature of the first thermal shielding layer 410 is 4.2K, the temperature of the second thermal shielding layer 420 is 40K, and the temperature of the third thermal shielding layer 430 is 77K; the surface radiation distributions received by the first thermal shielding layer 410, the second thermal shielding layer 420, the third thermal shielding layer 430, and the vacuum housing 131 respectively are as Figure 8 shown.
[0101] It should be noted that L will affect the thermal radiation received by the first thermal shielding layer 310. As Figure 9 shown, the relationship between the thermal radiation received by the outer surface of the first thermal shielding layer 310 and L can be obtained through computer simulation. Among them, the vertical axis represents the amount of thermal radiation, denoted by Q, with the unit of joule, and the horizontal axis is the value of L. AsFigure 9 As shown, among the various values of L (-0.1, -0.05, 0, 0.05, 0.1, 0.15, 0.2, 0.25), when L = -0.05 (m), the amount of thermal radiation directly received by the outer surface of the first thermal shielding layer 410 (the larger the absolute value, the greater the amount of thermal radiation received) is the largest, approaching -2.5. When L gradually increases, the thermal radiation received by the outer surface of the first thermal shielding layer 410 gradually decreases. Thus, in this simulation case, it can be set that L > 0.05 (m) to control the thermal radiation at a relatively low level.
[0102] As Figure 10 As shown, the present application proposes an ion trap system 1000, which includes the ion trap chip 110, the fluorescence detection device 160, the laser system 150, and the refrigeration system 120 as described above, where the sample is the ion trap chip 110. Among them, the laser system 150 is used to send laser to the ion trap chip 110, and the fluorescence detection device 160 is used to receive photons emitted by the ion trap chip 160.
[0103] In the embodiment of the present application, by integrating the wet refrigeration system 200 and the dry refrigeration system 300 into one refrigeration system, compared with using only the wet refrigeration system 200 for refrigeration, when achieving the same refrigeration power, the amount of liquid helium consumed is greatly reduced, avoiding the geometric increase in operating costs, thereby reducing the operating cost of the refrigeration system 120.
[0104] In addition, the mechanical device in the dry refrigerator generates vibrations during operation. When the refrigeration power of the dry refrigerator is increased, greater vibrations (generally in the micron range) will be caused. When the vibrations reach a certain level, the vibrations will be transmitted to the ion trap chip 110, causing a relative displacement between the irradiation direction of the laser system and the position of the charged ions, resulting in a large system error. Therefore, compared with using only the wet cold plate 240 for refrigeration, in the technical solution of the present application, when achieving the same refrigeration power, the vibrations caused by the technical solution of the present application are smaller, avoiding the relative displacement between the irradiation direction of the laser system 150 and the position of the charged ions in the ion trap chip 110, thereby avoiding the occurrence of a large system error.
[0105] In the embodiment of the present application, light passing windows are provided on the first thermal shielding layer 410, the second thermal shielding layer 420, the third thermal shielding layer 430, and the vacuum housing 131 between the laser system 150 and the ion trap chip 110, and between the fluorescence detection device 160 and the ion trap chip 110. It should be noted that the light passing window can be a light-transmitting material (such as glass), which is not limited here.
[0106] Exemplarily, as Figure 11The top view shown has the vertical direction as the z - direction, and the two mutually perpendicular horizontal directions are the x - direction and the y - direction. Among them, the direction from the fluorescence detection device 160 towards the ion trap chip 110 is the y - direction, and the direction perpendicular to the y - direction and the z - direction is the x - direction.
[0107] It should be noted that the ion trap chip 110 is vertically placed, and multiple charged ions in the ion trap chip 110 can be placed along the vertical direction, that is, along the z - direction. The photons emitted by the charged ions in the ion trap chip 110 are emitted in the opposite direction of the y - direction, and the fluorescence detection device 160 can receive the photons. The fluorescence detection device 160 is arranged outside the vacuum housing 131, and the photons can pass through the light - passing window on the vacuum housing 131 and reach the fluorescence detection device 160 so that the fluorescence detection device 160 can acquire the photons.
[0108] As Figure 11 shown, the fluorescence detection device 160 includes an objective lens 161 and a camera 162. Among them, the objective lens 161 is used to refract the photons emitted by the ion trap chip to the camera, and the camera 162 is used to receive the photons refracted by the objective lens 161 and convert them into electrical signals. It should be noted that the camera 162, the light - passing window, and the ion trap chip 110 are on a straight line so that the photons emitted by the ion trap chip 110 pass through the light - passing window and are received by the camera 162.
[0109] It should be noted that in order to ensure the photon collection efficiency, the numerical aperture (NA) of the objective lens 161 usually needs to be greater than 0.4. Based on the value of NA, it is required that the working distance of the objective lens 161 is less than dozens of millimeters. To meet this requirement, the light - passing window of the vacuum housing 131 can be designed as a concave structure, or the objective lens 161 can be placed inside the vacuum housing 131.
[0110] It should be noted that as Figure 12 shown, the light - passing window is a concave structure on the vacuum housing 131. The objective lens 161 is arranged in the external space of the vacuum housing 131, and the objective lens 161 is adjacent to the light - passing window, and the distance between the objective lens 161 and the ion trap chip 110 is not greater than the working distance of the objective lens 161. It should be noted that the light - passing window is between the objective lens 161 and the ion trap chip 110. When the charged ions in the ion trap chip 110 emit photons, the photons first reach the light - passing window and then reach the objective lens 161, and then the objective lens 161 can refract the photons to the camera 162.
[0111] Exemplarily, if the light-transmitting window of the vacuum housing 131 is a standard CF63 window (i.e., a window with a diameter of 63 mm), since the boundary of the standard CF63 window is usually not available for use, the maximum diameter of the objective lens 161 is approximately 55 mm. If the working distance of the objective lens 161 is required to be 30 mm or less, since the light-transmitting window is between the objective lens 161 and the ion trap chip 110, the distance from the light-transmitting window to the ion trap chip 110 should be less than 30 mm. Additionally, the position where the ion trap chip 110 is placed can be made as close as possible to the light-transmitting window so that the distance from the objective lens 161 to the ion trap chip 110 does not exceed 30 mm, and no limitation is made here.
[0112] In some possible implementation manners, the objective lens 161 can also be disposed in the internal space of the vacuum housing 131, so that the distance between the objective lens 161 and the ion trap chip 110 is not limited by the light-transmitting window, that is, the distance between the objective lens 161 and the ion trap chip 110 can be no greater than the working distance of the objective lens 161. Exemplarily, the objective lens 161 is placed in the internal space of the vacuum housing 131, and an adapter is added near the ion trap chip 110 to fix the objective lens 161. Then, when the charged ions in the ion trap chip 110 emit photons, the photons first reach the objective lens 161, the objective lens 161 refracts the photons, and the refracted photons reach the camera 162 through the light-transmitting window. Since the distance between the objective lens 161 and the ion trap chip 110 is not limited by the light-transmitting window, an objective lens 161 with a larger NA can be used, so that the working distance of the objective lens 161 is further shortened, for example, several millimeters.
[0113] When the ion trap chip 110 is disposed between the first dry cold plate 330 and the wet cold plate 240, the ion trap chip 110 is clamped by the first dry cold plate 330 and the wet cold plate 240 to fix the ion trap chip 110. However, during the installation process of the first dry cold plate 330 and the wet cold plate 240, a system error may occur, resulting in the distance between the first dry cold plate 330 and the wet cold plate 240 being inconsistent with the length of the ion trap chip 110, so that the ion trap chip 110 cannot be fixed between the first dry cold plate 330 and the wet cold plate 240.
[0114] For this reason, in some possible implementation manners, the first dry cold plate 330 and the wet cold plate 240 can be respectively designed as trapezoids, so that the contact surface between the wet cold plate 240 and the ion trap chip 110 forms a first angle θ1 with the horizontal plane, the contact surface between the first dry cold plate and the sample forms a second angle θ2 with the horizontal plane, and the directions of the first angle θ1 and the second angle θ2 are opposite, so that the wet cold plate 240 and the first dry cold plate 330 form a wedge-shaped structure, and this wedge-shaped structure is used to fix the position of the ion trap chip 110.
[0115] Exemplarily, when installing the first dry cold plate 330 and the wet cold plate 240, the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240 should be designed as the length of the ion trap chip 110. However, there may be systematic errors, resulting in the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240 being greater than or less than the length of the ion trap chip 110. Then, in the wedge-shaped structure formed by the first dry cold plate 330 and the wet cold plate 240, the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240 is greater than the distance of the narrower side and less than the distance of the wider side. Then, the ion trap chip 110 can be installed from the wider side to the narrower side, so that the ion trap chip can be stuck at a certain position between the first dry cold plate 330 and the wet cold plate 240.
[0116] Exemplarily, as Figure 13 shown, the first dry cold plate 330 and the wet cold plate 240 form a wedge-shaped structure that is narrower on the left and wider on the right (wherein, the objective lens 161 is arranged on the left side of the ion trap chip 110). Then, the ion trap chip 110 can be installed from right to left between the first dry cold plate 330 and the wet cold plate 240 until the ion trap chip 110 is completely stuck between the first dry cold plate 330 and the wet cold plate 240.
[0117] In some possible implementation manners, the wedge-shaped structure formed by the first dry cold plate 330 and the wet cold plate 240 can also be wider on the left and narrower on the right (wherein, the objective lens 161 is arranged on the left side of the ion trap chip 110). Then, the ion trap chip 110 can be installed from left to right between the first dry cold plate 330 and the wet cold plate 240 until the ion trap chip 110 is completely stuck between the first dry cold plate 330 and the wet cold plate 240. This is not limited herein.
[0118] Next, taking the case where Figure 13 shown, the first dry cold plate 330 and the wet cold plate 240 form a wedge-shaped structure that is narrower on the left and wider on the right (wherein, the objective lens 161 is arranged on the left side of the ion trap chip 110) as an example for illustration.
[0119] Exemplarily, θ1 = θ2 = θ. Assuming that the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240 is X (for example, in millimeters) longer than the length of the ion trap chip 110, then the ion trap chip 110 moves horizontally by X * tan from the middle position between the first dry cold plate 330 and the wet cold plate 240 -1θ / 2, the ion trap chip 110 can reach the target position where it can be stably fixed between the first dry cold plate 330 and the wet cold plate 240. It should be noted that if the ion trap chip 110 is longer than the distance between the middle positions of the first dry cold plate 330 and the wet cold plate 240, then X is a positive number; otherwise, X is a negative number.
[0120] Since the objective lens 161 has a fixed working distance, when the position of the ion trap chip 110 is determined, that is, it is displaced by X*tan -1 θ / 2 from the middle position between the first dry cold plate 330 and the wet cold plate 240, in order to keep the working distance of the objective lens 161 unchanged, it is also necessary to displace by X*tan -1 θ / 2 based on the position of the ion trap chip 110.
[0121] Exemplarily, the light-passing window of the vacuum housing 131 is designed in the form of an inverted viewing window, that is, the objective lens 161 is placed outside the vacuum housing 131, and the light-passing window of the vacuum housing 131 is arranged between the objective lens 161 and the ion trap chip 110. As Figure 14 shown, let d be the working distance of the objective lens 161, d1 be the distance from the objective lens 161 to the light-passing window, t be the thickness of the light-passing window, and d2 be the distance from the light-passing window to the ion trap chip 110, that is, d = d1 + t + d2.
[0122] In some possible implementation manners, if X is a positive number, then the ion trap chip 110 moves in the opposite direction of the light-passing window by X*tan -1 θ / 2, and it is required that the objective lens 161 moves in the same direction by X*tan -1 θ / 2. Since the objective lens 161 is arranged outside the vacuum housing 131 and cannot break through the light-passing window, it is required that the moving distance of the objective lens 161 does not exceed the distance between the objective lens 161 and the light-passing window, that is, it is required that d1 > X*tan -1 θ / 2.
[0123] Exemplarily, if d1 = 5 (mm) and θ = 30°, based on d1 > X*tan -1 θ / 2, we can get 5 > X*tan -1 30° / 2, that is, X < 5.77 (mm). That is, in this case, 5.77 (mm) is the upper limit of the systematic error between the distance between the first dry cold plate 330 and the wet cold plate 240 and the length of the ion trap chip 110.
[0124] In some possible implementation manners, as Figure 14 shown, if X is a negative number, then the ion trap chip 110 moves in the direction of the light-passing window by -X*tan -1θ / 2, then d2 becomes smaller. Since the objective lens 161 is arranged outside the vacuum housing 131, the objective lens 161 moves in the direction away from the light passing window by -X*tan -1 θ / 2. In some possible implementation manners, such as Figure 15 shown, a second shim can also be padded on the first dry cold plate 330 and / or a second shim can be padded on the wet cold plate 240. By increasing or decreasing the shim, the distance between the first dry cold plate 330 and the wet cold plate 240 can be made smaller, so that the ion trap chip 110 moves to the right to offset the displacement change caused by X.
[0125] In some possible implementation manners, if the objective lens 161 is placed in the internal space of the vacuum housing, when the ion trap chip 110 moves in the opposite direction of the light passing window by X*tan -1 θ / 2, the position of the objective lens 161 can be adjusted by an electric displacement stage. It should be noted that the stroke of some electric displacement stages is limited by the displacement length. Then the displacement range of the objective lens 161 is not greater than the limit of the displacement length. Based on the limit of the displacement length, the upper limit of the assembly error between the first dry cold plate 330 and the wet cold plate 240 can also be determined. Exemplarily, the displacement range of the electric displacement stage is 5 mm. Therefore, X*tan -1 θ / 2 should not be greater than 5 mm.
[0126] In some possible implementation manners, the laser system 150 can include multiple laser devices, and the multiple laser devices are respectively used to align the ion trap chip 110. In some possible implementation manners, such as Figure 16 shown, the multiple laser devices are outside the vacuum housing 131, and the multiple laser devices can also be arranged in an inverted window structure.
[0127] Exemplarily, such as Figure 17 shown, the laser light emitted by the laser device 1 and the laser device 2 to the ion trap chip 110 respectively is addressing light, and the laser light emitted by the laser devices in other directions to the ion trap chip 110 can be used to achieve atomic ionization, ion cooling, detection, etc.
[0128] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A refrigeration system, characterized in that, Comprising: A wet refrigeration system and a dry refrigeration system. Among them, the wet refrigeration system includes a wet refrigerator, a liquid helium pipeline, a liquid helium cavity, and a wet cold plate. The dry refrigeration system includes a dry refrigerator, a helium pipeline, and a first dry cold plate. The liquid helium pipeline is used to connect the wet refrigerator and the liquid helium cavity, and the helium pipeline is used to connect the dry refrigerator and the first dry cold plate; The wet refrigerator is used to transmit liquid helium to the liquid helium cavity through the liquid helium pipeline; The liquid helium cavity is used to contact the wet cold plate and refrigerate the wet cold plate through the liquid helium; The dry refrigerator is used to transmit first high-pressure helium gas to the first dry cold plate through the helium pipeline, and the first high-pressure helium gas is used to refrigerate the first dry cold plate; The first dry cold plate is used to contact the sample and refrigerate the sample; The wet cold plate is used to contact the sample and refrigerate the sample.
2. The refrigeration system according to claim 1, wherein The sample is a columnar structure and is vertically placed; The wet cold plate is arranged above the sample, and the liquid helium cavity is arranged above the wet cold plate; The first dry cold plate is arranged below the sample.
3. The refrigeration system according to claim 1 or 2, characterized in that, Further comprising: A vacuum system, the vacuum system includes a vacuum housing, a vacuum flange, and a vacuum pump; wherein, The vacuum housing is a sealed hollow cavity. The internal space of the vacuum housing is used to accommodate the wet cold plate, the first dry cold plate, and the sample. The wet refrigerator and the dry refrigerator are respectively arranged in the external space of the vacuum housing; The vacuum pump is arranged on the vacuum housing and is used to evacuate the vacuum housing so that a vacuum environment is formed in the internal space of the vacuum housing; The vacuum flange is arranged on the vacuum housing and is used to provide an inlet and outlet for devices between the internal space and the external space of the vacuum housing; The liquid helium pipeline penetrates the vacuum housing to connect the wet refrigerator and the wet cold plate; The helium pipeline penetrates the vacuum housing to connect the dry refrigerator and the first dry cold plate.
4. The refrigeration system according to claim 3, characterized in that, Further comprising: A thermal shielding system, the thermal shielding system is arranged in the internal space of the vacuum housing; The thermal shielding system includes a first thermal shielding layer; The first thermal shielding layer is a cylindrical structure and is arranged around the sample in the horizontal direction and is used to shield thermal radiation for the sample.
5. The refrigeration system according to claim 4, wherein The thermal shielding system further includes a second thermal shielding layer; The second thermal shielding layer is a barrel-shaped structure with an opening facing the first dry cold plate. The second thermal shielding layer is arranged around and below the first dry cold plate and is used to shield thermal radiation for the first dry cold plate; The dry refrigeration system further includes a second dry cold plate, and the helium pipeline is further used to connect the second dry cold plate. The second dry cold plate contacts the second thermal shielding layer and refrigerates the second thermal shielding layer; The dry refrigerator is further used to transmit second high-pressure helium gas to the second dry cold plate through the helium pipeline.
6. The refrigeration system according to claim 4 or 5, characterized in that the thermal shielding system further includes a third thermal shielding layer; the third thermal shielding layer is a barrel-shaped structure with an opening facing the wet cold plate, and the third thermal shielding layer is arranged around and above the wet cold plate for shielding thermal radiation for the wet cold plate; the wet refrigeration system further includes a liquid nitrogen pipeline and a liquid nitrogen cavity, and the liquid nitrogen pipeline penetrates through the vacuum outer shell for connecting the liquid nitrogen cavity and the wet refrigerator; the wet refrigerator is further configured to transfer liquid nitrogen to the liquid nitrogen cavity through the liquid nitrogen pipeline; the liquid nitrogen cavity contacts the third thermal shielding layer for cooling the third thermal shielding layer through the liquid nitrogen.
7. The refrigeration system according to claim 6, characterized in that the second thermal shielding layer and the third thermal shielding layer are connected by a thermal insulation connecting member.
8. The refrigeration system according to claim 7, wherein, The material of the thermal insulation connecting member is constantan or polyether ether ketone PEEK.
9. The refrigeration system according to claim 6, characterized in that the diameter of the opening of the second thermal shielding layer is smaller than the diameter of the opening of the third thermal shielding layer, and a part of the opening of the second thermal shielding layer is embedded in the inner space of the third thermal shielding layer, and there is no contact between the second thermal shielding layer and the third thermal shielding layer; or, the diameter of the opening of the third thermal shielding layer is smaller than the diameter of the opening of the second thermal shielding layer, and a part of the opening of the third thermal shielding layer is embedded in the inner space of the second thermal shielding layer, and there is no contact between the third thermal shielding layer and the second thermal shielding layer.
10. An ion trap system, characterized in that, Comprising: an ion trap chip, a fluorescence detection device, a laser system, and the refrigeration system according to any one of claims 1-9, wherein the sample is the ion trap chip; the laser system for sending laser to the ion trap chip; the fluorescence detection device for receiving photons emitted by the ion trap chip.
11. The ion trap system according to claim 10, characterized in that the fluorescence detection device includes an objective lens and a camera; the objective lens for refracting photons emitted by the ion trap chip to the camera; the camera for receiving photons refracted by the objective lens and converting them into electrical signals; wherein the camera is arranged in the outer space of the vacuum outer shell, the vacuum outer shell further includes a light-transmitting window, the through window is a light-transmitting material, and the camera, the light-transmitting window and the ion trap chip are on a straight line so that photons emitted by the ion trap chip pass through the light-transmitting window and are received by the camera.
12. The ion trap system according to claim 11, characterized in that the light-transmitting window is a concave structure on the vacuum outer shell; the objective lens is arranged in the outer space of the vacuum outer shell, and the objective lens is adjacent to the light-transmitting window, and the distance between the objective lens and the ion trap chip is not greater than the working distance of the objective lens.
13. The ion trap system according to claim 12, characterized in that The contact surface between the wet cold plate and the ion trap chip forms a first angle with the horizontal plane, and the contact surface between the first dry cold plate and the ion trap chip forms a second angle with the horizontal plane. The directions of the first angle and the second angle are opposite, so that the wet cold plate and the first dry cold plate form a wedge-shaped structure, and the wedge-shaped structure is used to fix the position of the ion trap chip.
14. The ion trap system according to claim 13, wherein It further includes: a first adjustment piece and / or a second adjustment piece; The first adjustment piece is arranged above the wet cold plate to adjust the position of the wet cold plate in the vertical direction; The second adjustment piece is arranged below the first dry cold plate to adjust the position of the first dry cold plate in the vertical direction.
15. The ion trap system according to claim 11, wherein the objective lens is arranged in the internal space of the vacuum housing, and the distance between the objective lens and the ion trap chip is not greater than the working distance of the objective lens.