Superconducting quantum interference device based on current locking mode and preparation method thereof

Abstract

The invention relates to a superconducting quantum interference device based on a current locking mode and a preparation method thereof, and the device comprises an SQUID coil which comprises a fourth inductor; the bias coil is coupled with the SQUID coil, and a bias end is formed on the superconducting quantum interference device based on the current locking mode; the second-stage magnetic flux conversion coil is provided with a second inductor and a third inductor, and the third inductor is coupled with the fourth inductor; the input coil is provided with a first inductor and a fifth inductor, the first inductor is coupled with the second inductor, and an input end is formed on the superconducting quantum interference device; and the current locking feedback coil forms a sixth inductor, the sixth inductor is coupled with the fifth inductor, and a current locking feedback end is formed on the superconducting quantum interference device. The influence of environmental noise can be eliminated to the greatest extent at least through a plurality of coils, and the influence of the environmental noise on the position of the SQUID working point is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of superconducting electronics, and in particular to a superconducting quantum interference device based on a current locking mode and a preparation method thereof. Background Art

[0002] The superconducting quantum interference device (SQUID) is the most sensitive magnetic field sensor currently. Its equivalent energy resolution is close to the quantum limit level and is widely used in the low-temperature amplification of single-photon and monoenergetic ray detection. The current sensor based on SQUID can accurately measure tiny currents and other signals that can be equivalently converted into magnetic flux. It is the only readout device for instruments such as superconducting transition edge sensor (TES), metal magnetic calorimeter (MMC), and cryogenic current comparator (CCC). Therefore, as a key core device of modern large-scale scientific devices in cosmology and biomedicine, the research on its preparation process, configuration design, principle theoretical simulation, and amplification readout technology is crucial.

[0003] The low-temperature SQUID needs to read the noise of the system temperature, so extremely high sensitivity is required. However, due to the influence of environmental noise, the low-temperature SQUID can never be at the initial working point, which has a great impact on the reading accuracy of the system temperature noise. Summary of the invention

[0004] Based on this, it is necessary to provide a superconducting quantum interference device based on current locking and a preparation method thereof to address the above-mentioned technical problems, which can at least eliminate the influence of environmental noise to the greatest extent through multiple coils, thereby avoiding the influence of environmental noise on the SQUID working point position.

[0005] In order to achieve the above-mentioned purpose and other purposes, in a first aspect, the present disclosure provides a superconducting quantum interference device based on a current locking method, including: a QUID coil, the SQUID coil includes a fourth inductor; a bias coil, coupled with the SQUID coil, and forming a bias end on the superconducting quantum interference device based on the current locking method; a secondary magnetic flux conversion coil, the secondary magnetic flux conversion coil is formed with a second inductor and a third inductor, and the third inductor is coupled with the fourth inductor; an input coil, the input coil is formed with a first inductor and a fifth inductor, the first inductor is coupled with the second inductor, and forms an input end on the superconducting quantum interference device; a current locking feedback coil, the current locking feedback coil is formed with a sixth inductor, the sixth inductor is coupled with the fifth inductor, and forms a current locking feedback end on the superconducting quantum interference device.

[0006] In the superconducting quantum interference device based on the current locking method in the above-mentioned embodiment, through the coupling feedback between the sixth coil of the current locking feedback coil and the fifth coil of the input coil, and through the multi-stage coil coupling of the first coil, the second coil, the third coil, and the fourth coil, the current feedback at the current feedback end is directly used to compensate for the input signal of the input coil, and the influence of environmental noise is eliminated through the coupling of the multi-stage coils, thereby avoiding the influence of environmental noise on the SQUID working point position.

[0007] In one embodiment, the input coil further includes a filter circuit, one end of the filter circuit is connected to the positive electrode of the input end, and the other end of the filter circuit is connected to the negative electrode of the input end.

[0008] In one embodiment, the filtering circuit includes a first resistor and a first capacitor, one end of the first resistor is connected to the positive electrode of the input end as one end of the filtering circuit, the other end of the first resistor is connected to one end of the first capacitor, and the other end of the capacitor is connected to the negative electrode of the input end as the other end of the filtering circuit.

[0009] In one embodiment, the superconducting quantum interference device based on the current locking method also includes a flux locking feedback coil, which forms a seventh inductor. The seventh inductor is coupled with the fourth inductor and forms a flux locking feedback end on the superconducting quantum interference device.

[0010] In one embodiment, the flux locking feedback coil enables the SQUID coil to operate at an initial operating point by compensating the magnetic flux.

[0011] In one embodiment, the current locking feedback coil is used to make the SQUID coil operate at an initial operating point by inputting a compensation current.

[0012] In one embodiment, it also includes a first low-pass filter, a second low-pass filter and a third low-pass filter; wherein, one end of the first low-pass filter is connected to the fourth inductor, the other end of the first low-pass filter is connected to the bias end, one end of the second low-pass filter is connected to the flux locking feedback end, the other end of the second low-pass filter is connected to the seventh inductor, one end of the third low-pass filter is connected to the current locking feedback end, and the other end of the second low-pass filter is connected to the sixth inductor.

[0013] In one embodiment, the SQUID coil includes four sub-SQUID loops, and the four sub-SQUID loops are connected in parallel and arranged in a central symmetrical manner.

[0014] In one embodiment, a superconducting quantum interference device based on current locking method includes: a substrate; a target superconducting layer, located on the substrate, the target superconducting layer includes a first superconducting layer, a first insulating layer and a second superconducting layer, the first superconducting layer is located on the substrate, the first insulating layer is located on the first superconducting layer, and the second superconducting layer is located on the first insulating layer; a second insulating layer, located on the second superconducting layer; a superconducting coil layer, located on the second insulating layer, used to form a SQUID coil, a bias coil, a secondary magnetic flux conversion coil, an input coil and a current locking feedback coil; a resistance layer, located on the superconducting coil layer.

[0015] In a second aspect, the embodiments of the present disclosure also provide a method for preparing a superconducting quantum interference device based on a current locking method, comprising: providing a substrate; forming a target superconducting layer on the substrate, the target superconducting layer comprising a first superconducting layer, a first insulating layer and a second superconducting layer, the first superconducting layer being located on the substrate, the first insulating layer being located on the first superconducting layer, and the second superconducting layer being located on the first insulating layer; forming a second insulating layer on the target superconducting layer; forming a superconducting coil layer on the second insulating layer, the superconducting coil layer being used to form a SQUID coil, a bias coil, a secondary magnetic flux conversion coil, an input coil and a current locking feedback coil; forming a superconducting coil on the superconducting layer ... A resistance layer is formed on the conductive coil layer; wherein the SQUID coil includes a fourth inductor, the bias coil is coupled with the SQUID coil, and forms a bias end on a superconducting quantum interference device based on a current locking method, the secondary magnetic flux conversion coil is formed with a second inductor and a third inductor, the third inductor is coupled with the fourth inductor, the input coil is formed with a first inductor and a fifth inductor, the first inductor is coupled with the second inductor, and forms an input end on the superconducting quantum interference device, and the current locking feedback coil is formed with a sixth inductor, the sixth inductor is coupled with the fifth inductor, and forms a current locking feedback end on the superconducting quantum interference device.

[0016] In the preparation method of the superconducting quantum interference device based on the current locking method in the above embodiment, the coupling feedback between the sixth coil of the current locking feedback coil and the fifth coil of the input coil is performed, and the multi-stage coil coupling of the first coil, the second coil, the third coil, and the fourth coil is performed, so that the current feedback at the current feedback end directly forms compensation for the input signal of the input coil, and the influence of environmental noise is eliminated through the coupling of the multi-stage coils, thereby avoiding the influence of environmental noise on the SQUID working point position. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic flow chart of a method for preparing a superconducting quantum interference device based on a current locking method provided in an embodiment;

[0019] Figure 2 It is a schematic diagram of the principle of a superconducting quantum interference device based on a current locking method provided in one embodiment;

[0020] Figure 3 It is a schematic diagram of the structure of a superconducting quantum interference device based on a current locking method provided in one embodiment.

[0021] Description of reference numerals:

[0022] 201, bias terminal; 202, secondary flux conversion coil; 203, input terminal; 204, current locking feedback coil; 205, flux locking feedback terminal; 206, filtering circuit; R, first resistor; C, first capacitor; L1, first inductor; L2, second inductor; L3, third inductor; L4, fourth inductor; L5, fifth inductor; L6, sixth inductor; L7, seventh inductor; 301, SQUID coil; 302, first low-pass filter; 303, second low-pass filter; 304, third low-pass filter. DETAILED DESCRIPTION

[0023] In order to facilitate understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0025] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. On the contrary, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer, doping type or portion discussed below may be represented as a second element, component, region, layer or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0026] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0027] When used herein, the singular forms "a", "an" and " / the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of features, integers, steps, operations, elements and / or components can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0028] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic representations of ideal embodiments (and intermediate structures) of the present disclosure, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Thus, embodiments of the present disclosure should not be limited to the particular shapes of the regions shown herein, but rather include deviations in shapes due to, for example, manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Thus, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shape of the region of the device, and do not limit the scope of the present disclosure.

[0029] Please refer to Figure 1-Figure 3 The present disclosure provides a method for preparing a superconducting quantum interference device based on a current locking method, comprising the following steps:

[0030] Step S1000: providing a substrate.

[0031] The substrate 201 includes a front layer structure 202 .

[0032] The substrate may be made of semiconductor material, insulating material, conductor material or any combination thereof. The substrate may be a single-layer structure or a multi-layer structure. For example, the substrate may be a silicon substrate, a silicon germanium substrate, a silicon germanium carbon substrate, a silicon carbide substrate, a gallium arsenide substrate, an indium arsenide substrate, an indium phosphide substrate or other III / V semiconductor substrates or II / VI semiconductor substrates. Alternatively, for example, the substrate may be a layered substrate including silicon / silicon carbide, silicon on insulator or silicon germanium on insulator. Therefore, the type of substrate should not limit the scope of protection of the present disclosure.

[0033] Step S2000: forming a target superconducting layer on a substrate.

[0034] The target superconducting layer includes a first superconducting layer, a first insulating layer and a second superconducting layer. The first superconducting layer is located on the substrate, the first insulating layer is located on the first superconducting layer, and the second superconducting layer is located on the first insulating layer.

[0035] Step S3000: forming a second insulating layer on the target superconducting layer.

[0036] Step S4000: forming a superconducting coil layer on the second insulating layer.

[0037] Step S5000: forming a resistance layer on the superconducting coil layer.

[0038] Among them, the SQUID coil 301 includes a fourth inductor L4, the bias coil is coupled to the SQUID coil 301, and forms a bias end 201 on the superconducting quantum interference device based on the current locking method, the secondary magnetic flux conversion coil 202 is formed with a second inductor L2 and a third inductor L3, the third inductor L3 is coupled with the fourth inductor L4, the input coil is formed with a first inductor L1 and a fifth inductor L5, the first inductor L1 is coupled with the second inductor L2, and forms an input end 203 on the superconducting quantum interference device, and the current locking feedback coil 204 is formed with a sixth inductor L6, the sixth inductor L6 is coupled with the fifth inductor L5, and forms a current locking feedback end on the superconducting quantum interference device.

[0039] Here, it should be noted that the substrate, the target superconducting layer, the second insulating layer, the superconducting coil layer, and the resistance layer are used to form a SQUID basic device including a SQUID coil 301. In addition to the SQUID coil 301, the SQUID basic device also includes structures such as a Josephson junction for forming a superconducting device. The SQUID coil 301 also includes coils with other functions such as a positive feedback coil and a negative feedback coil, which will not be repeated here.

[0040] In the above embodiment, through the coupling feedback between the sixth coil of the current locking feedback coil 204 and the fifth coil of the input coil, and through the multi-stage coil coupling of the first coil, the second coil, the third coil, and the fourth coil, the current feedback at the current feedback end is directly used to compensate for the input signal of the input coil, and the influence of environmental noise is eliminated through the coupling of the multi-stage coils, thereby avoiding the influence of environmental noise on the SQUID working point position.

[0041] Specifically, by applying precise feedback current, the SUQID coil can maintain the system in a specific working state to ensure signal stability and accuracy.

[0042] In the meantime, please continue to refer to Figure 3 In the present application, the input coil coupled to the SQUID coil 301 and the secondary magnetic flux conversion coil 202 are relatively independent, avoiding mutual interference between the coils. The central symmetry of the entire device is maintained, which greatly eliminates the interference of the environmental magnetic field.

[0043] The first inductor L1 may be 450nH-470nH.

[0044] As an example, the first inductor L1 may be 450 nH, 460 nH, 470 nH, etc.

[0045] The second inductor L2 may be 1300pH-1700pH.

[0046] As an example, the second inductance L2 may be 1300pH, 1400pH, 1500pH, 1600pH, 1700pH, and so on.

[0047] The third inductor L3 may be 1800pH-2200pH.

[0048] As an example, the third inductance L3 may be 1800pH, 1900pH, 2000pH, 2100pH, 2200pH, and so on.

[0049] The fourth inductor L4 may be 50pH-70pH.

[0050] As an example, the fourth inductor L4 may be 50pH, 60pH, 70pH, etc.

[0051] The fifth inductor L5 may be 22nH-24nH.

[0052] As an example, the fifth inductor L5 may be 22 nH, 23 nH, 24 nH, and so on.

[0053] The sixth inductor L6 may be 21nH-23nH.

[0054] As an example, the sixth inductor L6 may be 21 nH, 22 nH, 23 nH, and so on.

[0055] As an example, the mutual inductance value of the first inductor L1 and the second inductor L2 may be approximately 26 nH, the mutual inductance value of the third inductor L3 and the fourth inductor L4 may be approximately 100 pH, and the mutual inductance value of the fifth inductor L5 and the sixth inductor L6 may be approximately 19 nH.

[0056] Please continue to refer to Figure 2 In one embodiment, the input coil further includes a filtering circuit 206 .

[0057] Specifically, one end of the filter circuit 206 is connected to the positive electrode of the input end 203 , and the other end of the filter circuit 206 is connected to the negative electrode of the input end 203 .

[0058] Please continue to refer to Figure 2 In one embodiment, the filter circuit 206 includes a first resistor R and a first capacitor C.

[0059] Specifically, one end of the first resistor R is connected to the positive electrode of the input terminal 203 as one end of the filter circuit 206 , the other end of the first resistor R is connected to one end of the first capacitor C, and the other end of the capacitor is connected to the negative electrode of the input terminal 203 as the other end of the filter circuit 206 .

[0060] Please continue to refer to Figure 2 The superconducting quantum interference device based on current locking also includes a flux locking feedback coil.

[0061] Specifically, the flux locking feedback coil forms a seventh inductor L7, the seventh inductor L7 is coupled with the fourth inductor L4, and forms a flux locking feedback terminal 205 on the superconducting quantum interference device.

[0062] In this way, the superconducting quantum sensor proposed in the present application can eliminate the influence of environmental noise through the current locking feedback coil 204, and can also eliminate the influence of environmental noise through the flux locking feedback coil, providing multiple ways to adjust the working point position for the superconducting quantum sensor.

[0063] The flux locking feedback coil enables the SQUID coil 301 to work at the initial working point by compensating the magnetic flux.

[0064] The current locking feedback coil 204 is used to make the SQUID coil 301 work at the initial working point by inputting a compensation current.

[0065] Please refer to Figure 3 The superconducting quantum interference device based on the current locking method also includes a first low-pass filter 302, a second low-pass filter 303 and a third low-pass filter.

[0066] Among them, one end of the first low-pass filter 302 is connected to the fourth inductor L4, the other end of the first low-pass filter 302 is connected to the bias end 201, one end of the second low-pass filter 303 is connected to the flux locking feedback end 205, the other end of the second low-pass filter 303 is connected to the seventh inductor L7, one end of the third low-pass filter is connected to the current locking feedback end, and the other end of the second low-pass filter 303 is connected to the sixth inductor L6.

[0067] Here, in superconducting quantum sensors, low-pass filters are used to suppress high-frequency noise and ensure the integrity and accuracy of low-frequency signals. Superconducting quantum sensors are extremely sensitive to tiny signals, especially when reading quantum information, high-frequency noise may significantly interfere with the signal, so low-pass filters are needed to achieve accurate signal processing and data acquisition, so that superconducting quantum sensors can achieve high-sensitivity and high-precision measurements in complex environments.

[0068] Please continue to refer to Figure 3In one embodiment, the SQUID coil 301 includes four sub-SQUID loops, which are connected in parallel and arranged in a centrally symmetrical manner.

[0069] In one embodiment, a superconducting quantum interference device based on current locking includes: a substrate; a target superconducting layer located on the substrate, the target superconducting layer includes a first superconducting layer, a first insulating layer and a second superconducting layer, the first superconducting layer is located on the substrate, the first insulating layer is located on the first superconducting layer, and the second superconducting layer is located on the first insulating layer; a second insulating layer is located on the second superconducting layer; a superconducting coil layer is located on the second insulating layer, and is used to form a SQUID coil 301, a bias coil, a secondary magnetic flux conversion coil 202, an input coil and a current locking feedback coil 204. A resistance layer is located on the superconducting coil layer.

[0070] Specifically, the materials of the first superconducting layer, the second superconducting layer and the superconducting coil layer may be polycrystalline niobium (Nb) thin films.

[0071] As an example, magnetron sputtering can be used to deposit and etch corresponding patterns on a polycrystalline niobium (Nb) film (for example, positive plate + positive resist can be used).

[0072] Wherein, the thickness of the first superconducting layer can be 100nm~200nm.

[0073] As an example, the thickness of the first superconducting layer may be 100 nm, 130 nm, 155 nm, 180 nm or 200 nm, etc.

[0074] Wherein, the thickness of the second superconducting layer can be 100nm~200nm.

[0075] As an example, the thickness of the second superconducting layer may be 100 nm, 130 nm, 155 nm, 180 nm, or 200 nm, etc.

[0076] The thickness of the superconducting coil layer may be 390nm-410nm.

[0077] As an example, the thickness of the superconducting coil layer may be 390 nm, 395 nm, 400 nm, or 410 nm, etc.

[0078] Specifically, the material of the first insulating layer may be an aluminum oxide film.

[0079] As an example, an ion beam may be used to etch a corresponding pattern on the aluminum oxide film after anodization (for example, positive plate + positive resist may be used).

[0080] The thickness of the first insulating layer may be 8nm-16nm.

[0081] As an example, the thickness of the first insulating layer may be 8 nm, 10 nm, 12 nm, 15 nm, 16 nm, or the like.

[0082] Specifically, the material of the second insulating layer may be silicon dioxide.

[0083] As an example, the second insulating layer may be formed by depositing and etching a corresponding pattern using chemical vapor deposition (for example, negative plate + positive resist may be used).

[0084] The thickness of the second insulating layer may be 350nm-380nm.

[0085] As an example, the thickness of the second insulating layer may be 350 nm, 360 nm, 370 nm, 380 nm, etc.

[0086] Specifically, the material of the resistance layer may be a PdAu thin film.

[0087] As an example, the resistance layer may be formed by depositing and etching corresponding patterns using electron beam evaporation (for example, positive plate + positive resist may be used).

[0088] The thickness of the resistance layer may be 50nm-500nm.

[0089] As an example, the thickness of the resistive layer may be 50 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc.

[0090] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0091] Based on the same inventive concept, the disclosed embodiment also provides a method for preparing a superconducting quantum interference device based on a current locking mode, and obtains a superconducting quantum interference device based on a current locking mode. The implementation scheme for solving the problem provided by the superconducting quantum interference device based on a current locking mode is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more superconducting quantum interference device embodiments based on a current locking mode provided below can refer to the limitations of the preparation method of the superconducting quantum interference device based on a current locking mode in the above text, and will not be repeated here.

[0092] In some embodiments, please refer to Figure 2 or Figure 3 A superconducting quantum interference device based on current locking method includes: a SQUID coil 301, the SQUID coil 301 includes a fourth inductor L4; a bias coil, coupled with the SQUID coil 301, and forming a bias terminal 201 on the superconducting quantum interference device based on current locking method; a secondary magnetic flux conversion coil 202, the secondary magnetic flux conversion coil 202 is formed with a second inductor L2 and a third inductor L3, the third inductor L3 is coupled with the fourth inductor L4; an input coil, the input coil is formed with a first inductor L1 and a fifth inductor L5, the first inductor L1 is coupled with the second inductor L2, and forms an input terminal 203 on the superconducting quantum interference device; a current locking feedback coil 204, the current locking feedback coil 204 is formed with a sixth inductor L6, the sixth inductor L6 is coupled with the fifth inductor L5, and forms a current locking feedback terminal on the superconducting quantum interference device.

[0093] For example, please continue to refer to Figure 2 and Figure 3 The input coil further includes a filter circuit 206 , one end of the filter circuit 206 is connected to the positive electrode of the input terminal 203 , and the other end of the filter circuit 206 is connected to the negative electrode of the input terminal 203 .

[0094] For example, please continue to refer to Figure 2 and Figure 3 The filter circuit 206 includes a first resistor R and a first capacitor C. One end of the first resistor R is connected to the positive electrode of the input terminal 203 as one end of the filter circuit 206, the other end of the first resistor R is connected to one end of the first capacitor C, and the other end of the capacitor is connected to the negative electrode of the input terminal 203 as the other end of the filter circuit 206.

[0095] For example, please continue to refer to Figure 2 and Figure 3 The superconducting quantum interference device based on the current locking method also includes a flux locking feedback coil, which forms a seventh inductor L7. The seventh inductor L7 is coupled with the fourth inductor L4 and forms a flux locking feedback end 205 on the superconducting quantum interference device.

[0096] For example, please continue to refer to Figure 2 and Figure 3 The flux locking feedback coil makes the SQUID coil 301 work at the initial working point by compensating the magnetic flux.

[0097] For example, please continue to refer to Figure 2 and Figure 3 The current locking feedback coil 204 is used to make the SQUID coil 301 work at the initial working point by inputting a compensation current.

[0098] For example, please continue to refer to Figure 2 and Figure 3 , also includes a first low-pass filter 302, a second low-pass filter 303 and a third low-pass filter; wherein, one end of the first low-pass filter 302 is connected to the fourth inductor L4, the other end of the first low-pass filter 302 is connected to the bias end 201, one end of the second low-pass filter 303 is connected to the flux locking feedback end 205, the other end of the second low-pass filter 303 is connected to the seventh inductor L7, one end of the third low-pass filter 304 is connected to the current locking feedback end, and the other end of the second low-pass filter 303 is connected to the sixth inductor L6.

[0099] For example, please continue to refer to Figure 2 and Figure 3 The SQUID coil 301 includes four sub-SQUID loops, which are connected in parallel and arranged in a centrally symmetrical manner.

[0100] For example, please continue to refer to Figure 2 and Figure 3 , a superconducting quantum interference device based on current locking includes: a substrate; a target superconducting layer, located on the substrate, the target superconducting layer includes a first superconducting layer, a first insulating layer and a second superconducting layer, the first superconducting layer is located on the substrate, the first insulating layer is located on the first superconducting layer, and the second superconducting layer is located on the first insulating layer; a second insulating layer is located on the second superconducting layer; a superconducting coil layer, located on the second insulating layer, used to form a SQUID coil 301, a bias coil, a secondary magnetic flux conversion coil 202, an input coil and a current locking feedback coil 204; a resistance layer, located on the superconducting coil layer. A superconducting quantum interference device based on current locking and a preparation method thereof proposed in the present application can at least eliminate the influence of environmental noise to the greatest extent through multiple coils, and avoid the influence of environmental noise on the position of the SQUID working point.

[0101] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the attached claims.

Claims

1. A superconducting quantum interference device based on current locking method, characterized in that: The superconducting quantum interference device comprises: A SQUID coil, the SQUID coil comprising a fourth inductor; A bias coil is coupled to the SQUID coil and forms a bias end on the current-locked superconducting quantum interference device; A secondary magnetic flux conversion coil, wherein the secondary magnetic flux conversion coil is formed with a second inductor and a third inductor, and the third inductor is coupled with the fourth inductor; An input coil, wherein the input coil is formed with a first inductor and a fifth inductor, the first inductor is coupled with the second inductor and forms an input end on the superconducting quantum interference device; A current locking feedback coil is formed with a sixth inductor, the sixth inductor is coupled with the fifth inductor, and a current locking feedback terminal is formed on the superconducting quantum interference device.

2. The superconducting quantum interference device based on current locking method according to claim 1, characterized in that: The input coil further includes a filter circuit, one end of the filter circuit is connected to the positive electrode of the input end, and the other end of the filter circuit is connected to the negative electrode of the input end.

3. The superconducting quantum interference device based on current locking method according to claim 2, characterized in that: The filter circuit includes a first resistor and a first capacitor, one end of the first resistor is connected to the positive electrode of the input end as one end of the filter circuit, the other end of the first resistor is connected to one end of the first capacitor, and the other end of the capacitor is connected to the negative electrode of the input end as the other end of the filter circuit.

4. The superconducting quantum interference device based on current locking method according to claim 1, characterized in that: The superconducting quantum interference device also includes a flux locking feedback coil, which forms a seventh inductor. The seventh inductor is coupled with the fourth inductor and forms a flux locking feedback end on the superconducting quantum interference device.

5. The superconducting quantum interference device based on current locking method according to claim 1 or 4, characterized in that: The flux locking feedback coil enables the SQUID coil to operate at an initial operating point by compensating the magnetic flux.

6. The superconducting quantum interference device based on current locking method according to claim 1 or 4, characterized in that: The current locking feedback coil is used to make the SQUID coil work at an initial working point by inputting a compensation current.

7. The superconducting quantum interference device based on current locking method according to claim 1, characterized in that: Also comprising a first low pass filter, a second low pass filter and a third low pass filter; Among them, one end of the first low-pass filter is connected to the fourth inductor, the other end of the first low-pass filter is connected to the bias end, one end of the second low-pass filter is connected to the flux locking feedback end, the other end of the second low-pass filter is connected to the seventh inductor, one end of the third low-pass filter is connected to the current locking feedback end, and the other end of the second low-pass filter is connected to the sixth inductor.

8. The superconducting quantum interference device based on current locking method according to claim 1, characterized in that: The SQUID coil comprises four sub-SQUID loops, which are connected in parallel and arranged in a central symmetric manner.

9. The superconducting quantum interference device based on current locking method according to claim 1, characterized in that: The superconducting quantum interference device comprises: substrate; a target superconducting layer, located on the substrate, the target superconducting layer comprising a first superconducting layer, a first insulating layer, and a second superconducting layer, the first superconducting layer being located on the substrate, the first insulating layer being located on the first superconducting layer, and the second superconducting layer being located on the first insulating layer; a second insulating layer, located on the second superconducting layer; A superconducting coil layer, located on the second insulating layer, used to form a SQUID coil, a bias coil, a secondary magnetic flux conversion coil, an input coil and a current locking feedback coil; The resistance layer is located on the superconducting coil layer.

10. A method for preparing a superconducting quantum interference device based on a current locking method, characterized in that: include: providing a substrate; forming a target superconducting layer on the substrate, the target superconducting layer comprising a first superconducting layer, a first insulating layer, and a second superconducting layer, wherein the first superconducting layer is located on the substrate, the first insulating layer is located on the first superconducting layer, and the second superconducting layer is located on the first insulating layer; forming a second insulating layer on the target superconducting layer; forming a superconducting coil layer on the second insulating layer, wherein the superconducting coil layer is used to form a SQUID coil, a bias coil, a secondary magnetic flux conversion coil, an input coil and a current locking feedback coil; forming a resistance layer on the superconducting coil layer; Among them, the SQUID coil includes a fourth inductor, the bias coil is coupled with the SQUID coil, and forms a bias end on the superconducting quantum interference device based on the current locking method, the secondary magnetic flux conversion coil forms a second inductor and a third inductor, the third inductor is coupled with the fourth inductor, the input coil forms a first inductor and a fifth inductor, the first inductor is coupled with the second inductor, and forms an input end on the superconducting quantum interference device, the current locking feedback coil forms a sixth inductor, the sixth inductor is coupled with the fifth inductor, and forms a current locking feedback end on the superconducting quantum interference device.

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