A thermal switch device and system for dilution refrigerator

Abstract

The application relates to a heat switch device and system for a dilution refrigerator, which is applied to the technical field of low-temperature equipment and comprises a shell and a stretching piece arranged in the shell, a piezoelectric ceramic stack is arranged in the stretching piece, the stretching piece is used for amplifying the stretching distance of the piezoelectric ceramic stack, a first heat sink is arranged between the shell and the stretching piece, and the first heat sink and the stretching piece are connected with two adjacent cold plates respectively. The piezoelectric ceramic stack is electrified, the piezoelectric ceramic stack is stretched along the length direction of the shell, the stretching piece is stretched along the length direction, the stretching distance of the length direction is amplified several times to stretch in the width direction, the stretching piece is in contact with the first heat sink, heat conduction between the stretching piece and the first heat sink is facilitated, the two adjacent cold plates are in heat conduction through the stretching piece and the first heat sink, and heat transfer between different temperature zones of the dilution refrigerator is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of cryogenic equipment, and in particular to a thermal switch device and system for a dilution refrigerator. Background Art

[0002] The fundamental unit of quantum computing is the quantum processor, which must operate in an ultra-low temperature environment of approximately 20 millikelvins (mK). This low temperature effectively reduces the impact of ambient noise on the superconducting quantum processor, achieving superior performance. However, if the operating temperature is too high, the evolution of its quantum state becomes extremely difficult to control. Currently, a dilution refrigerator is commonly used to provide this ultra-low temperature environment. This refrigerator employs a graded refrigeration technique to create different temperature zones. The quantum processor is typically placed in the dilution refrigerator's lowest temperature zone, while the signal source equipment and microwave detection equipment that control the quantum processor are typically located outside the dilution refrigerator.

[0003] Different temperature zones in a dilution refrigerator are separated by cold plates, effectively reducing interference in heat transfer between them. However, when the quantum processor needs to be removed, all temperature zones of the dilution refrigerator must be restored to room temperature. Currently, a common method is to connect two adjacent cold plates using an air-gap thermal switch. Under normal conditions, the air-gap thermal switch is in a vacuum state, preventing heat transfer between adjacent cold plates. However, when air is introduced into the air-gap thermal switch, heat is transferred from the two adjacent cold plates through the gas inside the air-gap thermal switch and its internal thermal fins, thereby achieving heat transfer between the different temperature zones in the dilution refrigerator.

[0004] Regarding the above-mentioned related technologies, the inventors believe that the heat-conducting fins of the air-gap thermal switch cross each other, requiring a distance close enough but not touching, which places great demands on the processing technology, resulting in complex and high-cost production and a small scope of application. Summary of the Invention

[0005] In order to improve the problem that the heat-conducting fins of the air-gap thermal switch cross each other, the distance is required to be close enough but not touching, which places great demands on the processing technology, has high production costs and a small scope of application. The present application provides a thermal switch device and system for a dilution refrigerator.

[0006] In a first aspect, the present application provides a thermal switch device for a dilution refrigerator using the following technical solution:

[0007] It includes a shell and a stretching member arranged in the shell, a first heat sink is arranged between the shell and the stretching member, a piezoelectric ceramic stack is arranged in the stretching member, the stretching member is used to amplify the stretching distance of the piezoelectric ceramic stack so that the stretching member conflicts with the first heat sink, and the first heat sink is connected to two adjacent cold plates.

[0008] Optionally, the stretching member includes a fixed plate, a flexible rod and a stretching rod, and two fixed plates are provided along the length direction of the shell, one of the fixed plates is fixedly provided on the inner wall of the shell and connected to the cold plate;

[0009] The flexible rods are provided in two pairs, and the two pairs of flexible rods are both provided on opposite side walls of the two fixing plates, and the flexible rods of the same pair are provided along the length direction of the fixing plates;

[0010] The stretching rod corresponds to the flexible rod one by one, and the stretching rod is fixedly arranged at one end of the flexible rod away from the fixing plate.

[0011] Optionally, ends of the flexible rods of the same pair away from the fixing plate are close to each other, and ends of the two stretching rods of the same pair of flexible rods away from the flexible rods are close to each other.

[0012] Optionally, the stretching member further includes a fixing frame, which is fixedly mounted on a fixing plate, has a one-to-one correspondence with the fixing plates, and is disposed on opposite sides of two fixing plates, and the piezoelectric ceramic stack is fixedly mounted on the two fixing frames.

[0013] Optionally, a second heat sink is provided between two stretching rods arranged along the length direction of the shell, and the second heat sink is connected to the stretching rod via a connecting rod.

[0014] Optionally, the first heat sink and the second heat sink are made of high thermal conductivity materials.

[0015] Optionally, the surfaces of the first heat sink and the second heat sink are gold-plated.

[0016] Optionally, the housing is made of a low thermal conductivity material.

[0017] In a second aspect, the present application provides a dilution refrigerator, comprising a plurality of cold plates and the above-mentioned thermal switch device, wherein the thermal switch device is arranged between two adjacent cold plates.

[0018] In a third aspect, the present application provides a quantum computer comprising the above-mentioned dilution refrigerator and a quantum processor, wherein the quantum processor is disposed at the bottom layer of the dilution refrigerator.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: when the piezoelectric ceramic stack is energized, the piezoelectric ceramic stack is stretched along the length direction of the shell, so that the stretched part is stretched along the length direction, and the stretching part amplifies the stretching distance in the length direction by several times and stretches it in the width direction, so that the stretched part comes into contact with the first heat sink, thereby facilitating heat conduction between the stretching part and the first heat sink, and then facilitating heat conduction between the two adjacent cold plates through the stretching part and the first heat sink, so as to realize heat transfer between different temperature zones of the dilution refrigerator. At the same time, the present application does not require the use of complex processes such as cross-heat-conducting fins, and the stretching part can also be formed as one piece. It is only necessary to fix the piezoelectric ceramic stack in the stretching part. The processing technology is relatively simple, which greatly reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of a thermal switch device for a dilution refrigerator according to an embodiment of the present application.

[0021] Figure 2 It is a schematic structural diagram of a tensile member used in an embodiment of the present application.

[0022] Explanation of the accompanying drawings: 1. Housing; 2. Tensile member; 21. Fixing plate; 22. Flexible rod; 23. Tensile rod; 24. Fixing frame; 25. Second heat sink; 26. Connecting rod; 3. Piezoelectric ceramic stack; 4. First heat sink. DETAILED DESCRIPTION

[0023] The following is combined with Figures 1-2 This application is described in further detail.

[0024] The following detailed description is illustrative only and is not intended to limit the application or uses of the embodiments and / or embodiments. In addition, there is no intention to be bound by any express or implied information presented in the previous "Background Technology" or "Summary of the Invention" section or "Detailed Description of the Invention" section.

[0025] To make the purpose, technical solutions, and advantages of the embodiments of the present application clearer, one or more embodiments are now described with reference to the accompanying drawings, wherein similar reference numerals are used throughout the text to refer to similar components. In the following description, for the purpose of explanation, many specific details are set forth in order to provide a more thorough understanding of one or more embodiments. However, it is obvious that in various cases, one or more embodiments can be practiced without these specific details, and the various embodiments can be combined and referenced with each other without contradiction.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] An embodiment of the present application discloses a thermal switch device for a dilution refrigerator.

[0028] Reference Figure 1 and Figure 2 The thermal switch device includes a shell 1 and a tensile member 2 arranged in the shell 1, a piezoelectric ceramic stack 3 is arranged in the tensile member 2, a wire is fixed on the piezoelectric ceramic stack 3, and the tensile member 2 is used to amplify the stretching distance of the piezoelectric ceramic stack 3. A first heat sink 4 is arranged between the shell 1 and the tensile member 2, the first heat sink 4 is connected to one of the two adjacent cold plates, and the tensile member 2 is connected to the other of the two adjacent cold plates.

[0029] Reference Figure 1 and Figure 2 When power is applied to the piezoelectric ceramic stack 3 via a wire, it stretches along the length of the housing 1, causing the stretching element 2 to stretch in the lengthwise direction. The stretching element 2 then stretches in the widthwise direction, magnifying the lengthwise stretch distance several times. This brings the stretching element 2 into contact with the first heat sink 4, facilitating heat transfer between the two adjacent cold plates. This facilitates heat transfer between the different temperature zones of the dilution refrigerator. Furthermore, there is no need for complex structures such as cross-fins, and the stretching element 2 can be integrally formed, simplifying the manufacturing process and significantly reducing production costs.

[0030] Reference Figure 1 and Figure 2It should be understood that the piezoelectric ceramic stack 3 is composed of a plurality of piezoelectric ceramic chips stacked face to face and bonded with a special glue. Usually, the displacement of a single piezoelectric ceramic chip does not exceed 5μm, and the displacement of multiple piezoelectric ceramic chips can exceed 100μm after being stacked. In practice, when the piezoelectric ceramic stack 3 is energized, the piezoelectric ceramic stack 3 will produce a displacement of 40-200μm in the length direction. After being amplified by the tensile member 2, the tensile member 2 will produce a displacement of 1-3mm in the width direction, and a pressure of 10-100N can be applied to make the tensile member 2 press against the first heat sink 4. Before the piezoelectric ceramic stack 3 is energized, due to the gap between the first heat sink 4 and the tensile member 2 and the vacuum state, the thermal conductivity is extremely poor. It can be considered that no heat is transferred between the two adjacent cold plates.

[0031] Reference Figure 1 and Figure 2 The tensile member 2 includes a fixed plate 21, a fixed frame 24, a flexible rod 22, a tensile rod 23 and a second heat sink 25. Two fixed plates 21 are provided along the length direction of the housing 1, and one of the fixed plates 21 is fixedly provided on the inner wall of the housing 1. The fixed frame 24 is fixedly provided on the fixed plate 21, and the fixed frame 24 corresponds to the fixed plate 21 one by one, and the fixed frame 24 is provided on the opposite side of the two fixed plates 21. The piezoelectric ceramic stack 3 is fixedly provided on the two fixed frames 24. The flexible rods 22 are provided in two pairs, and the two pairs of flexible rods 22 are fixed on the opposite side walls of the two fixed plates 21. The flexible rods 22 of the same pair are provided along the length direction of the fixed plate 21. The tensile rods 23 correspond to the flexible rods 22 one by one, and the tensile rods 23 are fixedly provided at the end of the flexible rod 22 away from the fixed plate 21. The ends of the flexible rods 22 in the same pair, away from the fixed plate 21, are close to each other. The ends of the two stretching rods 23 in the same pair, away from the flexible rods 22, are close to each other. It should be understood that the flexible rods 22 are relatively soft and thin enough to deform with minimal force. Alternatively, the flexible rods 22 can be hinged to the fixed plate 21. A second heat sink 25 is disposed between the two stretching rods 23 along the length of the housing 1 and is fixedly connected to the stretching rods 23 via a connecting rod 26.

[0032] Reference Figure 1 and Figure 2When power is supplied to the pressure ceramic stack, the pressure ceramic stack stretches and drives the fixing plate 21, which is not fixed to the housing 1, to stretch along the length direction of the housing 1 through the fixing member. The fixing plate 21 drives the flexible rod 22 to rotate toward the side away from the piezoelectric ceramic stack 3. The flexible rod 22 drives the stretching rod 23 to rotate. The stretching rod 23 drives the second heat sink 25 to move toward the first heat sink 4, so that the first heat sink 4 contacts the second heat sink 25, thereby facilitating heat transfer between the first heat sink 4 and the second heat sink 25, and further facilitating heat transfer between the fixing plate 21 and the first heat sink 4, so that heat transfer between the two adjacent cold plates is facilitated through the fixing plate 21 and the first heat sink 4.

[0033] Reference Figure 1 and Figure 2 , the first heat sink 4 and the second heat sink 25 are made of high thermal conductivity materials. In the temperature range of 0-4K, materials with a thermal conductivity of more than 100 are considered to be high thermal conductivity materials. In this application, the shell 1 is made of stainless steel. In this application, the first heat sink 4 and the second heat sink 25 are made of high-purity oxygen-free copper. The high thermal conductivity material described in this application refers to the gold plating on the surface of the first heat sink 4 and the second heat sink 25. The gold plating is to reduce the oxidation of the surface of the first heat sink 4 and the second heat sink 25. The shell 1 is made of low thermal conductivity materials. In the temperature range of 0-4K, materials with a thermal conductivity between 10^(-1) and 10 to the power of 1 are considered to be low thermal conductivity materials. In this application, the shell 1 is made of stainless steel.

[0034] The working principle of the embodiment of the present application is as follows: when power is supplied to the piezoelectric ceramic stack 3 via a wire, the piezoelectric ceramic stack 3 stretches along the length of the housing 1, causing the piezoelectric ceramic stack to stretch and, through the fixing member, drive the fixing plate 21, which is not fixed to the housing 1, to stretch along the length of the housing 1. The fixing plate 21 drives the flexible rod 22 to rotate away from the piezoelectric ceramic stack 3. The flexible rod 22 drives the stretching rod 23 to rotate. The stretching rod 23 drives the second heat sink 25 toward the first heat sink 4, so that the first heat sink 4 and the second heat sink 25 contact each other, thereby facilitating thermal conductivity between the first heat sink 4 and the second heat sink 25. This facilitates thermal conductivity between the stretching member 2 and the first heat sink 4, and further facilitates thermal conductivity between two adjacent cold plates through the stretching member 2 and the first heat sink 4, thereby achieving heat transfer between different temperature zones of the dilution refrigerator. Without the need for complex structures such as cross-heat conducting fins, the stretching member 2 can be formed in one piece, resulting in a relatively simple processing process and significantly reducing manufacturing costs.

[0035] Based on the same technical concept, the present application also provides a dilution refrigerator, comprising a plurality of cold plates and the above-mentioned thermal switch device, wherein the thermal switch device is arranged between two adjacent cold plates and can transfer heat between the two adjacent cold plates when powered on.

[0036] Based on the same technical concept, the present application also provides a quantum computer, comprising the above-mentioned dilution refrigerator and a quantum processor, wherein the quantum processor is arranged at the bottom layer of the dilution refrigerator.

[0037] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A thermal switch device for a dilution refrigerator, characterized in that: include: A housing (1) and a stretching member (2) disposed in the housing (1); a first heat sink (4) is disposed between the housing (1) and the stretching member (2); a piezoelectric ceramic stack (3) is disposed in the stretching member (2); the stretching member (2) is used to amplify the stretching distance of the piezoelectric ceramic stack (3) so that the stretching member (2) and the first heat sink (4) collide with each other; the first heat sink (4) and the stretching member (2) are respectively connected to two adjacent cold plates of a dilution refrigerator; The stretching member (2) is provided with a second heat sink (25) along the length direction of the shell (1); Before the piezoelectric ceramic stack (3) is energized, a gap exists between the first heat sink (4) and the stretching member (2). When the piezoelectric ceramic stack (3) is energized, the piezoelectric ceramic stack (3) drives the stretching member (2) to stretch along the length direction of the housing (1), thereby driving the second heat sink (25) to move toward the first heat sink (4), so that the first heat sink (4) contacts the second heat sink (25).

2. A thermal switch device for a dilution refrigerator according to claim 1, characterized in that: The stretching member (2) comprises a fixed plate (21), a flexible rod (22) and a stretching rod (23); two fixed plates (21) are provided along the length direction of the shell (1); one of the fixed plates (21) is fixedly provided on the inner wall of the shell (1) and connected to the cold plate; Two pairs of flexible rods (22) are provided, and the two pairs of flexible rods (22) are both provided on opposite side walls of two fixed plates (21), and the flexible rods (22) of the same pair are provided along the length direction of the fixed plates (21); The stretching rod (23) corresponds to the flexible rod (22) one by one, and the stretching rod (23) is fixedly arranged at one end of the flexible rod (22) away from the fixed plate (21).

3. A thermal switch device for a dilution refrigerator according to claim 2, characterized in that: The ends of the flexible rods (22) of the same pair away from the fixed plate (21) are close to each other, and the ends of the two stretching rods (23) of the same pair of flexible rods (22) away from the flexible rods (22) are close to each other.

4. A thermal switch device for a dilution refrigerator according to claim 2, characterized in that: The stretching member (2) further includes a fixing frame (24), the fixing frame (24) being fixedly arranged on the fixing plate (21), the fixing frame (24) corresponding to the fixing plate (21) one-to-one, and the fixing frame (24) being arranged on opposite sides of the two fixing plates (21), and the piezoelectric ceramic stack (3) being fixedly arranged on the two fixing frames (24).

5. The thermal switch device for a dilution refrigerator according to claim 2, characterized in that: A second heat sink (25) is provided between two stretching rods (23) arranged along the length direction of the housing (1), and the second heat sink (25) is connected to the stretching rod (23) via a connecting rod (26).

6. The thermal switch device for a dilution refrigerator according to claim 5, characterized in that: The first heat sink (4) and the second heat sink (25) are made of high thermal conductivity material.

7. The thermal switch device for a dilution refrigerator according to claim 6, characterized in that: The surfaces of the first heat sink (4) and the second heat sink (25) are gold-plated.

8. The thermal switch device for a dilution refrigerator according to claim 1, characterized in that: The housing (1) is made of low thermal conductivity material.

9. A dilution refrigerator, characterized in that: The invention comprises a plurality of cold plates and the thermal switch device according to claims 1 to 8, wherein the thermal switch device is arranged between two adjacent cold plates.

10. A quantum computer, characterized in that: The invention comprises the dilution refrigerator according to claim 9 and a quantum processor, wherein the quantum processor is arranged at the bottom layer of the dilution refrigerator.

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