Shielding cover for refrigerating machine, refrigerating machine and quantum computer

Abstract

The invention provides a shielding case for a refrigerating machine, the refrigerating machine and a quantum computer, and relates to the technical field of quantum computing. The refrigerator includes a sample chamber. The shielding cover and the sample chamber are correspondingly arranged, and the shielding cover comprises a magnetic field shielding layer wrapping the sample chamber and an infrared absorption layer wrapping the sample chamber. According to the technical scheme provided by the invention, the shielding cover and the sample chamber are correspondingly arranged, so that the magnetic field noise suffered by the sample chamber is improved through the magnetic field shielding layer wrapping the sample chamber; and through the infrared absorption layer wrapping the sample chamber, infrared photon thermal noise radiated to the sample chamber in the refrigerating machine is improved, and the purpose of improving the influence of magnetic field noise and thermal noise on the sample chamber is achieved, so that a working environment with less noise is provided for quantum bits, a quantum amplifier and the like of a quantum processor in the sample chamber, and the working efficiency is improved. And the performance of the quantum computer is improved.

Description

Technical Field

[0001] The present application relates to the field of quantum computing technology, and more specifically, to a shielding cover for a refrigerator, a refrigerator, and a quantum computer. Background Art

[0002] Research on quantum technology, particularly quantum computers, has become a global research hotspot in science and technology. As a cutting-edge computing platform, quantum computers, by utilizing superconducting quantum bits (qubits) for information processing, have enormous potential and can solve complex problems that traditional computers cannot efficiently handle. Fully leveraging the advantages of quantum computers and improving their performance present numerous technical challenges. For example, quantum computers perform various gate operations on superconducting qubits at extremely low temperatures, approximately 10mK, to generate quantum computing results. However, superconducting qubits are not robust and are susceptible to magnetic field noise and thermal noise even at extremely low temperatures. This reduces the longitudinal and transverse relaxation times of superconducting qubits, diminishing their lifetime and phase coherence, severely impacting the performance of quantum computers. Summary of the Invention

[0003] In view of this, the present application provides a shielding cover for a refrigerator, a refrigerator and a quantum computer, which effectively solves the technical problems existing in the prior art, improves the influence of magnetic field noise and thermal noise on the sample chamber, thereby providing a less noisy working environment for the quantum bits, quantum amplifiers, etc. of the quantum processor in the sample chamber, and improves the performance of the quantum computer.

[0004] To achieve the above objectives, the technical solutions provided by this application are as follows:

[0005] A shielding cover for a refrigerator, the refrigerator comprising a sample chamber, the shielding cover being arranged corresponding to the sample chamber, wherein the shielding cover comprises a magnetic field shielding layer wrapping the sample chamber, and an infrared absorption layer wrapping the sample chamber.

[0006] Optionally, the magnetic field shielding layer includes at least one of a magnetic field repulsion layer wrapping the sample chamber and a high magnetic permeability layer wrapping the sample chamber, and the magnetic permeability of the high magnetic permeability layer is greater than 100 kH / m;

[0007] Wherein, when the magnetic field shielding layer includes the magnetic field repulsion layer and the high magnetic permeability layer, the magnetic field repulsion layer is located on the side of the high magnetic permeability layer facing the sample chamber, or the magnetic field repulsion layer is located on the side of the high magnetic permeability layer facing away from the sample chamber.

[0008] Optionally, the infrared absorption layer is located on a side of the magnetic field shielding layer facing the sample chamber;

[0009] Alternatively, the infrared absorption layer is located on the side of the magnetic field shielding layer facing away from the sample chamber;

[0010] Alternatively, when the magnetic field shielding layer includes the magnetic field repelling layer and the high magnetic permeability layer, the infrared absorbing layer is located between the magnetic field repelling layer and the high magnetic permeability layer.

[0011] Optionally, the magnetic field repulsion layer is a superconductor layer.

[0012] Optionally, the high magnetic permeability layer is a Permalloy layer or an Iron-Chromium-Cobalt alloy layer.

[0013] Optionally, the thickness of the magnetic field shielding layer is no more than 2 mm.

[0014] Optionally, the infrared absorbing layer is a mixed coating of resin and semiconductor particles.

[0015] Optionally, the shielding cover is a barrel-shaped shielding cover, and the barrel-shaped shielding cover includes a connecting portion extending out of its opening;

[0016] The refrigerator comprises a mixing chamber cold plate arranged opposite to the sample chamber, the barrel-shaped shielding cover wraps the sample chamber, and is fixedly connected to the mixing chamber cold plate via the connecting portion.

[0017] Optionally, the connecting portion and the mixing chamber cold plate are fixed by screws.

[0018] Optionally, when the magnetic field shielding layer includes one of the magnetic field repelling layer and the high magnetic permeability layer, there is no gap between the one of the magnetic field repelling layer and the high magnetic permeability layer and the infrared absorption layer; or,

[0019] When the magnetic field shielding layer includes the magnetic field repelling layer and the high magnetic permeability layer, any two adjacent layers among the magnetic field repelling layer, the high magnetic permeability layer and the infrared absorbing layer are arranged without a gap.

[0020] Based on the same inventive concept, the present application also provides a refrigerator, wherein:

[0021] Sample room;

[0022] A shielding cover is provided corresponding to the sample chamber, wherein the shielding cover is the shielding cover for the refrigerator mentioned above.

[0023] Optionally, the refrigerator includes a mixing chamber cold plate arranged opposite to the sample chamber;

[0024] The shielding cover is a barrel-shaped shielding cover, and the barrel-shaped shielding cover includes a connecting portion extending out of its opening; the barrel-shaped shielding cover wraps the sample chamber and is connected and fixed to the mixing chamber cold plate through the connecting portion.

[0025] Optionally, the refrigerator comprises a dilution refrigerator.

[0026] Based on the same inventive concept, the present application also provides a quantum computer, which includes the above-mentioned refrigerator.

[0027] Optionally, the quantum computer includes a superconducting quantum computer.

[0028] Compared with the existing technology, the technical solution provided by this application has at least the following advantages:

[0029] The present application provides a shielding cover for a refrigerator, a refrigerator, and a quantum computer. The refrigerator includes a sample chamber; the shielding cover is arranged in correspondence with the sample chamber, wherein the shielding cover includes a magnetic field shielding layer that encloses the sample chamber, and an infrared absorption layer that encloses the sample chamber. The technical solution provided by the present application arranges the shielding cover in correspondence with the sample chamber, thereby improving the magnetic field noise experienced by the sample chamber by enclosing the magnetic field shielding layer of the sample chamber; and improving the thermal noise of infrared photons radiated from the refrigerator to the sample chamber by enclosing the infrared absorption layer of the sample chamber, thereby achieving the purpose of improving the influence of magnetic field noise and thermal noise experienced by the sample chamber, thereby providing a less noisy working environment for the quantum bits, quantum amplifiers, etc. of the quantum processor in the sample chamber, and improving the performance of the quantum computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0031] Figure 1 A schematic diagram of a partial structure of a refrigerator provided in an embodiment of the present application;

[0032] Figure 2 for Figure 1 Section along AA' direction;

[0033] Figure 3 A schematic structural diagram of a shielding cover provided in an embodiment of the present application;

[0034] Figure 4 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0035] Figure 5 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0036] Figure 6 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0037] Figure 7 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0038] Figure 8 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0039] Figure 9 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0040] Figure 10 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0041] Figure 11 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0042] Figure 12 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0043] Figure 13 A schematic structural diagram of another shielding cover provided in an embodiment of the present application;

[0044] Figure 14 A schematic structural diagram of another shielding cover provided in an embodiment of the present application.

[0045] Reference numerals:

[0046] 10-refrigeration machine; 101-pulse tube cold head; 102-50K cold plate; 103-4K cold plate; 104-distillation chamber; 105-continuous heat exchanger; 106-silver powder sintering heat exchanger; 107-mixing chamber; 108-mixing chamber cold plate; 100-sample chamber; 200-shielding cover; 210-magnetic field shielding layer; 211-magnetic field repelling layer; 212-high magnetic permeability layer; 220-infrared absorption layer; 201-connecting part; 202-screws. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] As described in the background technology, the research on quantum technology, especially quantum computers, has become a research hotspot in the field of science and technology around the world. As a cutting-edge computing platform, quantum computers have great potential by utilizing superconducting quantum bits (qubits) for information processing, and can solve complex problems that traditional computers cannot handle efficiently. To give full play to the advantages of quantum computers and improve their performance, there are many technical challenges. For example, quantum computers perform various gate operations on superconducting quantum bits in an extremely low temperature environment of about 10mK to obtain quantum computing results. However, superconducting quantum bits have poor robustness and are easily affected by magnetic field noise and thermal noise even at extremely low temperatures, thereby reducing the longitudinal and transverse relaxation times of superconducting quantum bits, reducing their lifetime and phase coherence, and seriously affecting the performance of quantum computers.

[0049] Based on this, the embodiments of the present application provide a shielding cover for a refrigerator, a refrigerator, and a quantum computer, which effectively solve the technical problems existing in the prior art, improve the influence of magnetic field noise and thermal noise on the sample chamber, thereby providing a less noisy working environment for the quantum bits, quantum amplifiers, etc. of the quantum processor in the sample chamber, and improving the performance of the quantum computer.

[0050] To achieve the above purpose, the technical solutions provided in the embodiments of the present application are as follows, specifically combined with Figures 1 to 14 The technical solutions provided in the embodiments of the present application are described in detail.

[0051] Combine Figure 1 and Figure 2 As shown, Figure 1 This is a partial structural diagram of a refrigerator provided in an embodiment of the present application. Figure 2 for Figure 1 The cross-sectional view along the AA' direction, that is Figure 2The structural layers of the shielding cover are specifically illustrated. The refrigerator 10 provided in the embodiment of the present application includes a sample chamber 100. A shielding cover 200 is disposed corresponding to the sample chamber 100. The shielding cover 200 includes a magnetic field shielding layer 210 that surrounds the sample chamber 100, and an infrared absorption layer 220 that surrounds the sample chamber 100. It is understood that the refrigerator 10 provided in the embodiment of the present application is one of the most important core components of a quantum computer and the core cryogenic support system of the quantum computer. The sample chamber 100 of the refrigerator 10 is a key area for enabling the ultra-low temperature operation of quantum bits. Specifically, the sample chamber 100 of the refrigerator 10 is used to house quantum processors, quantum amplifiers, and the like. For example, a quantum processor can be directly mounted on the lower surface of the mixing chamber cold plate 108 facing the sample chamber 100 (or connected to the lower surface of the mixing chamber cold plate 108 via a superconducting thermal link). The sample chamber 100 ensures that the quantum processor's temperature is consistent with that of the mixing chamber 107, enabling the quantum computer to perform various gate operations on the quantum bits in an ultra-low temperature environment, thereby obtaining quantum computation results. Based on this, the shielding cover 200 is disposed in correspondence with the sample chamber 100. The magnetic field shielding layer 210 surrounding the sample chamber 100 reduces magnetic field noise experienced by the sample chamber 100. Furthermore, the infrared absorption layer 220 surrounding the sample chamber 100 reduces thermal noise of infrared photons radiated from the refrigerator 10 to the sample chamber 100. This achieves the goal of reducing the effects of magnetic field noise and thermal noise experienced by the sample chamber 100, thereby providing a less noisy operating environment for the quantum bits and quantum amplifiers of the quantum processor in the sample chamber 100, thereby improving the performance of the quantum computer. Optionally, the quantum processor provided in the embodiments of the present application may include a superconducting quantum chip or other suitable types of quantum processors. The quantum amplifier may include a quantum dot amplifier, a parametric amplifier (e.g., a Cerfson parametric amplifier or a traveling-wave parametric amplifier), or other suitable types of quantum amplifiers. The specific selection of these depends on the type of refrigerator 10 and quantum computer. This application does not impose any specific restrictions on the types of quantum processors and quantum amplifiers.

[0052] In some embodiments, the refrigerator 10 provided in the embodiment of the present application may be a dilution refrigerator (DR), or may be other suitable types of refrigerators, which are not specifically limited in the present application. Figure 1As shown, the refrigerator 10 provided in the embodiment of the present application further includes a pulse tube cold head 101 located above the sample chamber 100, a 50K cold plate 102 located between the pulse tube cold head 101 and the sample chamber 100, a 4K cold plate 103 located between the 50K cold plate 102 and the sample chamber 100, a distillation chamber 104 located between the 4K cold plate 103 and the sample chamber 100, a continuous heat exchanger 105 located between the distillation chamber 104 and the sample chamber 100, a silver powder sintered heat exchanger 106 located between the continuous heat exchanger 105 and the sample chamber 100, a mixing chamber 107 located between the silver powder sintered heat exchanger 106 and the sample chamber 100, and a mixing chamber cold plate 108 located between the mixing chamber 107 and the sample chamber 100. The pulse tube cold head 101 is the core power source of the refrigerator 10, generating low temperatures through a compression-expansion cycle of a gas (e.g., helium), and pre-cooling can be achieved without the need for liquid helium. The 50K cold plate 102 is the first stage pre-cooling platform, intercepting high temperature heat radiation and cooling the radiation shielding layer; the 50K cold plate 102 is usually made of high purity copper, with a polished surface to reduce heat radiation absorption. The 4K cold plate 103 is the second stage pre-cooling platform, providing a basic low temperature environment for the distillation chamber 104 and the heat exchanger; the 4K cold plate 103 needs to maintain a temperature fluctuation of less than 0.1K to ensure 3 He is effectively condensed. The distillation chamber 104 selectively evaporates by heating 3 He, the driver 3 He cycle, and separation 3 He and 4 He, maintain the purity of the working medium. The continuous heat exchanger 105 and the silver powder sintered heat exchanger 106 constitute the heat exchanger system of the refrigerator 10. The continuous heat exchanger 105 is a multi-stage countercurrent heat exchanger, which makes the returned coolant 3 He (dilute phase) pre-cools the incoming warm 3 He (concentrated phase) to improve refrigeration efficiency; the continuous heat exchanger 105 is a spiral coil or microchannel structure to maximize its surface area. The silver powder sintered heat exchanger 106 is used to further optimize heat exchange in the ultra-low temperature range, using the porous structure of the silver powder sintered to enhance heat transfer; the silver powder sintered heat exchanger 106 can reduce the inlet of the mixing chamber 107 3 He temperature, directly improves the stability of the quantum bit working environment. The mixing chamber 107 is used to 3 He is diluted from the concentrated phase to 4 He is in a superfluid phase, absorbing heat to achieve mK-level refrigeration; the mixing chamber cold plate 108 is a direct cooling platform for the quantum processor, which is thermally connected to the chip through indium crimping or superconducting aluminum wire. The quantum processor is installed on the lower surface of the mixing chamber cold plate 108 facing the sample chamber 100.

[0053] It should be noted that the specific structure of the refrigerator 10 described above is an optional embodiment of the present application. It is understood that in other modified embodiments, the structure of the refrigerator 10 may also be other suitable structures. The key point of the invention of this application is that the structure of the shielding cover 200 includes at least one of the magnetic field repelling layer 211 and the high magnetic permeability layer 212, and includes the infrared absorbing layer 220. Therefore, for those skilled in the art, any identical or similar improvements to the shielding cover 200 should fall within the scope of protection of this application. The improvements to the shielding cover 200 are described in detail below.

[0054] In some embodiments, the magnetic field shielding layer 210 provided in the embodiment of the present application may be an independent structural layer, or may be a structural layer composed of at least two stacked layers, which is not specifically limited in the present application. Figures 3 to 12 The structure of the shielding cover 200 provided in the embodiment of the present application is described in detail. The magnetic field shielding layer 210 provided in the embodiment of the present application includes at least one of a magnetic field repelling layer 211 enclosing the sample chamber 100 and a high magnetic permeability layer 212 enclosing the sample chamber 100, and an infrared absorbing layer 220. The high magnetic permeability layer 212 has a magnetic permeability greater than 100 kH / m. The magnetic field repulsion layer 211 has a repulsive effect on the magnetic field, and the magnetic flux lines cannot pass through the magnetic field repulsion layer, thereby improving the magnetic field noise experienced by the sample chamber 100; the high magnetic permeability layer 212 can change the path of the magnetic flux lines, so that the magnetic flux lines are preferentially distributed along its surface and cannot penetrate the high magnetic permeability layer 212 into the sample chamber 100, further improving the magnetic field noise experienced by the sample chamber 100; the infrared absorption layer 220 improves the thermal noise of infrared photons radiated from the refrigerator 10 to the sample chamber 100, thereby achieving the purpose of improving the influence of thermal noise experienced by the sample chamber 100, thereby providing a less noisy working environment for the quantum bits, quantum amplifiers, etc. of the quantum processor in the sample chamber 100, thereby improving the performance of the quantum computer. When the magnetic field shielding layer 210 includes the magnetic field repulsion layer 211 and the high magnetic permeability layer 212 , the magnetic field repulsion layer 211 is located on the side of the high magnetic permeability layer 212 facing the sample chamber 100 , or the magnetic field repulsion layer 211 is located on the side of the high magnetic permeability layer 212 facing away from the sample chamber 100 .

[0055] In some embodiments, in the shielding cover 200 provided in the embodiment of the present application, the infrared absorption layer 220 can be arranged on the side of the magnetic field shielding layer 210 facing the sample chamber 100; or, the infrared absorption layer 220 can be arranged on the side of the magnetic field shielding layer 210 facing away from the sample chamber 100; or, when the magnetic field shielding layer 210 is composed of at least two stacked layers, the infrared absorption layer 220 can also be arranged between the stacked layers in the magnetic field shielding layer 210, and this needs to be specifically designed according to the actual application. That is, the infrared absorption layer 220 provided in the embodiment of the present application is located on the side of the magnetic field shielding layer 210 facing the sample chamber 100; or, the infrared absorption layer 220 is located on the side of the magnetic field shielding layer 210 facing away from the sample chamber 100; or, when the magnetic field shielding layer 210 includes the magnetic field repulsion layer 211 and the high magnetic permeability layer 212, the infrared absorption layer 220 is located between the magnetic field repulsion layer 211 and the high magnetic permeability layer 212.

[0056] Furthermore, when the magnetic field shielding layer 210 includes one of the magnetic field repulsion layer 211 and the high magnetic permeability layer 212, there is no gap between the magnetic field repulsion layer 211 and the high magnetic permeability layer 212 and the infrared absorption layer 220; or, when the magnetic field shielding layer 210 includes the magnetic field repulsion layer 211 and the high magnetic permeability layer 212, there is no gap between any two adjacent layers of the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220. This not only ensures high heat conduction efficiency between structural layers and ensures that the temperature of the shielding cover 200 is reduced in time, but also enables the structural layers to protect each other, thereby improving the oxidation problem of the structural layers and improving the reliability of the shielding cover 200. Specifically, Figure 3 and Figure 4 As shown, Figure 3 A schematic diagram of the structure of a shielding cover provided in an embodiment of the present application is shown in FIG. Figure 4 This is a schematic structural diagram of another shielding cover provided in an embodiment of the present application, wherein the magnetic field shielding layer 210 provided in an embodiment of the present application may only include a magnetic field repelling layer 211 that wraps the sample chamber 100. Figure 3 As shown, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the magnetic field repulsion layer 211 facing the sample chamber 100; there is no gap between the magnetic field repulsion layer 211 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211 and the infrared absorption layer 220 are in contact and fixed. Or as Figure 4 As shown, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the magnetic field repulsion layer 211 facing away from the sample chamber 100; there is no gap between the magnetic field repulsion layer 211 provided in the embodiment of the present application and the infrared absorption layer 220, and the magnetic field repulsion layer 211 and the infrared absorption layer 220 are in contact and fixed.

[0057] like Figure 5 and Figure 6 As shown, Figure 5 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. Figure 6 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application, wherein the magnetic field shielding layer 210 provided in an embodiment of the present application may only include a high magnetic permeability layer 212 that wraps the sample chamber 100. Figure 5 As shown, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing the sample chamber 100; there is no gap between the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed. Or as Figure 6 As shown, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing away from the sample chamber 100; there is no gap between the high magnetic permeability layer 212 provided in the embodiment of the present application and the infrared absorption layer 220, and the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed.

[0058] like Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. Figure 8 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application, wherein the magnetic field shielding layer 210 provided in the embodiment of the present application includes a magnetic field repelling layer 211 that wraps the sample chamber 100, and also includes a high magnetic permeability layer 212 that wraps the sample chamber 100. In addition, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the magnetic field shielding layer 210 facing the sample chamber 100. Figure 7 As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing the sample chamber 100, that is, the magnetic field repulsion layer 211 is located between the infrared absorption layer 220 and the high magnetic permeability layer 212; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed. Or as Figure 8 As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing away from the sample chamber 100, that is, the high magnetic permeability layer 212 is located between the infrared absorption layer 220 and the magnetic field repulsion layer 211; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed.

[0059] like Figure 9 and Figure 10As shown, Figure 9 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. Figure 10 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application, wherein the magnetic field shielding layer 210 provided in the embodiment of the present application includes a magnetic field repulsion layer 211 that wraps the sample chamber 100, and also includes a high magnetic permeability layer 212 that wraps the sample chamber 100. In addition, the infrared absorption layer 220 provided in the embodiment of the present application can be located on the side of the magnetic field shielding layer 210 that faces away from the sample chamber 100. Figure 9 As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing the sample chamber 100, that is, the high magnetic permeability layer 212 is located between the magnetic field repulsion layer 211 and the infrared absorption layer 220; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed. Or as Figure 10 As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing away from the sample chamber 100, that is, the magnetic field repulsion layer 211 is located between the high magnetic permeability layer 212 and the infrared absorption layer 220; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed.

[0060] like Figure 11 and Figure 12 As shown, Figure 11 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. Figure 12 This is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application, wherein the magnetic field shielding layer 210 provided in the embodiment of the present application includes a magnetic field repelling layer 211 that wraps the sample chamber 100, and also includes a high magnetic permeability layer 212 that wraps the sample chamber 100. In addition, the infrared absorption layer 220 provided in the embodiment of the present application can be located between the magnetic field repelling layer 211 and the high magnetic permeability layer 212. Figure 11 As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing the sample chamber 100; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed. Or as Figure 12As shown, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be located on the side of the high magnetic permeability layer 212 facing away from the sample chamber 100; there is no gap between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 provided in the embodiment of the present application, and the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are in contact and fixed.

[0061] Combine Figures 1 to 12 As shown, the shielding cover 200 provided in the embodiment of the present application is designed in a style of wrapping the sample chamber 100, so that the shielding cover 200 can be specifically a barrel-shaped structure, that is, the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 can be designed as a barrel-shaped structure, and according to the relationship between the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 as the inner layer and the outer layer, the magnetic field repulsion layer 211, the high magnetic permeability layer 212 and the infrared absorption layer 220 are designed as a nested structure, and the present application does not make any specific restrictions on this.

[0062] In some embodiments, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be a superconductor layer. Among them, the superconductor layer has a Meissner effect, that is, it has a repulsive effect on the magnetic field, and the superconductor layer will generate currents on its surface. The magnetic fields of these surface currents and the external magnetic field noise cancel each other out in the superconductor layer, so that the magnetic flux lines cannot pass through the superconductor layer and enter the sample chamber 100. For example, the magnetic field repulsion layer 211 provided in the embodiment of the present application can be a pure aluminum layer, and the impurity content of the pure aluminum layer is less than 1%. When the refrigerator 10 is running, the temperature of the sample chamber 100 is 10mK-20mK, and the superconducting transition temperature of the pure aluminum layer is 1.175K, and the pure aluminum layer will be transformed into a superconductor. The pure aluminum layer has a Meissner effect, and the pure aluminum layer will generate currents on its surface. The magnetic fields of these surface currents and the external magnetic field noise cancel each other out in the superconductor layer, thereby achieving the purpose of repelling the magnetic field, so that the magnetic flux lines cannot pass through the superconductor layer and enter the sample chamber 100. In addition, the magnetic field repulsion layer 211 provided in the embodiment of the present application can also be a superconductor layer made of other materials, such as germanium, and the specific selection needs to be based on the actual application. The magnetic field repulsion layer 211 provided in the embodiment of the present application can be prepared into a barrel shape by sheet metal and welding processing to facilitate wrapping the sample chamber 100 after installation.

[0063] The high magnetic permeability layer 212 provided in the embodiment of the present application can be a Permalloy layer or an iron-chromium-cobalt alloy layer. The Permalloy layer is composed of about 70% nickel, about 20% iron and about 10% copper and molybdenum, and has extremely high relative magnetic permeability and low coercive force. The extremely high magnetic permeability Permalloy layer will change the path of the magnetic flux lines, so that the magnetic flux lines are preferentially distributed along the surface of the Permalloy layer, and the magnetic flux lines cannot pass through the surface of the Permalloy layer, thereby eliminating the magnetic field inside the Permalloy layer. The high magnetic permeability layer 212 provided in the embodiment of the present application can be prepared into a barrel shape by sheet metal and welding processing, and connected to the magnetic field repulsion layer 211 by crimping, so as to wrap the sample chamber 100 after installation.

[0064] The infrared absorption layer 220 provided in the embodiments of the present application can be a hybrid coating of resin and semiconductor particles. The hybrid coating can be composed of a resin, semiconductor particles that absorb infrared photons, and a curing agent mixed in a ratio of 11:8:1. The mixed coating can then be sprayed onto the magnetic field shielding layer 210, for example, on the side of the magnetic field shielding layer 210 facing the sample chamber 100, on the side of the magnetic field shielding layer 210 facing away from the sample chamber 100, or between the magnetic field repulsion layer 211 and the high magnetic permeability layer 212. The specific selection depends on the actual application. The hybrid coating is cured after heat treatment (e.g., at 65 degrees Celsius). Alternatively, the resin can be epoxy resin, and the semiconductor particles can be 16-10,000 mesh silicon carbide particles. Silicon carbide is a wide-bandgap semiconductor with strong absorption of infrared photons in the infrared band. Silicon carbide of different particle sizes can absorb infrared photons of different wavelengths. The epoxy resin serves as a carrier and binder for the silicon carbide particles, and forms a stable composite absorbing structure after being subjected to high temperature and solidified, thereby effectively reducing infrared photon thermal noise in the sample chamber 100 in the refrigerator 10 .

[0065] Optionally, the thickness of the magnetic field shielding layer 210 provided in the embodiment of the present application is no greater than 2 mm. Considering the limited cooling capacity of the sample chamber 100 of the refrigerator 10, when the magnetic field shielding layer 210 provided in the embodiment of the present application includes a magnetic field repulsion layer 211 and a high magnetic permeability layer 212, the thickness of the magnetic field repulsion layer 211 can be 1 mm, and the thickness of the high magnetic permeability layer 212 can be 1 mm. This ensures that the magnetic field shielding layer 210 provided in the present application can be cooled by approximately 20 mK when the refrigerator 10 is in operation. Furthermore, the infrared absorption layer 220 provided in the embodiment of the present application can be a hybrid coating with a thickness in the micrometer range, and the specific thickness can be specifically designed based on the actual application.

[0066] refer to Figure 13FIG2 is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. The shielding cover 200 provided in the embodiment of the present application is a barrel-shaped shielding cover, comprising a connecting portion 201 extending beyond its opening. The refrigerator 10 comprises a mixing chamber cold plate 108 disposed opposite the sample chamber 100. The barrel-shaped shielding cover 200 encases the sample chamber 100 and is connected and fixed to the mixing chamber cold plate 108 via the connecting portion 201, thereby indirectly securing the shielding cover 200 to the sample chamber 100.

[0067] refer to Figure 14 FIG2 is a schematic diagram of the structure of another shielding cover provided in an embodiment of the present application. The connecting portion 201 provided in the embodiment of the present application is fixed to the mixing chamber cold plate 108 via screws 202. Furthermore, screw washers (not shown) may be provided at the screws 202 to securely connect the shielding cover 200 to the mixing chamber cold plate 108, thereby indirectly securing the shielding cover 200 to the sample chamber 100. Optionally, the screws 202 and screw washers provided in the embodiment of the present application may be made of titanium or an alloy including titanium to be suitable for use in extremely low-temperature environments. The selection of screws 202 and screw washers of the relevant materials should be based on the actual application, and this application does not impose any specific restrictions.

[0068] Based on the same inventive concept, the present application also provides a refrigerator. Figure 1 As shown, the refrigerator provided in the embodiment of the present application includes: a sample chamber 100; a shielding cover 200 arranged corresponding to the sample chamber 100, wherein the shielding cover is the shielding cover 200 for the refrigerator 10 provided in any one of the above embodiments, and the shielding cover 200 includes a magnetic field shielding layer 210 wrapping the sample chamber 100, and an infrared absorption layer 220 wrapping the sample chamber 100.

[0069] Continue as Figure 13 and 14 As shown, in the refrigerator 10, the refrigerator 10 includes a mixing chamber cold plate 108 disposed opposite the sample chamber 100. The shielding cover 200 provided in the embodiment of the present application may be a barrel-shaped shielding cover, and the barrel-shaped shielding cover 200 includes a connecting portion 201 extending outside its opening; wherein the barrel-shaped shielding cover 200 wraps the sample chamber 100 and is connected and fixed to the mixing chamber cold plate 108 via the connecting portion 201, thereby indirectly fixing the shielding cover 200 to the sample chamber 100. Optionally, the connecting portion 201 and the mixing chamber cold plate 108 are fixed by screws 202, and screw washers may be further provided at the screws 202 to connect and fix the shielding cover 200 to the mixing chamber cold plate 108, thereby indirectly tightly connecting and fixing the shielding cover 200 to the sample chamber 100.

[0070] In some embodiments, the refrigerator 10 provided in the embodiments of the present application may be a dilution refrigerator, or may be other suitable types of refrigerators, and the present application does not impose any specific limitation on this.

[0071] Based on the same inventive concept, embodiments of the present application further provide a quantum computer, comprising the refrigerator 10 provided in any of the above embodiments. Optionally, the quantum computer provided in embodiments of the present application may comprise a superconducting quantum computer (SQC), or may be another suitable type of quantum computer, which is not specifically limited in this application.

[0072] In summary, the embodiments of the present application provide a shielding cover for a refrigerator, a refrigerator, and a quantum computer, wherein the refrigerator includes a sample chamber; the shielding cover is arranged corresponding to the sample chamber, wherein the shielding cover includes a magnetic field shielding layer that wraps the sample chamber, and an infrared absorption layer that wraps the sample chamber. The technical solution provided in the embodiments of the present application arranges the shielding cover corresponding to the sample chamber, thereby improving the magnetic field noise experienced by the sample chamber by wrapping the magnetic field shielding layer of the sample chamber; and improving the thermal noise of infrared photons radiated from the refrigerator to the sample chamber by wrapping the infrared absorption layer of the sample chamber, thereby achieving the purpose of improving the influence of magnetic field noise and thermal noise experienced by the sample chamber, thereby providing a less noisy working environment for the quantum bits, quantum amplifiers, etc. of the quantum processor in the sample chamber, and improving the performance of the quantum computer.

[0073] In the description of the embodiments of the present application, it should be understood that the orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the embodiments of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise clearly specified.

[0075] In the embodiments of this application, unless otherwise specified or limited, terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections, indirect connections through an intermediate medium, and internal connections between two components or interactions between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0076] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0077] In the embodiments of the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A shielding cover for a refrigerator, the refrigerator comprising a sample chamber, characterized in that: The shielding cover is arranged corresponding to the sample chamber, wherein the shielding cover includes a magnetic field shielding layer wrapping the sample chamber and an infrared absorption layer wrapping the sample chamber.

2. The shielding cover for a refrigerator according to claim 1, characterized in that: The magnetic field shielding layer includes at least one of a magnetic field repelling layer wrapping the sample chamber and a high magnetic permeability layer wrapping the sample chamber, and the magnetic permeability of the high magnetic permeability layer is greater than 100 kH / m; Wherein, when the magnetic field shielding layer includes the magnetic field repulsion layer and the high magnetic permeability layer, the magnetic field repulsion layer is located on the side of the high magnetic permeability layer facing the sample chamber, or the magnetic field repulsion layer is located on the side of the high magnetic permeability layer facing away from the sample chamber.

3. The shielding cover for a refrigerator according to claim 2, characterized in that: The infrared absorption layer is located on a side of the magnetic field shielding layer facing the sample chamber; Alternatively, the infrared absorption layer is located on the side of the magnetic field shielding layer facing away from the sample chamber; Alternatively, when the magnetic field shielding layer includes the magnetic field repelling layer and the high magnetic permeability layer, the infrared absorbing layer is located between the magnetic field repelling layer and the high magnetic permeability layer.

4. The shielding cover for a refrigerator according to claim 2, characterized in that: The magnetic field repelling layer is a superconductor layer.

5. The shielding cover for a refrigerator according to claim 2, characterized in that: The high magnetic permeability layer is a Permalloy layer or an Iron-Chromium-Cobalt alloy layer.

6. The shielding cover for a refrigerator according to claim 1, characterized in that: The thickness of the magnetic field shielding layer is no more than 2 mm.

7. The shielding cover for a refrigerator according to claim 1, characterized in that: The infrared absorption layer is a mixed coating of resin and semiconductor particles.

8. The shielding cover for a refrigerator according to claim 1, characterized in that: The shielding cover is a barrel-shaped shielding cover, and the barrel-shaped shielding cover includes a connecting portion extending out of its opening; The refrigerator comprises a mixing chamber cold plate arranged opposite to the sample chamber, the barrel-shaped shielding cover wraps the sample chamber, and is fixedly connected to the mixing chamber cold plate via the connecting portion.

9. The shielding cover for a refrigerator according to claim 8, characterized in that: The connecting portion is fixed to the mixing chamber cold plate by screws.

10. The shielding cover for a refrigerator according to claim 3, characterized in that: When the magnetic field shielding layer includes one of the magnetic field repelling layer and the high magnetic permeability layer, the one of the magnetic field repelling layer and the high magnetic permeability layer is provided without a gap with the infrared absorbing layer; or When the magnetic field shielding layer includes the magnetic field repelling layer and the high magnetic permeability layer, any two adjacent layers among the magnetic field repelling layer, the high magnetic permeability layer and the infrared absorbing layer are arranged without a gap.

11. A refrigerator, characterized in that: The refrigerator comprises: Sample room; A shielding cover is provided corresponding to the sample chamber, wherein the shielding cover is the shielding cover for a refrigerator according to any one of claims 1 to 10.

12. The refrigerator according to claim 11, characterized in that The refrigerator comprises a dilution refrigerator.

13. The refrigerator according to claim 11, wherein The refrigerator includes a mixing chamber cold plate disposed opposite to the sample chamber; The shielding cover is a barrel-shaped shielding cover, and the barrel-shaped shielding cover includes a connecting portion extending out of its opening; the barrel-shaped shielding cover wraps the sample chamber and is connected and fixed to the mixing chamber cold plate through the connecting portion.

14. A quantum computer, characterized in that The quantum computer comprises the refrigerator according to any one of claims 11 to 13.

15. The quantum computer according to claim 14, characterized in that The quantum computer includes a superconducting quantum computer.

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