Sample stage for reproducing alternating-current quantum resistance in liquid-helium-free refrigerating system

Abstract

The invention provides a sample table for reproducing alternating-current quantum resistance in a liquid-helium-free refrigerating system, and relates to the field of resistance measurement, and the sample table comprises a sample fixing plate and a coaxial line fixing plate; the sample fixing plate and the coaxial line fixing plate are insulating plates; the sample fixing plate is fixed above the coaxial line fixing plate; at least seven through holes are formed in the coaxial line fixing plate; an integrated conductive film layer is laid on the upper end surface, the lower end surface and the inner side wall of the through hole; the upper end face and the lower end face of the penetrating hole are annular faces located on the upper surface and the lower surface of the coaxial line fixing plate respectively. According to a clockwise or anticlockwise sequence, the seven through holes respectively correspond to the terminals of the alternating current quantum resistor; the conductive film layers of the seven through holes are sequentially connected in series through a first lead positioned in the coaxial line fixing plate; measuring needles with the same number as the through holes are fixed on the sample fixing plate; and the measuring needles vertically penetrate through the upper and lower end faces of the sample fixing plate and are coaxially arranged with the through holes in a one-to-one correspondence manner.

Description

Technical Field

[0001] This invention relates to the field of resistance measurement, and more particularly to a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system. Background Technology

[0002] Existing technologies for reproducing and detecting gallium arsenide-based AC quantum resistance typically suffer from the following drawbacks:

[0003] I. Existing gallium arsenide-based AC quantum resistance reproduction requires a temperature range below 1.7K; however, after using a coaxial cable, the large thermal leakage of the coaxial cable causes the temperature range of the liquid helium-free self-circulating system to exceed 2K.

[0004] Second, using a C-type copper coil to achieve single-point grounding of multiple coaxial cables is problematic due to space constraints and welding interference, resulting in a large redundant wire length that cannot simultaneously ensure interference-free coaxial protection. Furthermore, welding is inconvenient, with large solder joints that compromise the interference-free characteristics of the coaxial cables.

[0005] Third, using a single flexible coaxial line results in excessive heat leakage for liquid helium-free cryogenic systems, leading to an imbalance between structure and heat leakage. If a high-resistivity stainless steel cryogenic coaxial line is used, the measurement error exceeds 1%. If a low-resistivity copper core coaxial line is used, the minimum temperature exceeds 2K, preventing the AC quantum resistance sample from being quantized. Summary of the Invention

[0006] To address the technical problems existing in the prior art, the present invention aims to provide a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system, which enables the temperature of the liquid helium-free cryogenic system to meet the quantization conditions of gallium arsenide AC quantum resistance samples below 1.7K.

[0007] To achieve the above-mentioned objectives, the present invention provides a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system, comprising a sample fixing plate and a coaxial line fixing plate.

[0008] Both the sample fixing plate and the coaxial line fixing plate are insulating plates; and the sample fixing plate is fixed above the coaxial line fixing plate.

[0009] The coaxial cable fixing plate is provided with at least seven through holes;

[0010] The upper end face, lower end face, and inner sidewall of the perforation are covered with an integral conductive film layer; the upper end face and lower end face of the perforation are annular surfaces located on the upper and lower surfaces of the coaxial fixing plate, respectively.

[0011] In a clockwise or counterclockwise order, the seven perforations correspond to the current excitation positive terminal, upstream voltage measurement positive terminal, upstream voltage measurement negative terminal, modulation terminal, current excitation negative terminal, downstream voltage measurement positive terminal, and downstream voltage measurement negative terminal of the AC quantum resistor, respectively; and the conductive film layers of the seven perforations are connected in series sequentially through the first wire located inside the coaxial fixed plate.

[0012] The sample fixing plate is fixed with the same number of measuring needles as the number of perforations;

[0013] The measuring needles all pass vertically through the upper and lower end faces of the sample fixing plate and are coaxially arranged in correspondence with the perforations.

[0014] According to one technical solution of the present invention, it further includes at least seven dual-segment coaxial cables;

[0015] The dual-segment coaxial cable is composed of a medium-resistance coaxial cable and a low-resistance coaxial cable of a set length, electrically connected end to end.

[0016] The resistance of the medium-resistance coaxial cable is 2Ω / m to 8Ω / m; the resistance of the low-resistance coaxial cable is 0.3Ω / m to 0.5Ω / m.

[0017] Seven dual-segment coaxial cables are inserted one-to-one into the seven through holes at one end of the medium-resistance coaxial cable;

[0018] The outer conductor of the medium-resistance coaxial line extends out of or is flush with the upper end face of the corresponding perforation, and is electrically connected to the conductive film layer of the corresponding perforation.

[0019] The inner conductor of the medium-resistance coaxial line is electrically connected to the pin of the corresponding measuring needle.

[0020] According to one technical solution of the present invention, a grounding wire is also included;

[0021] The first conductor is grounded through the grounding wire.

[0022] According to one technical solution of the present invention, the number of measuring needles and the number of punctures are both 12;

[0023] All measuring probes are divided into four groups; the four groups of measuring probes are arranged in a centrally symmetrical manner with the central axis of the sample fixing plate as the axis of symmetry; and some measuring probes are packaged in TO-8.

[0024] All perforations are divided into four groups; the four groups of perforations are arranged in a centrally symmetrical manner with the central axis of the coaxial fixing plate as the axis of symmetry.

[0025] According to one technical solution of the present invention, it also includes a chassis;

[0026] A central support column is vertically fixed to one end face of the chassis;

[0027] The sample fixing plate and the coaxial fixing plate are coaxially fixed by the central support column.

[0028] According to one technical solution of the present invention, it further includes a measuring rod and a flange;

[0029] The measuring rod secures the chassis via the flange.

[0030] The flange is provided with four cable bundle holes; and the positions of the four cable bundle holes are corresponding one-to-one with the positions of the four sets of through holes.

[0031] The chassis is provided with through holes corresponding to the four cable bundle holes;

[0032] One end of each of the two coaxial cables is located in the measuring rod, and the other end passes out of the measuring rod and sequentially through the corresponding cable bundle holes and through holes.

[0033] According to one technical solution of the present invention, a cover plate is also included;

[0034] The cover plate is fixed above the sample fixing plate;

[0035] There is a space between the cover plate and the sample fixing plate that can accommodate an AC quantum resistor.

[0036] According to one technical solution of the present invention, the sample fixing plate, coaxial fixing plate, chassis, measuring rod, flange, reinforcing fixing column and cover plate are all made of at least one of polyetherketone and polyamide ester.

[0037] According to one technical solution of the present invention, the length of the medium-resistance coaxial line is 20-40cm.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] 1. The structure of the sample stage used to reproduce AC quantum resistance in a liquid helium-free refrigeration system facilitates the use of a two-segment coaxial cable, maintaining both low line resistance and sufficient thermal resistance. Ultimately, the temperature of the liquid helium-free cryogenic system meets the quantization conditions of gallium arsenide AC quantum resistance samples below 1.7K.

[0040] 2. Using a coaxial cable fixing plate as a single-point short-circuit support frame for dual-segment coaxial cables to replace the C-type copper coil, the solder joints are smaller and easier to weld when soldering with medium-resistance coaxial cables, resulting in higher symmetry of the coaxial cables; and the short length enables equidistant single-point grounding.

[0041] 3. The above-mentioned dual-segment coaxial cable configuration can achieve AC quantum resistance measurement accuracy on the order of 10E-6. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0043] Figure 1 The schematic diagram shows the structure of a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to an embodiment of the present invention (excluding the two-segment coaxial cable, flange and measuring rod);

[0044] Figure 2 The schematic diagram shows the structure of a sample stage (including a two-segment coaxial cable) for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to an embodiment of the present invention.

[0045] Figure 3 This schematic diagram illustrates a structure in a coaxial fixing plate according to an embodiment of the present invention, where a perforation is connected by a first wire.

[0046] Figure 4 The schematic diagram shows the structure of a sample stage (including a two-segment coaxial cable, a flange, and a measuring rod) for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to an embodiment of the present invention. Detailed Implementation

[0047] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0048] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims. Specific Implementation Method 1

[0050] like Figures 1-4 As shown, a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to the present invention includes a sample fixing plate 1 and a coaxial fixing plate 2.

[0051] Both sample fixing plate 1 and coaxial fixing plate 2 are insulating plates; and sample fixing plate 1 is fixed above coaxial fixing plate 2.

[0052] The coaxial cable fixing plate 2 is provided with at least seven through holes 3;

[0053] An integral conductive film layer is applied to the upper end face, lower end face, and inner sidewall of the perforation 3; the upper end face and lower end face of the perforation 3 are annular surfaces located on the upper and lower surfaces of the coaxial fixing plate 2, respectively.

[0054] In a clockwise or counterclockwise order, the seven perforations 3 correspond to the current excitation positive terminal, upstream voltage measurement positive terminal, upstream voltage measurement negative terminal, modulation terminal, current excitation negative terminal, downstream voltage measurement positive terminal, and downstream voltage measurement negative terminal of the AC quantum resistor, respectively; and the conductive film layers of the seven perforations 3 are connected in series in sequence through the first wire located inside the coaxial fixed plate 2.

[0055] The sample fixing plate 1 is fixed with the same number of measuring needles 4 as the perforations 3;

[0056] The measuring needles 4 pass vertically through the upper and lower end faces of the sample fixing plate 1 and are coaxially arranged in correspondence with the perforations 3.

[0057] In this embodiment, a four-terminal sample stage for reproducing AC quantum resistance in a helium-free refrigeration system is proposed for gallium arsenide AC quantum resistance samples and a liquid helium-free ultra-low temperature (operating temperature condition ≈1.6K) system.

[0058] like Figure 1 , 2 As shown in Figure 4, the sample fixing plate 1 serves as a simplified support plate, replacing the existing fixing plate consisting of a metal sample stage and a PCB board. A single insulating plate can support at least 7 (typically 12) pinholes for inserting and fixing the measuring pins 4.

[0059] like Figure 3 As shown, the through holes 3 (preferably 12) of the coaxial cable fixing plate 2 adopt a PCB through hole 3 design, with conductive film layers (metal copper-clad film) on the inner wall and end face. Figure 2 and 3As shown, the seven through-holes 3 correspond to the wiring method of the four-terminal resistance measurement method, namely, the positive terminal for current excitation, the positive terminal for upstream voltage measurement, the negative terminal for upstream voltage measurement (using differential measurement of upstream voltage), the modulation wire, the negative terminal for current excitation, the positive terminal for downstream voltage measurement, and the negative terminal for downstream voltage measurement (using differential measurement of downstream voltage). They are arranged in a counterclockwise / clockwise C-shaped sequence and connected in series with the first wire to achieve a short circuit connection. The above seven through-holes 3 are fixedly connected to the medium-resistance coaxial line (as the wiring method for the four-terminal resistance measurement method), which can effectively fix the seven coaxial line sheaths to prevent them from contacting each other. This allows the coaxial line fixing plate 2 to act as a support frame for single-point short circuit of equidistant coaxial line sheaths, replacing the existing C-type copper coil, and achieving functions such as ultra-small solder joints, easy soldering, high symmetry, short length, and equidistant single-point grounding.

[0060] The rigid outer sheath (outer conductor) of the aforementioned coaxial cable is exposed above the upper surface of the coaxial cable fixing plate 2. The inner conductor of the coaxial cable is electrically connected to the tail of the corresponding measuring needle 4 on the sample fixing plate 1. Therefore, the structure of the sample stage used to reproduce AC quantum resistance in a liquid helium-free refrigeration system facilitates the use of two coaxial cable sections. The lower section is selected with a slightly larger impedance, such as a 20cm-40cm copper-nickel alloy coaxial cable. The upper section is selected with a copper coaxial cable. By adjusting the lengths of the two sections, the temperature of the liquid helium-free cryogenic system can ultimately meet the operating conditions of less than 1.7K.

[0061] During AC quantum resistance measurement, the AC quantum resistor is fixed to the upper surface of the sample mounting plate 1, and the pins of the AC quantum resistor are electrically connected to the corresponding measuring probe 4 as needed. Then, the seven corresponding coaxial cables are connected to the appropriate current source, voltmeter, modulator, etc.

[0062] Both sample fixing plate 1 and coaxial fixing plate 2 are made of insulating material with low dielectric constant. The only metal materials on sample fixing plate 1 and coaxial fixing plate 2 are the sample base socket and the 12 measuring pins 4 on sample fixing plate 1. This significantly reduces parasitic capacitance loss (equivalent to AC time constant), reducing the AC time constant from 300ns to less than 10ns. Specific Implementation Method Two

[0064] This embodiment is a further explanation of embodiment one. In this embodiment, at least seven bi-segment coaxial cables are also included.

[0065] The dual-segment coaxial cable is composed of a medium-resistance coaxial line 5 of a set length and a low-resistance coaxial line 14 electrically connected end to end;

[0066] The line resistance of medium-resistance coaxial cable 5 is 2Ω / m to 8Ω / m; the line resistance of low-resistance coaxial cable 14 is 0.3Ω / m to 0.5Ω / m.

[0067] Seven dual-segment coaxial cables are inserted one-to-one into seven through holes 3 at one end of the medium-resistance coaxial cable 5;

[0068] The outer conductor of the medium-resistance coaxial line 5 extends out of or is flush with the upper end face of the corresponding through hole 3, and is electrically connected to the conductive film layer of the corresponding through hole 3.

[0069] The inner conductor of the medium-resistance coaxial line 5 is electrically connected to the pin of the corresponding measuring needle 4.

[0070] In this embodiment, the existing technology for measuring AC quantum resistance at four terminals uses seven double-segment coaxial cables. The insulation of the seven double-segment coaxial cables is short-circuited and grounded at a single point. The existing technology uses seven flexible coaxial cables with a C-type copper coil. However, the short-circuit welding point of the insulation disrupts the coaxial symmetry and affects the AC shielding performance. At the same time, the flexible coaxial cables are tangled together.

[0071] This embodiment uses a two-segment coaxial cable as the wiring for the four-terminal AC resistance measurement method.

[0072] The aforementioned dual-segment coaxial cable consists of a medium-resistance coaxial cable 5 and a low-resistance coaxial cable 14 of a predetermined length, electrically connected end to end. The medium-resistance coaxial cable 5 is a copper-nickel alloy coaxial cable, with a resistance of approximately 2 to 8 ohms per meter; the low-resistance coaxial cable 14 is a pure copper coaxial cable, with a resistance of approximately 0.5 ohms per meter; and the high-resistance coaxial cable is a stainless steel coaxial cable, with a resistance of more than 20 to 100 ohms per meter.

[0073] Seven two-segment coaxial cables are connected to corresponding current sources, voltmeters, modulators, etc., via a medium-resistance coaxial cable 5 on the side closer to the AC quantum resistance sample and a low-resistance coaxial cable 14 on the side farther from the AC quantum resistance sample. During AC quantum resistance measurement, the AC quantum resistance is fixed to the upper surface of the sample mounting plate 1, and its leads are electrically connected to the corresponding measuring probes 4 as needed. This connection is then made to the medium-resistance coaxial cable 5 of the seven two-segment coaxial cables.

[0074] When fixed, the outer conductor end face of the medium-resistance coaxial line 5 is flush with the upper end face of the through hole 3, and electrical connection can be achieved directly by micro-spot welding while maintaining good coaxial symmetry. Furthermore, the vertical direction of the medium-resistance coaxial line 5 and the through hole 3 can be as close as possible to the pins led out from the sample stage (corresponding in position and coaxially set) to reduce the connection length of the medium-resistance coaxial line 5, thereby reducing line resistance and thermal resistance.

[0075] An insulating sheath can also be installed on the outer sheath of the dual-segment coaxial cable to prevent entanglement and short circuits.

[0076] The above-mentioned composite cryogenic coaxial cable matching scheme using dual-segment coaxial cables achieves a performance better than 1×10⁻⁶. -6The system achieves order-of-magnitude accuracy in AC quantum resistance measurements. This ensures that the gallium arsenide-based AC quantum resistance operates with both ultra-low temperatures and low parasitic capacitance, enabling forward alignment of the sample. Specific Implementation Method 3

[0078] This embodiment is a further explanation of embodiment one or two. In this embodiment, a grounding wire 6 is also included.

[0079] The first conductor is grounded through grounding wire 6.

[0080] In this embodiment, the coaxial cable fixing plate 2 serves as a single-point grounding structure and device for the dual-segment coaxial cable, which can maximize the coaxial interference-free protection, reduce redundant circuits, and achieve single-point grounding. It also helps to significantly reduce parasitic capacitance loss, and the AC time constant is reduced from 300ns to less than 10ns. Specific Implementation Method Four

[0082] This embodiment is a further explanation of embodiment three. In this embodiment, the number of measuring needles 4 and the number of piercing holes 3 are both 12.

[0083] All measuring needles 4 are divided into four groups; the four groups of measuring needles 4 are arranged in a centrally symmetrical manner with the central axis of the sample fixing plate 1 as the axis of symmetry; and some measuring needles 4 are packaged in TO-8.

[0084] All perforations 3 are divided into four groups; the four groups of perforations 3 are arranged in a centrally symmetrical manner with the central axis of the coaxial fixing plate 2 as the axis of symmetry.

[0085] In this embodiment, the extra measuring needle 4 and / or the hole 3 can be used as a spare in case other measuring needles 4 and / or the hole 3 fail, need to be modified, or other measuring methods are adopted. Detailed Implementation Method Five

[0087] This embodiment is a further explanation of embodiment four. In this embodiment, chassis 7 is also included.

[0088] A central support column 8 is vertically fixed to one end face of the chassis 7;

[0089] The sample fixing plate 1 and the coaxial fixing plate 2 are coaxially fixed by the central support column 8.

[0090] In this embodiment, the central support column 8, the sample fixing plate 1, and the coaxial fixing plate 2 are all made of the same material to reduce parasitic capacitance loss. Specific Implementation Method Six

[0092] This embodiment is a further explanation of embodiment five. In this embodiment, a measuring rod 9 and a flange 10 are also included.

[0093] Measuring rod 9 fixes base plate 7 via flange 10;

[0094] The flange 10 is provided with four cable bundle holes 11; and the positions of the four cable bundle holes 11 and the four sets of through holes 3 are respectively set one-to-one.

[0095] The chassis 7 is provided with through holes corresponding to the four cable bundle holes 11;

[0096] One end of each of the two coaxial cables is located in the measuring rod 9, and the other end passes out of the measuring rod 9 and sequentially through the corresponding cable bundle hole 11 and through hole.

[0097] In this embodiment, the length of the two-segment coaxial cable can be reduced by passing it through the nearest via.

[0098] Furthermore, it ensures that the seven double-section coaxial flanges 10 enter the central tube of the measuring rod 9, so that when performing AC quantum resistance testing, the device and the AC quantum resistor can be completely sealed within the test shield (which is the same as the shield for existing AC resistance testing and is not within the scope of protection of this invention).

[0099] Simultaneously, a low-resistance coaxial line 14 is established in a relatively large space above the medium-resistance coaxial line 5 (approximately 20-40 cm, with the direction away from the AC quantum resistance sample being upward and the direction closer to the AC quantum resistance sample being downward), ensuring a balance between low lead resistance and high thermal impedance. If only the medium-resistance coaxial line is used, the overall line impedance will be high. If only the low-resistance coaxial line is used, the low-temperature capability cannot be guaranteed. Detailed Implementation Method Seven

[0101] This embodiment is a further explanation of embodiments one, two, four to six. In this embodiment, a cover plate 13 is also included.

[0102] Cover plate 13 is fixed above sample fixing plate 1;

[0103] A space is provided between the cover plate 13 and the sample fixing plate 1 to accommodate the AC quantum resistor.

[0104] In this embodiment, the cover plate 13 and the sample fixing plate 1 cooperate to form a relatively closed environment, reducing the erosion of AC quantum resistor by external dust, water vapor, etc., and improving its working reliability. Detailed Implementation Method Eight

[0106] This embodiment is a further explanation of embodiment seven. In this embodiment, the sample fixing plate 1, the coaxial fixing plate 2, the base plate 7, the measuring rod 9, the flange 10, the reinforcing fixing column 12 and the cover plate 13 are all made of at least one of polyetherketone and polyamide ester.

[0107] In this embodiment, polyetherketone (PEEK) and polyamide ester are used as insulating materials, which can realize an ultra-low parasitic capacitance structure. The measured time constant of the overall structure is less than 10 ns. Detailed Implementation Method Nine

[0109] This embodiment is a further explanation of one of the embodiments two, four, five, six or eight. In this embodiment, the length of the medium resistance coaxial line 5 is 20 to 40 cm.

[0110] The present invention discloses a sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system, comprising a sample fixing plate and a coaxial fixing plate; both the sample fixing plate and the coaxial fixing plate are insulating plates; the sample fixing plate is fixed above the coaxial fixing plate; the coaxial fixing plate has at least seven perforations; the upper end face, lower end face, and inner sidewall of the perforations are covered with an integral conductive film layer; the upper end face and lower end face of the perforations are annular surfaces located on the upper and lower surfaces of the coaxial fixing plate, respectively; wherein the conductive film layers of the seven perforations are sequentially connected in series through a first wire located inside the coaxial fixing plate; the sample fixing plate is fixed with the same number of measuring needles as the perforations; the measuring needles all pass vertically through the upper and lower end faces of the sample fixing plate and are coaxially arranged corresponding to the perforations one by one.

[0111] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0112] Finally, it should be noted that the above description represents a preferred embodiment of the present invention. It should be pointed out that although preferred embodiments have been described, those skilled in the art, once they understand the basic inventive concept of the present invention, can make various improvements and modifications without departing from the principles described herein. These improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system, characterized in that, It includes a sample fixing plate (1) and a coaxial fixing plate (2); Both the sample fixing plate (1) and the coaxial fixing plate (2) are insulating plates; and the sample fixing plate (1) is fixed above the coaxial fixing plate (2); The coaxial fixing plate (2) is provided with at least seven through holes (3); The upper end face, lower end face and inner wall of the perforation (3) are covered with an integral conductive film layer; the upper end face and lower end face of the perforation (3) are annular surfaces located on the upper surface and lower surface of the coaxial fixing plate (2) respectively; In a clockwise or counterclockwise order, the seven perforations (3) correspond to the current excitation positive terminal, upstream voltage measurement positive terminal, upstream voltage measurement negative terminal, modulation terminal, current excitation negative terminal, downstream voltage measurement positive terminal, and downstream voltage measurement negative terminal of the AC quantum resistor, respectively; and the conductive film layers of the seven perforations (3) are connected in series in sequence through the first wire located inside the coaxial fixed plate (2). The sample fixing plate (1) is fixed with the same number of measuring needles (4) as the perforations (3); The measuring needles (4) all pass vertically through the upper and lower end faces of the sample fixing plate (1) and are coaxially arranged in correspondence with the perforations (3).

2. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 1, characterized in that, It also includes at least seven dual-segment coaxial cables; The dual-segment coaxial cable is composed of a medium-resistance coaxial line (5) of a set length and a low-resistance coaxial line (14) connected end to end; The resistance of the medium-resistance coaxial line (5) is 2Ω / m to 8Ω / m; the resistance of the low-resistance coaxial line (14) is 0.3Ω / m to 0.5Ω / m. Seven of the two-segment coaxial cables are inserted one-to-one into the seven through holes (3) at one end of the medium resistance coaxial cable (5); The outer conductor of the medium resistance coaxial line (5) extends out of or is flush with the upper end face of the corresponding perforation (3) and is electrically connected to the conductive film layer of the corresponding perforation (3). The inner conductor of the medium resistance coaxial line (5) is electrically connected to the pin of the corresponding measuring needle (4).

3. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 1 or 2, characterized in that, It also includes a grounding wire (6); The first conductor is grounded through the grounding wire (6).

4. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 3, characterized in that, The number of measuring needles (4) and the number of piercings (3) are both 12; All measuring needles (4) are divided into four groups; the four groups of measuring needles (4) are arranged in a centrally symmetrical manner with the central axis of the sample fixing plate (1) as the axis of symmetry; and some measuring needles (4) are packaged in TO-8. All perforations (3) are divided into four groups; the four groups of perforations (3) are arranged in a centrally symmetrical manner with the central axis of the coaxial fixing plate (2) as the axis of symmetry.

5. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 4, characterized in that, It also includes the chassis (7); A central support column (8) is vertically fixed to one end face of the chassis (7); The sample fixing plate (1) and the coaxial fixing plate (2) are coaxially fixed by the central support column (8).

6. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 5, characterized in that, It also includes a measuring rod (9) and a flange (10); The measuring rod (9) fixes the base plate (7) through the flange (10); The flange (10) is provided with four cable bundle holes (11); and the positions of the four cable bundle holes (11) correspond one-to-one with the positions of the four sets of through holes (3); The chassis (7) is provided with through holes corresponding to the four cable bundle holes (11); One end of each of the two coaxial cables is located in the measuring rod (9), and the other end passes out of the measuring rod (9) and passes through the corresponding cable bundle hole (11) and through hole in sequence.

7. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to any one of claims 1, 2, 4 to 6, characterized in that, It also includes a cover plate (13); The cover plate (13) is fixed above the sample fixing plate (1); A space is provided between the cover plate (13) and the sample fixing plate (1) to accommodate an AC quantum resistor.

8. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to claim 7, characterized in that, The materials of the sample fixing plate (1), coaxial fixing plate (2), chassis (7), measuring rod (9), flange (10), reinforcing fixing column (12) and cover plate (13) all include at least one of polyetherketone and polyamide ester.

9. The sample stage for reproducing AC quantum resistance in a liquid helium-free refrigeration system according to any one of claims 2, 4, 5, 6, and 8, characterized in that, The length of the medium resistance coaxial line (5) is 20-40cm.

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