Shielding shell, amplifier device, dilution refrigerator and quantum computer

Abstract

The utility model discloses a shielding shell, an amplifier device, a dilution refrigerator and a quantum computer, and belongs to the field of quantum computing. The shielding shell comprises a base and a top cover which are detachably connected with each other. The base and the top cover jointly define a containing cavity communicated with each other, a first through hole and a second through hole. The hole wall of the first through hole is provided with a first adhesion layer. The first adhesion layer has first hardness, and the first hardness is smaller than the hardness of the base and is also smaller than the hardness of the top cover. According to the scheme, the parametric amplifier can work normally under the external magnetic field required by the quantum chip test.

Description

Technical Field

[0001] This application belongs to the field of quantum information, especially the field of quantum computing technology. In particular, this application relates to a shielding case, an amplifier device, a dilution refrigerator, and a quantum computer. Background Art

[0002] A quantum parametric amplifier is a device with a core structure similar to a "superconducting quantum interference device". Its extremely low noise at low temperatures makes it suitable to be one of the important devices in the superconducting quantum chip measurement and control system. The physical characteristics of the "superconducting quantum interference device" make it extremely sensitive to magnetic field changes in the test environment, which will directly affect the working effect of the amplifier. Summary of the Utility Model

[0003] The examples of this application provide a shielding case, an amplifier device, a dilution refrigerator, and a quantum computer. Among them, the shielding case can provide a good magnetic shielding effect, so that the parametric amplifier can avoid being negatively affected by magnetic signals in a working environment with magnetic signals, making the use of the dilution refrigerator and quantum computer based on it more flexible and less demanding.

[0004] The solution of the example of this application is implemented through the following content.

[0005] In a first aspect, this application discloses a shielding case, which includes: a base and a top cover that are detachably connected to each other;

[0006] The base and the top cover jointly define a receiving cavity, as well as a first through hole and a second through hole, and the first through hole, the receiving cavity, and the second through hole are arranged and communicated in sequence;

[0007] A first attachment layer is provided on the hole wall of the first through hole;

[0008] The first attachment layer has a first hardness, and the first hardness is less than the hardness of the base and also less than the hardness of the top cover.

[0009] According to some examples of this application, the base has a first contact surface, the top cover has a second contact surface, and the first contact surface and the second contact surface are respectively smooth;

[0010] When the base and the top cover are in a connected state, the first contact surface and the second contact surface are fitted in a face-to-face manner.

[0011] According to some examples of this application, the first contact surface is a stepped surface, and the second contact surface is a stepped surface.

[0012] According to some examples of this application, the first through hole is composed of a first main hole and a first auxiliary hole. The first main hole is provided on the base, and the first auxiliary hole is provided on the top cover;

[0013] Alternatively, the second through-hole is formed by combining a second main hole and a second auxiliary hole, the second main hole is provided on the base, and the second auxiliary hole is provided on the top cover.

[0014] According to some examples of the present application, a second adhesion layer is provided on the hole wall of the second through-hole, the second adhesion layer has a second hardness, and the second hardness is less than the hardness of the base and also less than the hardness of the top cover.

[0015] According to some examples of the present application, the base is provided with a first groove, the top cover is provided with a second groove, and the accommodating cavity is formed by combining the first groove and the second groove;

[0016] Or, the base is provided with a first groove, the top cover is provided with a second groove, the accommodating cavity is formed by combining the first groove and the second groove, the base is provided with a first transition groove, and along the direction from the first through-hole to the second through-hole, the first transition groove is located between the first through-hole and the accommodating groove;

[0017] Or, the base is provided with a first groove, the top cover is provided with a second groove, the accommodating cavity is formed by combining the first groove and the second groove, the base is provided with a first transition groove, and along the direction from the first through-hole to the second through-hole, the first transition groove is located between the first through-hole and the accommodating groove, and the first through-hole, the first transition groove, and the accommodating cavity are arranged in a stepped manner.

[0018] According to some examples of the present application, the base is provided with a second transition groove, and along the direction from the first through-hole to the second through-hole, the second transition groove is located between the second through-hole and the accommodating groove;

[0019] Or, the base is provided with a second transition groove, and along the direction from the first through-hole to the second through-hole, the second transition groove is located between the second through-hole and the accommodating groove, and the second through-hole, the second transition groove, and the accommodating cavity are arranged in a stepped manner.

[0020] According to some examples of the present application, the shielding case includes bolts, and the base and the top cover are detachably connected by bolts;

[0021] Or, the base and the top cover are respectively provided with threaded holes;

[0022] Or, one of the base and the top cover is provided with a straight through-hole through which the bolt passes and has no thread, and the other is provided with a threaded hole matching the bolt;

[0023] Or, the manufacturing materials of the base and the top cover are respectively made of permalloy, and the manufacturing materials of the first adhesion layer and the second adhesion layer are respectively made of tin or indium.

[0024] In a second aspect, the present application discloses an amplifier device, including:

[0025] A parametric amplifier; and a shielding case, where the parametric amplifier is installed in the accommodation cavity of the shielding case, and the input end of the parametric amplifier passes through the first through hole and contacts the first attachment layer, and the output end of the parametric amplifier passes through the second through hole and contacts the second attachment layer.

[0026] In a third aspect, the present application discloses a dilution refrigerator, which includes:

[0027] A cold plate; and

[0028] A shielding case and an amplifier device, where the shielding case and the amplifier device are installed on the cold plate.

[0029] In a fourth aspect, the present application discloses a quantum computer, which includes a dilution refrigerator.

[0030] The shielding case in the examples of the present application can be used to magnetically protect the parametric amplifier, so that the parametric amplifier is protected from the adverse effects of magnetic signals. At the same time, the shielding case can also enable the parametric amplifier (such as IMPA; it can also be other components sensitive to magnetic signals) to work normally under the external magnetic field required for quantum chip testing, and will not introduce thermal noise or signal perturbation.

[0031] Specifically, by providing a first attachment layer in the first through hole of the shielding case and a second attachment layer in the second through hole, and since the hardness of the two attachment layers is less than that of the shielding case, when the input cable and output cable of the parametric amplifier are led out from the corresponding through holes, they can be in close contact with the shielding case through the attachment layers, thereby reducing the wear of the cables and also reducing the occurrence of magnetic signals "penetrating" from the gaps, so as to obtain a good magnetic shielding effect. Description of the Drawings

[0032] For a clearer illustration, the following will briefly introduce the drawings required for the description.

[0033] Figure 1 It is a schematic structural diagram of the shielding case in the examples of the present application;

[0034] Figure 2 It is Figure 1 an exploded structural diagram of the shielding case shown;

[0035] Figure 3 It is Figure 1 a sectional structural diagram of the shielding case shown from one perspective;

[0036] Figure 4 It is Figure 1 a sectional structural diagram of the shielding case shown from another perspective;

[0037] Figure 5 Disclosed Figure 1Schematic structural diagram of the base in the shielding case shown;

[0038] Figure 6 Disclosed is Figure 1 Schematic structural diagram of the top cover in the shielding case shown;

[0039] Figure 7 Schematic structural diagram of a magnetic shielding structure in an example of the present application;

[0040] Figure 8 Is Figure 7 Exploded structural diagram of the magnetic shielding structure;

[0041] Figure 9 Disclosed is Figure 7 Schematic structural diagram of the cover plate in the magnetic shielding structure;

[0042] Figure 10 Disclosed is Figure 7 Schematic structural diagram of the cover body in the magnetic shielding structure;

[0043] Figure 11 Disclosed is Figure 7 Schematic structural diagram of the cooperation connection between the hanging plate in the magnetic shielding structure and the parametric amplifier encapsulated in another shielding case in an example of the present application.

[0044] Explanation of reference numerals:

[0045] 100 - shielding case; 101 - base; 102 - top cover;

[0046] 103 - first through hole; 1031 - first main hole; 1032 - first sub - hole;

[0047] 1011 - first transition groove; 1012 - second transition groove; 1013 - first groove; 1031b - second groove; 1011a - first transition cavity; 1012a - second transition cavity;

[0048] 105 - second through hole; 106 - accommodation cavity; 107 - step surface;

[0049] 10 - cover body; 11 - hole; 12 - third mounting hole; 50 - first cover body; 60 - second cover body;

[0050] 20 - cover plate; 21 - boss; 22 - first mounting groove; 23 - fourth mounting hole;

[0051] 30 - hanging plate; 31 - first mounting hole; 32 - second mounting hole;

[0052] 40 - parametric amplifier. Detailed implementation manners

[0053] Due to the non-linearity and controllability of inductors, superconducting Josephson junctions have become one of the core components of superconducting quantum circuits and are widely used in superconducting qubits and superconducting quantum interference devices (SQUIDs).

[0054] Based on the non-linear inductance characteristics of Josephson junctions, a Josephson parametric amplifier (JPA) converts the energy of the pump signal into the energy of the input signal under the action of a specific pump frequency, achieving sensitive amplification of weak input signals with noise approaching the quantum limit.

[0055] In a superconducting quantum computer, to improve the readout fidelity of superconducting qubit signals in a superconducting quantum chip, multi-stage signal amplifiers are selected to obtain a high signal-to-noise ratio. As the first-stage amplifier on the superconducting qubit readout line, the performance of the Josephson parametric amplifier (hereinafter referred to as the parametric amplifier) plays a crucial role in the readout fidelity. Moreover, the Josephson Parametric Amplifier (JPA) also features high gain and noise close to the quantum limit, making it a key device in current superconducting qubit practice.

[0056] The core components in a Josephson parametric amplifier include a Josephson junction and a capacitor. The Josephson junction provides non-linear inductance, enabling it to form a non-linear LC resonant circuit together with the capacitor. The capacitor can be implemented as a parallel-plate capacitor. The parallel-plate capacitor is formed on the surface of the substrate and has an upper plate, a lower plate, and a filling medium between the upper and lower plates.

[0057] Although the parametric amplifier has the above advantages, it is extremely sensitive to magnetic signals, that is, extremely sensitive to magnetic field changes. If in an environment with magnetic field changes, it has a great negative impact on the normal operation of the parametric amplifier.

[0058] To enable the parametric amplifier to be immune to magnetic signals, a structure for realizing magnetic shielding of the parametric amplifier is disclosed in the examples of this application.

[0059] That is to say, by increasing the shielding of the parametric amplifier against external magnetic fields, the influence of external magnetic field changes on the performance and indicators of the parametric amplifier is reduced.

[0060] Generally speaking, in the examples of this application, a high-permeability material can be selected to "wrap" outside the parametric amplifier. It is easily magnetized, and through its high-permeability characteristic, it "twists" the direction of magnetic induction lines into its own interior and sends them out along the internal magnetic conduction path, so very little magnetic flux penetrates into the interior (the accommodation cavity 106 mentioned later).

[0061] And thus, it can be known that the more layers the high-permeability material is wrapped with, the smaller the magnetic noise impact on the parametric amplifier. Correspondingly, according to different usage scenarios of the parametric amplifier, the number of wrapping layers can be adaptively increased or decreased.

[0062] Correspondingly, in an example of the present application, a shielding case 100 is disclosed. Refer to Figures 1 to 6 .

[0063] As Figure 1 shown, the shielding case 100 includes a base 101 and a top cover 102. And the base 101 and the top cover 102 are detachably connected to each other. Therefore, when the base 101 and the top cover 102 are separated / disassembled, they can be used to take out the corresponding devices installed, such as the aforementioned parametric amplifier; and when the two are connected, devices such as parametric amplifiers can be installed in the case.

[0064] As a way to realize the detachable connection between the base 101 and the top cover 102, the base 101 and the top cover 102 can be selected to be threadedly connected. Therefore, in some examples, the shielding case 100 further includes bolts, and the base 101 and the top cover 102 are detachably connected by the bolts.

[0065] Correspondingly, the base 101 and the top cover 102 are respectively provided with threaded holes (not marked in the figure). Or, one of the base 101 and the top cover 102 is provided with a straight through hole through which the bolt passes and is not provided with threads, and the other of them is provided with a threaded hole matching the bolt. Or, the two are connected by fasteners (such as iron hoops, etc.) / jigs.

[0066] In the shielding case 100, the base 101 and the top cover 102 jointly define a receiving cavity 106, as well as a first through hole 103 and a second through hole 105, and the first through hole 103, the receiving cavity 106, and the second through hole 105 are arranged in sequence and communicated. Refer to Figure 2 , Figure 3 and Figure 4 .

[0067] Then it can be known that the shielding case 100 in the example of the present application is a structure that can shield the device from magnetic noise and also allows signal "communication" between the device and external devices. That is, the transmission signal can be in a wired manner, and the cable passes through the through hole and is respectively connected to the device and the signal line or device at both ends.

[0068] When the device to be magnetically shielded is installed in the shielding case 100, the main body of the device is placed in the accommodation cavity 106. At the same time, the configuration structure of the cables for inputting and outputting signals of the device is designed through the aforementioned first through hole 103 and second through hole 105. For example, the device has an input cable and an output cable. Therefore, the input cable extends from the main body of the device and passes through the first through hole 103; correspondingly, the output cable extends from the main body of the device and passes through the second through hole 105. Vice versa, that is, the output cable extends from the main body of the device and passes through the first through hole 103; correspondingly, the input cable extends from the main body of the device and passes through the second through hole 105.

[0069] Specifically, a first attachment layer (not shown in the figure) is provided on the hole wall of the first through hole 103, and the first attachment layer has a first hardness. Further, the first hardness is less than the hardness of the base 101 and also less than the hardness of the top cover 102. In other words, the texture of the first attachment layer is softer than the texture of the top cover 102, and the texture of the first attachment layer is softer than the texture of the base 101.

[0070] Due to the configuration of the first attachment layer, when the output cable (which can also be the input cable) of the parametric amplifier passes through the first through hole 103, the output cable can be in close contact with the first attachment layer, thereby reducing the gap, and further avoiding the leakage of magnetic signals into the accommodation cavity 106 of the shielding case 100 from the gap.

[0071] Preferably, due to the existence of the first attachment layer, the output cable will not be in direct contact with and rub against the top cover 102 and the base 101. Also, because the texture of the first attachment layer is softer, the wear of the output cable is small and the service life is longer.

[0072] Similarly to the first attachment layer, the shielding case 100 may also include a second attachment layer (not shown in the figure). And this attachment layer is combined with the hole wall of the second through hole 105. The second attachment layer has a second hardness, and the second hardness is less than the hardness of the base 101 and also less than the hardness of the top cover 102.

[0073] The second attachment layer has an effect similar to that of the first attachment layer. To avoid repetition, no specific discussion will be made here.

[0074] The relative magnitudes of the hardnesses of the first attachment layer and the second attachment layer and the hardnesses of the top cover 102 and the base 101 can be achieved by selecting a soft material for the attachment layer and a hard material for the top cover 102 and the base 101. Or, it can be achieved by directly measuring the hardness, such as Brinell hardness, Rockwell hardness, Vickers hardness, Leeb hardness, etc.

[0075] Considering the foregoing discussion of the principle of magnetic shielding, the top cover 102 and the base 101 can be selected as hard magnetic conductive alloys such as permalloy (different models of permalloy such as 1J50, 1J85, etc. can be selected according to different magnetic field environments, or other types of shielding materials), and the second adhesion layer and the first adhesion layer can be selected as metals such as soft solder like tin indium (which can be replaced with various non-magnetic soft metal solders), etc. Using solder can facilitate the bonding of the adhesion layer to the hole walls of the first through hole 103 and the second through hole 105.

[0076] In addition, it should be noted that the manufacturing materials of the top cover 102 and the base 101 can be the same or different. Similarly, the manufacturing materials of the first adhesion layer and the second adhesion layer can be the same or different, and can be independent of whether the manufacturing materials of the top cover 102 and the base 101 are the same or different.

[0077] Furthermore, the thicknesses of the first adhesion layer and the second adhesion layer can be selected according to the diameters of the first through hole 103 and the second through hole 105. Or it can also be comprehensively considered by taking into account the wire diameters of the cables of the devices to be magnetically shielded in the usage scenario.

[0078] For example, considering that the cable may be a coaxial cable with a metal braided layer. Therefore, the cable can have a certain amount of compression. Correspondingly, the diameter of the through hole after the adhesion layer is provided on the hole wall can be slightly smaller than the wire diameter of the cable, so that when installed, the cable can be in closer contact with the adhesion layer.

[0079] Since the base 101 and the top cover 102 are separate structures and can be disassembled and assembled with each other, they can have contact surfaces. As described above, the gaps between the through holes and the cables can become channels for magnetic leakage. Therefore, in order to reduce the potential gaps and large gaps between the contact surfaces of the base 101 and the top cover 102, the contact surfaces of the two can be smoothed. Correspondingly, the base 101 has a first contact surface, the top cover 102 has a second contact surface, and the first contact surface and the second contact surface are smooth respectively. On this basis, when the base 101 and the top cover 102 are in a connected state, the first contact surface and the second contact surface are fitted in a face-to-face manner.

[0080] In addition, the outer surfaces of the top cover 102 and the base 101 can also preferably be smooth. By combining the smooth and flat connection interface and the good and tight fit, the shielding case 100 can form a better magnetic conduction path as a whole.

[0081] Similar to the reason for setting the adhesion layer in the through hole, soft materials can also be provided on the first contact surface and the second contact surface respectively, so as to further control the potential gaps between the base 101 and the top cover 102.

[0082] In addition to the above improvements to the contact surfaces, in some other examples, it can also be considered that the first contact surface is a stepped surface 107 and the second contact surface is also a stepped surface 107. Refer to Figure 7 . Compared with the face-to-face contact of a plane, the contact of the stepped surface 107 is more conducive to reducing the risk of magnetic leakage into the accommodation cavity 106 of the shielding shell 100.

[0083] Since the first through hole 103 and the second through hole 105 are mainly defined jointly by the base 101 and the top cover 102, in some examples, the through holes can be constructed with different structures according to different designs. For example, both the first through hole 103 and the second through hole 105 can be arranged on the base 101, or both can be arranged on the top cover 102, or one of them can be arranged on the base 101 and the other can be arranged on the top cover 102.

[0084] In the illustrated structure of the present application, the first through hole 103 is composed of a first main hole 1031 and a first sub-hole 1032. The first main hole 1031 is arranged on the base 101, and the first sub-hole 1032 is arranged on the top cover 102. The second through hole 105 is composed of a second main hole and a second sub-hole. The second main hole is arranged on the base 101, and the second sub-hole is arranged on the top cover 102. Refer to Figure 2 and Figure 3 .

[0085] In addition to designing the through holes, the accommodation cavity 106 of the shielding shell 100 can also be structurally designed. For example, the accommodation cavity 106 can be constructed on the base 101 or on the top cover 102. In the illustrated structure of the present application, the accommodation cavity 106 is mainly respectively on the base 101 and the top cover 102. Correspondingly, in the example, the base 101 is provided with a first groove 1013, and the top cover 102 is provided with a second groove 1031b. Therefore, the accommodation cavity 106 is composed of the first groove 1013 and the second groove 1031b. Combine and refer to Figure 3 、 Figure 5 and Figure 6 .

[0086] Furthermore, the first groove 1013 can have a greater depth, while the second groove 1031b can have a smaller depth; or they can have the same depth. Further still, since the first groove 1013 and the second groove 1031b are adapted to the shape of the device to be shielded, when the shape of the device to be shielded is irregular, the two grooves can also have the same irregular structure.

[0087] For example, the first groove 1013 is composed of a plurality of sub-grooves, and the second groove 1031b can also have the same structural design.

[0088] Alternatively, the base 101 is provided with a first transition groove 1011. Along the direction from the first through hole 103 to the second through hole 105, the first transition groove 1011 is located between the first through hole 103 and the receiving groove. The base 101 is provided with a second transition groove 1012. Along the direction from the first through hole 103 to the second through hole 105, the second transition groove 1012 is located between the second through hole 105 and the receiving groove.

[0089] At the first transition groove 1011, the top cover 102 and the base 101 can jointly define a first transition cavity 1011a. Correspondingly, at the second transition groove 1012, the top cover 102 and the base 101 can jointly define a second transition cavity 1012a.

[0090] On the basis of designing the transition grooves, in some examples, the structure can be further optimized. For example, the first through hole 103, the first transition groove 1011, and the receiving cavity 106 are arranged in a stepped manner, and the second through hole 105, the second transition groove 1012, and the receiving cavity 106 are arranged in a stepped manner.

[0091] On the basis of the above shielding case 100, an amplifier device is also disclosed in the present application. The amplifier device includes: a parametric amplifier; and the shielding case 100.

[0092] The parametric amplifier therein is installed in the receiving cavity 106 of the shielding case 100, and the input end of the parametric amplifier passes through the first through hole 103 and contacts the first attachment layer, and the output end of the parametric amplifier passes through the second through hole 105 and contacts the second attachment layer.

[0093] As Figure 7 and Figure 8 shown: Another magnetic shielding structure is disclosed in the embodiments of the present application, which can be used to install the above shielding case 100. Correspondingly, the parametric amplifier installed in the shielding case 100 is fixed in the shielding case 100. Therefore, in such a structure, the parametric amplifier can have the "wrapping" effect of double-layer magnetic shielding materials.

[0094] In the example, as Figure 7 and Figure 8 shown, the magnetic shielding structure includes a cover body 10 with one end open, a cover plate 20, and a hanging plate 30.

[0095] The hanging plate 30 can be detachably installed on the cover plate 20. Specifically, as Figure 8 and Figure 9 shown, the hanging plate 30 includes a horizontal plate and a vertical plate arranged vertically. A plurality of first mounting holes 31 are provided on the horizontal plate, and a plurality of first mounting grooves 22 as Figure 9 shown are provided on the cover plate 20.

[0096] The horizontal plate and the cover plate 20 are detachably connected by screws sequentially passing through the first mounting holes 31 of the horizontal plate and the first mounting grooves 22 of the cover plate 20. A plurality of second mounting holes 32 are provided on the vertical plate for detachably mounting the parametric amplifier 40 (including a shielding case, and the shape of the shielding case can be adjusted on the basis of the shielding case in Figure 1 ), as shown in Figure 8 and Figure 11 .

[0097] Among them, the cover plate 20 covers the open end of the housing 10 (the other end of the housing is closed); the hanging plate 30 is located inside the housing 10, and the parametric amplifier 40 is mounted on the hanging plate 30 (see Figure 11 ). As shown in Figure 8 , a through hole 11 is provided on the housing 10, and the through hole 11 is used to realize the electrical connection between the parametric amplifier 40 and the external devices of the housing 10. That is, the signal input and signal output cables of the parametric amplifier are introduced into the housing through this through hole, and led out of the housing to the outside of the housing.

[0098] In some embodiments of the present application, the installation method of the housing 10 and the cover plate 20 is as follows: the open end of the housing 10 extends outward to form an ear plate, and the ear plate is detachably mounted on the cover plate 20. Specifically, as shown in Figure 8 and Figure 9 , a third mounting hole 12 is provided on the ear plate, and a fourth mounting hole 23 is provided on the cover plate 20. Screws are sequentially passed through the third mounting hole 12 of the ear plate and the fourth mounting hole 23 of the cover plate 20 to realize the detachable connection between the housing 10 and the cover plate 20. Further, a boss 21 is provided on the surface of the cover plate 20 close to the housing 10, and the open end of the housing 10 is clamped on the boss 21. By providing the boss 21, the housing 10 is clamped on the boss 21, ensuring an interference tight connection between the housing 10 and the cover plate 20, ensuring the magnetic continuity of the entire magnetic shielding structure, ensuring a low magnetic resistance path for magnetic flux, reducing magnetic leakage, and thus achieving the best shielding effect.

[0099] In the magnetic shielding structure of the example of the present application, the parametric amplifier 40 is mounted on the hanging plate 30 inside the housing 10, so that the parametric amplifier 40 is located inside the housing 10, and then the cover plate 20 is covered on the open end of the housing 10, so that the parametric amplifier 40 is in a relatively sealed magnetic shielding structure, avoiding interference of external magnetic fields on the parametric amplifier inside the housing. And since the parametric amplifier is also mounted through the shielding case 100 (it can be known that the shielding case 100 is fixedly / detachably connected to the hanging plate), a double magnetic shielding effect can be achieved.

[0100] By providing the through-hole 11, an electrical connection is achieved between the parametric amplifier 40 and the devices outside the housing 10. As a result, the parametric amplifier 40 (such as IMPA, JPA, etc.) can operate properly under the external magnetic field required for superconducting quantum chip testing. At the same time, the magnetic shielding structure can also avoid introducing thermal noise and signal perturbation.

[0101] In the embodiments of the present application, the shape of the through-hole 11 can be arbitrarily selected and is not particularly limited, as long as it can accommodate the signal transmission cable of the parametric amplifier. For example, the through-hole is one of a U-shaped hole, a rectangular hole, a kidney-shaped hole, an oval, or a circular hole. Exemplarily, as Figure 8 shown, the through-hole 11 is a U-shaped hole. By setting the through-hole 11 as a U-shaped hole, both the installation convenience and the magnetic leakage characteristics in the actual use process are considered.

[0102] In addition, there can be one through-hole 11, so the input and output cables of the parametric amplifier share one hole as the channel for entering and leaving the housing. Or, there can be two through-holes 11, so the input cable of the parametric amplifier uses one of them as the channel for entering and leaving the housing, while the output cable uses the other one as the channel for entering and leaving the housing.

[0103] In terms of shape, the housing 10 can adopt any shape as long as it can achieve a magnetic shielding effect that meets the usage requirements. As an example, the shape of the housing includes but is not limited to a cylindrical shape, a prismatic shape, and a rectangular shape. A beneficial choice is that the housing 10 is cylindrical because the cylindrical magnetic shielding structure has a smooth surface and is easier to reflect magnetic flux lines than the rectangular magnetic shielding structure, thereby maximizing the low-resistance path of the magnetic flux and achieving a better magnetic shielding effect.

[0104] Based on the usage scenario of the magnetic shielding structure, the smaller the size of the magnetic shielding structure, the better the magnetic shielding effect. Because experiments and simulations have verified that: the farther the distance between the magnetic leakage point in the magnetic shielding structure and the parametric amplifier 40, the smaller the magnetic leakage amount, that is, the magnetic leakage amount decreases significantly as the distance increases.

[0105] Analyzing from the structure, the magnetic leakage points in the magnetic shielding structure of the example of the present application may mainly exist in two positions: one is at the position of the through-hole 11 of the housing 10, and the other is at the connection between the housing 10 and the cover plate 20; and the through-hole 11 is the main magnetic leakage point.

[0106] Therefore, factors such as the size of the through-hole 11 in the magnetic shielding structure, the size of the open end of the housing 10, and the position of the parametric amplifier 40 will all affect the magnetic leakage amount during use, thereby having a substantial impact on the magnetic shielding effect.

[0107] To improve the magnetic shielding effect, the ratio of the minimum distance between the through-hole 11 and the parametric amplifier 40 to the diameter of the through-hole 11 is greater than 5.

[0108] Exemplarily, when the through-hole 11 is a round hole, the ratio of the minimum distance between the round hole and the parametric amplifier 40 to the diameter of the round hole is greater than 5;

[0109] When the through-hole 11 is a U-shaped hole, the ratio of the minimum distance between the U-shaped hole and the parametric amplifier 40 to the diameter of the arc segment in the U-shaped hole is greater than 5.

[0110] Further, when the cover 10 is a cylindrical shape with one end open, the ratio of the length of the cover 10 to the opening diameter is greater than or equal to 4; the minimum distance between the parametric amplifier 40 and the open end of the cover 10 is greater than the opening diameter.

[0111] Through the above scheme configuration, it is possible to minimize the magnetic leakage as much as possible while ensuring the installation feasibility of the parametric amplifier 40, and improve the magnetic shielding effect.

[0112] The above mainly discusses the structural characteristics of the magnetic shielding structure. Next, the characteristics of its materials will be described.

[0113] In the example of the present application, the cover 10 and the cover plate 20 are made of magnetic shielding materials. From the perspective of use, the parametric amplifier 40 can be located in a dilution refrigerator. Therefore, it can be defined that the magnetic shielding material has the following important characteristics at an extremely low temperature of 10 to 100 mK:

[0114] 1) The magnetic shielding material should have a high magnetic permeability;

[0115] 2) A saturation magnetization intensity greater than the magnetic field intensity of the application environment;

[0116] 3) The larger the saturation magnetic flux density, the more capable of absorbing the external magnetic field, and the better the shielding effect;

[0117] 4) The lower the coercivity, the easier it is to reduce the residual magnetic intensity after shielding.

[0118] Therefore, preferably, the materials of the cover 10 and the cover plate 20 are made of permalloy. Further, the material of the cover plate 20 can also be a TU0 gold-plated part with better thermal conductivity at low temperatures. The low temperature herein refers to, for example, the low temperature in the working state of the superconducting quantum chip (such as the aforementioned 10 to 100 mK).

[0119] As another scheme to improve the magnetic shielding effect, in some embodiments of the present application, the magnetic shielding structure can also be considered to adopt a multi-layer nested design, that is, multiple covers 10 are provided. And this method is applicable to the use of the aforementioned shielding case 100.

[0120] When multiple enclosures 10 are nested layer by layer (coaxially arranged), the outermost enclosure 10 is mainly used to reduce the external magnetic field intensity of the working environment (usually with a higher saturation magnetization intensity), and the inner enclosures 10 are mainly used for weak magnetic shielding to ensure that the magnetic field can be reduced to the range where the parametric amplifier 40 can work normally. Exemplarily, as Figure 10 shown, the magnetic shielding structure includes a first enclosure 50 and a second enclosure 60 arranged coaxially. Through holes 11 are provided in both the first enclosure 50 and the second enclosure 60, and the parametric amplifier 40 is located inside the second enclosure 60.

[0121] In this Figure 10 structure shown, there is a spacing between the first enclosure 50 and the second enclosure 60, that is, the inner wall of the first enclosure 50 does not contact the outer wall of the second enclosure 60. In other examples, the two can also be in contact or other magnetic shielding materials can be filled in the spacing space - it can be a solid (powder, block, etc.) or a non-solid, etc.

[0122] Furthermore, an example also discloses a dilution refrigerator. It includes a cold plate; and a shielding shell 100, or an amplifier device, and the shielding shell 100 and the amplifier device are installed on the cold plate.

[0123] A quantum computer can be constructed based on this dilution refrigerator.

[0124] The embodiments described above by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as a limitation to the present application.

[0125] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, one or more embodiments are described above with reference to the accompanying drawings. Among them, similar reference numerals are used throughout the text to refer to similar components. In the above description, for the purpose of explanation, many specific details are set forth 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 cross-referenced with each other on the premise of not being contradictory.

[0126] 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 do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order different from those illustrated or described here.

[0127] In addition, the terms "comprise" and "include" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that comprises a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0128] The structure, features and effects of the present application have been described in detail based on the embodiments shown in the drawings above. The above are only the preferred embodiments of the present application, but the present application is not limited to the scope of implementation shown in the drawings. Any changes made in accordance with the concept of the present application, or equivalent embodiments modified into equivalent changes, should still be within the protection scope of the present application when they do not exceed the spirit covered by the description and the drawings.

Claims

1. A shielding shell, characterized in that: include: A base and a top cover detachably connected to each other; The base and the top cover jointly define a receiving cavity, a first through hole, and a second through hole, and the first through hole, the receiving cavity, and the second through hole are sequentially arranged and connected; A first adhesion layer is disposed on the hole wall of the first through hole; The first adhesive layer has a first hardness, and the first hardness is smaller than the hardness of the base and also smaller than the hardness of the top cover.

2. The shielding case according to claim 1, characterized in that: The base has a first contact surface, the top cover has a second contact surface, and the first contact surface and the second contact surface are smooth respectively; When the base and the top cover are in a connected state, the first contact surface and the second contact surface cooperate with each other in a face-to-face manner.

3. The shielding case according to claim 2, characterized in that: The first contact surface is a step surface, and the second contact surface is a step surface.

4. The shielding case according to claim 1, characterized in that The first through hole is formed by combining a first main hole and a first auxiliary hole, the first main hole is arranged on the base, and the first auxiliary hole is arranged on the top cover; And / or, the second through hole is formed by combining a second main hole and a second auxiliary hole, the second main hole is arranged on the base, and the second auxiliary hole is arranged on the top cover; And / or, a second adhesion layer is provided on the hole wall of the second through hole, and the second adhesion layer has a second hardness, and the second hardness is smaller than the hardness of the base and also smaller than the hardness of the top cover.

5. The shielding case according to claim 1, characterized in that The base is provided with a first groove, the top cover is provided with a second groove, and the accommodating cavity is composed of the first groove and the second groove; Alternatively, the base is provided with a first groove, the top cover is provided with a second groove, the accommodating cavity is formed by combining the first groove and the second groove, the base is provided with a first transition groove, and along the direction from the first through hole to the second through hole, the first transition groove is located between the first through hole and the accommodating groove; Alternatively, the base is provided with a first groove, the top cover is provided with a second groove, the accommodating cavity is composed of the first groove and the second groove, the base is provided with a first transition groove, and along the direction from the first through hole to the second through hole, the first transition groove is located between the first through hole and the accommodating groove, and the first through hole, the first transition groove and the accommodating cavity are distributed in a stepped manner.

6. The shielding case according to claim 1 or 5, characterized in that: The base is provided with a second transition groove, and along the direction from the first through hole to the second through hole, the second transition groove is located between the second through hole and the accommodating groove; Alternatively, the base is provided with a second transition groove, and along the direction from the first through hole to the second through hole, the second transition groove is located between the second through hole and the accommodating groove, and the second through hole, the second transition groove and the accommodating cavity are distributed in a stepped manner.

7. The shielding case according to claim 1, characterized in that The shielding shell includes bolts, and the base and the top cover are detachably connected by the bolts; Alternatively, the base and the top cover are respectively provided with threaded holes; Alternatively, one of the base and the top cover has a straight hole for the bolt to pass through and is not provided with a thread, and the other one thereof is provided with a threaded hole matching the bolt; Alternatively, the base and the top cover are made of Permalloy, and the first adhesion layer and the second adhesion layer are made of tin or indium.

8. An amplifier device, characterized in that: include: Parametric amplifier; as well as According to the shielding shell as described in any one of claims 1 to 7, the parametric amplifier is installed in the accommodating cavity of the shielding shell, and the input end of the parametric amplifier passes through the first through hole and contacts with the first adhesion layer, and the output end of the parametric amplifier passes through the second through hole and contacts with the second adhesion layer.

9. A dilution refrigerator, characterized in that: include: Cold cuts; as well as The shielding case according to any one of claims 1 to 7, or the amplifier device according to claim 8, wherein the shielding case and the amplifier device are mounted to the cold plate.

10. A quantum computer, characterized in that: Comprising the dilution refrigerator as claimed in claim 9.

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