Quantum voltage noise thermometer based on graphene oxychloride-chromium heterojunction quantum Hall resistance

Abstract

This invention discloses a quantum voltage noise thermometer based on a graphene / chromium oxychloride heterojunction quantum Hall resistor, comprising a heterojunction quantum Hall resistor, a quantum voltage pseudo-noise source, a switching circuit, two amplification and filtering circuits, and a data acquisition and processing circuit. The input terminals of the switching circuit are electrically connected to the output terminals of the heterojunction quantum Hall resistor and the quantum voltage pseudo-noise source, respectively, and the output terminals are sequentially connected to the amplification and filtering circuit and the data acquisition and processing circuit. The data acquisition and processing circuit includes two analog-to-digital converters and a data processing circuit. The input terminal of each analog-to-digital converter is electrically connected to the output terminal of one amplification and filtering circuit, and the output terminal is electrically connected to the data processing circuit. This invention uses a large-area graphene / chromium oxychloride heterojunction quantum Hall resistor as a resistance detector. Lateral conductance quantization can occur under a very small magnetic field, enabling primary temperature measurement over a wide range of strong magnetic fields and low temperatures.

Description

Technical Field

[0001] The invention relates to the technical field of temperature measurement, and in particular to a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor. Background Art

[0002] Temperature is one of the seven basic physical quantities in the International System of Units. Accurate temperature measurement has wide applications in energy, metallurgy, manufacturing, electronic technology, medical care, national defense, aerospace, and scientific research.

[0003] Thermodynamic temperature Kelvin has been defined by the Boltzmann constant, and the primary thermometer must be able to directly trace the temperature to the Boltzmann constant. At present, in the field of temperature measurement, there is still a lack of high-accuracy primary temperature measurement methods that can work in low temperature and strong magnetic field environments. The traditional low-temperature temperature scale based on the International System of Units, the latest is ITS-90 and PLTS-2000. At low temperatures, its main temperature sensors include rhodium iron resistors, silicon diodes, platinum resistors, thin film resistors, noise thermometers, etc. The readings of these low-temperature temperature sensors will have large deviations due to the influence of strong magnetic fields, and high-accuracy primary temperature measurements cannot be achieved. The quantum voltage noise thermometer uses a pulse-driven quantum voltage system to synthesize quantum pseudonoise, and uses this quantum pseudonoise to calibrate the thermal noise generated by the temperature measuring resistor at different temperatures, which can achieve high-accuracy primary temperature measurement. However, the resistance of the temperature measuring resistor used in the quantum voltage noise thermometer will change under low temperature and strong magnetic field. At the same time, in order to measure the resistance value, it is generally necessary to pass current through the resistor. The heating of the resistor will produce a temperature gradient, which affects its temperature measurement accuracy and cannot achieve accurate primary temperature measurement under low temperature and strong magnetic field. For many important application scenarios, such as particle accelerators, aerospace satellites, magnetic resonance imaging systems, cryogenic systems and scientific research, it is particularly important to achieve high-accuracy primary temperature measurement under low temperature and strong magnetic field environment.

[0004] Graphene-boron nitride heterojunction can achieve ultra-high mobility through Coulomb screening, thus becoming a new material system that can experimentally observe quantum Hall after GaAs semiconductor interface electron gas.

[0005] The inventors have found that a quasi-two-dimensional interface localized electronic state regulated by a vertical electric field is realized in a heterojunction of single-layer graphene and few-layer chromium-monooxygen-monochloride, which effectively regulates the energy band of graphene itself through Coulomb interaction and presents a novel quantum Hall state under a magnetic field. In this interface-coupled QHE phase, transverse conductance quantization can occur under a very small magnetic field, and this behavior can be maintained above liquid nitrogen temperature, with extremely strong robustness. For example, at a temperature of 77K, the magnetic field required for this system to achieve a transverse conductance quantization platform with a filling factor of ±2 can be as low as 350mT. The quantized conductance of traditional graphene requires a magnetic field of more than 10T to be obtained at 77K, which makes the quantized conductance boundary state take a key step from the liquid helium temperature zone to the liquid nitrogen temperature zone in future electronic applications such as topological superconductivity and quantum Hall-Fabry-Perot interference.

[0006] Based on this technical background, the present invention studies the quantum voltage noise thermometer of graphene chromium oxychloride heterojunction quantum Hall resistor. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention proposes a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor, which adopts a heterojunction quantum Hall resistor as a resistance detector and utilizes the fact that the heterojunction quantum Hall resistor remains unchanged in a wide range of strong magnetic fields and a wide range of low temperatures, thereby avoiding the problem of resistance value changes of other resistors in a low-temperature and strong magnetic field environment, and can realize primary temperature measurement in a low-temperature and strong magnetic field environment.

[0008] In order to achieve the above-mentioned object, the present invention provides a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor, comprising a heterojunction quantum Hall resistor, a quantum voltage pseudo-noise source, a two-way switch conversion circuit, an amplification and filtering circuit, and a data acquisition and processing circuit;

[0009] The input end of the switch conversion circuit is electrically connected to the output end of the heterojunction quantum Hall resistor and the quantum voltage pseudo-noise source respectively, and the output end is electrically connected to the two-way amplification and filtering circuit and the data acquisition and processing circuit in sequence;

[0010] Each amplification and filtering circuit includes a preamplifier, a first low-pass filter, a buffer amplifier, and a second low-pass filter which are electrically connected in sequence;

[0011] The data acquisition and processing circuit includes two analog-to-digital converters and a data processing circuit, the input end of each analog-to-digital converter is electrically connected to the output end of an amplifying and filtering circuit, and the output end is electrically connected to the data processing circuit;

[0012] The heterojunction quantum Hall resistor is formed by interface recombination of a single-layer graphene and a few-layer chromium-oxygen-chloride.

[0013] The technical effects of the present invention include:

[0014] (1) The quantum voltage noise thermometer based on heterojunction quantum Hall resistor proposed in the present invention adopts heterojunction quantum Hall resistor as a resistance detector. It utilizes the fact that heterojunction quantum Hall resistor remains unchanged in a wide range of strong magnetic fields and a wide range of low temperatures, thereby avoiding the problem of resistance value change of other resistors in a low temperature and strong magnetic field environment, and can realize primary temperature measurement in a low temperature and strong magnetic field environment.

[0015] (2) The quantum voltage noise thermometer based on heterojunction quantum Hall resistor proposed in the present invention adopts graphene / monooxygen monochromium chloride heterojunction as the quantum Hall platform generation medium, has a wide temperature measurement range, and can measure the precise temperature value of the noise source to be measured at the original level. At the same time, the temperature measurement circuit is simple, which reduces the cost of high-precision temperature measurement in low temperature and strong magnetic field environment.

[0016] (3) The present invention proposes a quantum voltage noise thermometer based on a heterojunction quantum Hall resistor. The heterojunction quantum Hall resistor is formed by the interface composite of a single-layer graphene and a few layers (with a thickness range of 5-100nm) of chromium monooxygen chloride. The quantization of the transverse conductivity can occur under a very small magnetic field, and this behavior can be maintained above the liquid nitrogen temperature, which has extremely strong robustness.

[0017] (4) The quantum voltage noise thermometer based on the heterojunction quantum Hall resistor proposed in the present invention has a data acquisition and processing circuit including two analog-to-digital converter data processing circuits connected to two-way amplification and filtering circuits. Through analog-to-digital conversion and data cross-correlation processing, the voltage noise of the room temperature readout circuit can be reduced, thereby making the voltage noise of the heterojunction quantum Hall resistor noise source dominant.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0020] Figure 1 This is a circuit topology diagram of the quantum voltage noise thermometer based on heterojunction quantum Hall resistor proposed in the present invention.

[0021] Description of reference numerals:

[0022] 1- low temperature and strong magnetic field environment, 2- heterojunction quantum Hall resistance, 3- low temperature environment, 4- quantum voltage pseudonoise source, 5- switch conversion circuit, 6- amplification and filtering circuit, 7- data acquisition and processing circuit, 8- preamplifier, 9- first low-pass filter, 10- buffer amplifier, 11- second low-pass filter, 12- analog-to-digital converter, 13- data processing circuit. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0024] In the present invention, unless otherwise specified, the directional words used, such as "upper and lower", generally refer to the upper and lower parts of the device in normal use, and "inside and outside" refer to the outline of the device. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0025] The present invention provides a quantum voltage noise thermometer of graphene chlorine oxychromium heterojunction quantum Hall resistor, such as Figure 1 As shown, it includes a heterojunction quantum Hall resistor 2, a quantum voltage pseudo-noise source 4, a switch conversion circuit 5, a two-way amplification and filtering circuit 6, and a data acquisition and processing circuit 7;

[0026] The input end of the switch conversion circuit 5 is electrically connected to the output end of the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4 respectively, and the output end is electrically connected to the two-way amplification and filtering circuit 6 and the data acquisition and processing circuit 7 in sequence;

[0027] Each amplifying and filtering circuit 6 comprises a preamplifier 8, a first low-pass filter 9, a buffer amplifier 10 and a second low-pass filter 11 which are electrically connected in sequence;

[0028] The data acquisition and processing circuit 7 includes two analog-to-digital converters 12 and a data processing circuit 13. The input end of each analog-to-digital converter 12 is electrically connected to the output end of an amplifier and filter circuit 6, and the output end is electrically connected to the data processing circuit 13.

[0029] The heterojunction quantum Hall resistor 2 is formed by the interface recombination of a single-layer graphene and a few-layer chromium-oxygen-chloride.

[0030] In the present invention, a heterojunction quantum Hall resistor 2 is used as a resistance detector. The heterojunction quantum Hall resistor 2 remains unchanged in a wide range of strong magnetic fields and a wide range of low temperatures, thereby avoiding the problem of resistance value changes of other resistors in a low-temperature and strong magnetic field environment 1, and realizing primary temperature measurement in a low-temperature and strong magnetic field environment 1.

[0031] According to the present invention, the area of ​​the single-layer graphene is greater than 40 microns × 40 microns;

[0032] The thickness of the few-layer chromium monooxygen chloride is 5-100nm;

[0033] The heterojunction quantum Hall resistor 2 is in a low temperature and strong magnetic field environment 1;

[0034] The temperature of low temperature and strong magnetic field environment 1 is 0-150K, and the magnetic field is 0.35-40T;

[0035] The quantum voltage pseudo-noise source 4 is in a low temperature environment 3;

[0036] The temperature of the low temperature environment 3 is 0-150K.

[0037] In the present invention, a graphene / chromium monooxygen chloride heterojunction is used as a quantum Hall platform generating medium, which has a wide temperature measurement range and can measure the precise temperature value of the noise source to be measured at the original level. At the same time, the temperature measurement circuit is simple, which reduces the cost of high-precision temperature measurement in low temperature and strong magnetic field environments.

[0038] In the present invention, the heterojunction quantum Hall resistor formed by the interface composite of a single-layer graphene and a few layers (with a thickness range of 5-100nm) of chromium monooxygen chloride can cause quantization of transverse conductivity under a very small magnetic field, and this behavior can be maintained above the liquid nitrogen temperature, with extremely strong robustness.

[0039] According to the present invention, the pseudo-noise source of quantum voltage pseudo-noise is synthesized using a Josephson junction array chip;

[0040] The number of Josephson junction array chips is 1-10 6 ;

[0041] The Josephson junction array chip generates Shapiro voltage steps and outputs quantum voltage pulses under microwave drive;

[0042] The frequency of microwaves is 1-100 GHz;

[0043] The Josephson junction is a high temperature superconducting Josephson junction based on yttrium barium copper oxide material, or a low temperature superconducting Josephson junction based on niobium, aluminum or niobium nitride material.

[0044] In the present invention, the quantum voltage pseudo-noise source 4 uses a Josephson junction array chip to synthesize quantum voltage pseudo-noise; the Josephson junction array generates a Shapiro voltage step under microwave drive, so that the Josephson junction array outputs a quantum voltage pulse, and the quantum voltage pseudo-noise signal is synthesized using arbitrary waveform synthesis technology; the Josephson junction in the Josephson array can be a high-temperature superconducting Josephson junction based on materials such as yttrium barium copper oxide, or a low-temperature superconducting Josephson junction based on materials such as niobium, aluminum or niobium nitride.

[0045] Preferably, the switch conversion circuit 5 is used to switch between the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4;

[0046] Each amplifying and filtering circuit 6 is used to read out, amplify and filter the noise signal of the heterojunction quantum Hall resistor 2 or the noise signal of the quantum voltage pseudo-noise source 4;

[0047] The data acquisition and processing circuit 7 is used to perform analog-to-digital conversion and data correlation processing on the received analog signal.

[0048] In the present invention, the data acquisition and processing circuit includes two analog-to-digital converter data processing circuits, and is connected to two-way amplification and filtering circuits. Through analog-to-digital conversion and data correlation processing, the voltage noise of the room temperature readout circuit can be reduced, so that the voltage noise of the heterojunction quantum Hall resistance noise source is dominant.

[0049] In the present invention, the amplification and filtering circuit 6 includes a preamplifier 8, a first low-pass filter 9, a buffer amplifier 10 and a second low-pass filter 11 electrically connected in sequence, which can reduce the voltage noise of the room temperature readout circuit, so that the voltage noise of the noise source of the heterojunction quantum Hall resistor 2 is dominant.

[0050] According to the present invention, the formula used by the thermometer to measure temperature is:

[0051]

[0052] Where T is the thermodynamic temperature, is the noise power of the heterojunction quantum Hall resistance to be measured, <V Q 2 > is the noise power of the quantum voltage pseudonoise source, ΔM is the bandwidth of the quantum voltage noise thermometer measurement system, n is the number of Shapiro steps, m is the number of Josephson junction array chips, k b is the Boltzmann constant, i is the Landau energy level, e is the elementary charge, and f is the frequency of the microwave.

[0053] In the present invention, is a constant, and the precise temperature value of the noise source to be measured can be measured at the original level.

[0054] According to the present invention, the formula used by the thermometer to measure temperature is derived from the noise power expression of the heterojunction quantum Hall resistor 2 and the noise power expression of the quantum voltage pseudo-noise source 4.

[0055] According to the present invention, the noise power expression of the heterojunction quantum Hall resistor 2 is:

[0056] <V T 2 >=4k b TRΔM;

[0057] Where R is the heterojunction quantum Hall resistance.

[0058] In the present invention, the temperature measurement principle of the noise temperature measurement method is based on the Nyquist equation: in represents the noise power, k b is the Boltzmann constant, T is the thermodynamic temperature, R is the detector resistance, and ΔM is the bandwidth of the quantum voltage noise thermometer measurement system. By measuring the thermal noise power and resistance of the resistor within a certain bandwidth, the thermodynamic temperature of the environment in which the resistor detector is located can be obtained.

[0059] Preferably, the calculation formula of the heterojunction quantum Hall resistance is:

[0060] R=R K / i;

[0061] Where i is the Landau energy level, R K is the Klitzing constant;

[0062] The expression of Klitzing constant is:

[0063] R K =h / e 2 ;

[0064] Here, h is Planck's constant.

[0065] In the present invention, a heterojunction quantum Hall resistor 2 is used as a detector resistor, and a method of switching measurement between the heterojunction quantum Hall resistor 2 and a reference voltage noise source is adopted to eliminate the influence of the measurement system bandwidth.

[0066] According to the present invention, the noise power expression of the quantum voltage pseudonoise source is:

[0067] <V Q 2 >=nmK J -1 f;

[0068] Among them, K J is the Josephson constant.

[0069] In the present invention, the quantum voltage noise thermometer based on the heterojunction quantum Hall resistor 2 uses a quantum voltage noise source as a reference voltage noise source to synthesize quantum voltage pseudonoise; the quantum voltage noise thermometer based on the heterojunction quantum Hall resistor 2 uses a cross-correlation technology to reduce the noise signal of the room temperature readout circuit.

[0070] According to the present invention, the expression of the Josephson constant is:

[0071] K J =2e / h.

[0072] The thermometer of the present invention has a wide temperature measurement range and can measure the precise temperature value of the noise source to be measured at the original level. At the same time, the temperature measurement circuit is simple, which reduces the cost of high-precision temperature measurement in low temperature and strong magnetic field environments.

[0073] The present invention will be described in more detail below through specific embodiments.

[0074] Example 1

[0075] like Figure 1 As shown, this embodiment provides a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor, including a heterojunction quantum Hall resistor 2, a quantum voltage pseudo-noise source 4, a switch conversion circuit 5, a two-way amplification and filtering circuit 6, and a data acquisition and processing circuit 7;

[0076] The input end of the switch conversion circuit 5 is electrically connected to the output end of the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4 respectively, and the output end is electrically connected to the two-way amplification and filtering circuit 6 and the data acquisition and processing circuit 7 in sequence;

[0077] Each amplifying and filtering circuit 6 comprises a preamplifier 8, a first low-pass filter 9, a buffer amplifier 10 and a second low-pass filter 11 which are electrically connected in sequence;

[0078] The data acquisition and processing circuit 7 includes two analog-to-digital converters 12 and a data processing circuit 13. The input end of each analog-to-digital converter 12 is electrically connected to the output end of an amplifier and filter circuit 6, and the output end is electrically connected to the data processing circuit 13.

[0079] The heterojunction quantum Hall resistor 2 in this embodiment uses a graphene / chromium-oxygen-chloride heterojunction as a quantum Hall platform generation medium, and is formed by a single-layer graphene with an area greater than 40 microns × 40 microns and a few layers (with a thickness range of 5-100 nm) of chromium-oxygen-chloride interface composite, and the operating temperature must be within the range of 0 to 100K; wherein, large-area graphene and chromium-oxygen-chloride can be obtained by mechanical cleavage, chemical vapor deposition and other methods;

[0080] The heterojunction quantum Hall resistor 2 is in a low temperature and strong magnetic field environment 1, where the temperature is about 4.2K and the magnetic field is about 0.35T; the heterojunction quantum Hall resistor 2 made of a single-layer graphene material is used as a temperature sensor; the switching conversion circuit 5 is used to switch between the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4;

[0081] The quantum voltage pseudo-noise source 4 is in a low temperature environment 3, and uses a Josephson junction array chip with about 300,000 based on niobium material to synthesize quantum voltage pseudo-noise, outputs quantum voltage pulses under 20 GHz microwave drive, and uses arbitrary waveform synthesis technology to synthesize quantum voltage pseudo-noise;

[0082] In this embodiment, the temperature of the low temperature environment is 10K;

[0083] In this embodiment, the quantum voltage pseudo-noise source 4 uses a Josephson junction array chip to synthesize quantum voltage pseudo-noise; the Josephson junction array generates a Shapiro voltage step under microwave drive, so that the Josephson junction array outputs a quantum voltage pulse, and the quantum voltage pseudo-noise signal is synthesized using arbitrary waveform synthesis technology;

[0084] In this embodiment, the formula used by the thermometer to measure temperature is:

[0085]

[0086] Where T is the thermodynamic temperature, is the noise power of the heterojunction quantum Hall resistance to be measured, <V Q 2 > is the noise power of the quantum voltage pseudonoise source, ΔM is the bandwidth of the quantum voltage noise thermometer measurement system, n is the number of Shapiro steps, m is the number of Josephson junction array chips, k b is the Boltzmann constant, i is the Landau energy level, e is the elementary charge, f is the frequency of microwaves, is a constant.

[0087] By using the parameters of this embodiment, the precise temperature value of the noise source to be measured can be measured at the original stage.

[0088] Example 2

[0089] like Figure 1 As shown, this embodiment provides a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor, including a heterojunction quantum Hall resistor 2, a quantum voltage pseudo-noise source 4, a switch conversion circuit 5, a two-way amplification and filtering circuit 6, and a data acquisition and processing circuit 7;

[0090] The input end of the switch conversion circuit 5 is electrically connected to the output end of the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4 respectively, and the output end is electrically connected to the two-way amplification and filtering circuit 6 and the data acquisition and processing circuit 7 in sequence;

[0091] Each amplifying and filtering circuit 6 comprises a preamplifier 8, a first low-pass filter 9, a buffer amplifier 10 and a second low-pass filter 11 which are electrically connected in sequence;

[0092] The data acquisition and processing circuit 7 includes two analog-to-digital converters 12 and a data processing circuit 13. The input end of each analog-to-digital converter 12 is electrically connected to the output end of an amplifier and filter circuit 6, and the output end is electrically connected to the data processing circuit 13.

[0093] The heterojunction quantum Hall resistor 2 in this embodiment uses a graphene / monochromium-oxygen-chloride heterojunction as a quantum Hall platform generation medium, and is formed by a single-layer graphene with an area greater than 40 microns × 40 microns and a few layers (with a thickness range of 70-100nm) of monochromium-oxygen-chloride interface composite, and the operating temperature must be within the range of 0 to 100K; wherein, large-area graphene and monochromium-oxygen-chloride can be obtained by mechanical cleavage, chemical vapor deposition and other methods;

[0094] The heterojunction quantum Hall resistor 2 is in a low temperature and strong magnetic field environment 1, where the temperature is about 12K and the magnetic field is about 1T; the heterojunction quantum Hall resistor 2 made of a single-layer graphene material is used as a temperature sensor; the switching conversion circuit 5 is used to switch between the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4;

[0095] The quantum voltage pseudo-noise source 4 is in a low temperature environment 3, and uses a Josephson junction array chip with about 400,000 niobium-based materials to synthesize quantum voltage pseudo-noise, outputs quantum voltage pulses under 15 GHz microwave drive, and uses arbitrary waveform synthesis technology to synthesize quantum voltage pseudo-noise;

[0096] In this embodiment, the temperature of the low temperature environment is 4.2K;

[0097] In this embodiment, the quantum voltage pseudo-noise source 4 uses a Josephson junction array chip to synthesize quantum voltage pseudo-noise; the Josephson junction array generates a Shapiro voltage step under microwave drive, so that the Josephson junction array outputs a quantum voltage pulse, and the quantum voltage pseudo-noise signal is synthesized using arbitrary waveform synthesis technology;

[0098] In this embodiment, the formula used by the thermometer to measure temperature is:

[0099]

[0100] Where T is the thermodynamic temperature, is the noise power of the heterojunction quantum Hall resistance to be measured, <VQ 2 > is the noise power of the quantum voltage pseudonoise source, ΔM is the bandwidth of the quantum voltage noise thermometer measurement system, n is the number of Shapiro steps, m is the number of Josephson junction array chips, k b is the Boltzmann constant, i is the Landau energy level, e is the elementary charge, f is the frequency of microwaves, is a constant.

[0101] By using the parameters of this embodiment, the precise temperature value of the noise source to be measured can be measured at the original stage.

[0102] Example 3

[0103] like Figure 1 As shown, this embodiment provides a quantum voltage noise thermometer of a graphene chlorine oxychromium heterojunction quantum Hall resistor, including a heterojunction quantum Hall resistor 2, a quantum voltage pseudo-noise source 4, a switch conversion circuit 5, a two-way amplification and filtering circuit 6, and a data acquisition and processing circuit 7;

[0104] The input end of the switch conversion circuit 5 is electrically connected to the output end of the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4 respectively, and the output end is electrically connected to the two-way amplification and filtering circuit 6 and the data acquisition and processing circuit 7 in sequence;

[0105] Each amplifying and filtering circuit 6 comprises a preamplifier 8, a first low-pass filter 9, a buffer amplifier 10 and a second low-pass filter 11 which are electrically connected in sequence;

[0106] The data acquisition and processing circuit 7 includes two analog-to-digital converters 12 and a data processing circuit 13. The input end of each analog-to-digital converter 12 is electrically connected to the output end of an amplifier and filter circuit 6, and the output end is electrically connected to the data processing circuit 13.

[0107] The heterojunction quantum Hall resistor 2 in this embodiment uses a graphene / monochromium-oxygen-chloride heterojunction as a quantum Hall platform generation medium, and is formed by a single-layer graphene with an area greater than 40 microns × 40 microns and a few layers (with a thickness range of 30-100nm) of monochromium-oxygen-chloride interface composite, and the operating temperature must be within the range of 0 to 150K; wherein, large-area graphene and monochromium-oxygen-chloride can be obtained by mechanical cleavage, chemical vapor deposition and other methods;

[0108] The heterojunction quantum Hall resistor 2 is in a low temperature and strong magnetic field environment 1, where the temperature is about 22K and the magnetic field is about 2T; the heterojunction quantum Hall resistor 2 made of a single-layer graphene material is used as a temperature sensor; the switching conversion circuit 5 is used to switch between the heterojunction quantum Hall resistor 2 and the quantum voltage pseudo-noise source 4;

[0109] The quantum voltage pseudo-noise source 4 is in a low temperature environment 3, and uses a Josephson junction array chip with about 500,000 based on niobium materials to synthesize quantum voltage pseudo-noise, outputs quantum voltage pulses under 30 GHz microwave drive, and uses arbitrary waveform synthesis technology to synthesize quantum voltage pseudo-noise;

[0110] In this embodiment, the temperature of the low temperature environment is 20K;

[0111] In this embodiment, the quantum voltage pseudo-noise source 4 uses a Josephson junction array chip to synthesize quantum voltage pseudo-noise; the Josephson junction array generates a Shapiro voltage step under microwave drive, so that the Josephson junction array outputs a quantum voltage pulse, and the quantum voltage pseudo-noise signal is synthesized using arbitrary waveform synthesis technology;

[0112] In this embodiment, the formula used by the thermometer to measure temperature is:

[0113]

[0114] Where T is the thermodynamic temperature, is the noise power of the heterojunction quantum Hall resistance to be measured, <V Q 2 > is the noise power of the quantum voltage pseudonoise source, ΔM is the bandwidth of the quantum voltage noise thermometer measurement system, n is the number of Shapiro steps, m is the number of Josephson junction array chips, k b is the Boltzmann constant, i is the Landau energy level, e is the elementary charge, f is the frequency of microwaves, is a constant.

[0115] By using the parameters of this embodiment, the precise temperature value of the noise source to be measured can be measured at the original stage.

[0116] The quantum voltage noise thermometer based on heterojunction quantum Hall resistor in this embodiment adopts heterojunction quantum Hall resistor as a resistance detector, and utilizes the fact that heterojunction quantum Hall resistor remains unchanged in a wide range of strong magnetic fields and a wide range of low temperatures, thereby avoiding the problem of resistance value changes of other resistors in a low temperature and strong magnetic field environment, and can realize primary temperature measurement in a low temperature and strong magnetic field environment.

[0117] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A quantum voltage noise thermometer of graphene chlorine oxychromium heterojunction quantum Hall resistor, characterized in that: It includes heterojunction quantum Hall resistor, quantum voltage pseudo-noise source, switch conversion circuit, two-way amplification and filtering circuit, and data acquisition and processing circuit; The input end of the switch conversion circuit is electrically connected to the output end of the heterojunction quantum Hall resistor and the quantum voltage pseudo-noise source respectively, and the output end is electrically connected to the two-way amplification and filtering circuit and the data acquisition and processing circuit in sequence; Each amplification and filtering circuit includes a preamplifier, a first low-pass filter, a buffer amplifier, and a second low-pass filter which are electrically connected in sequence; The data acquisition and processing circuit includes two analog-to-digital converters and a data processing circuit, the input end of each analog-to-digital converter is electrically connected to the output end of an amplifying and filtering circuit, and the output end is electrically connected to the data processing circuit; The heterojunction quantum Hall resistor is formed by a single-layer graphene and a few-layer chromium-oxygen-chloride through interface recombination; The area of ​​the single-layer graphene is greater than 40 microns×40 microns; The thickness of the few-layer chromium monooxygen monochloride is 5-100 nm; The heterojunction quantum Hall resistor is in a low temperature and strong magnetic field environment; The temperature of the low temperature and strong magnetic field environment is 0-150K, and the magnetic field is 0.35-40T; The quantum voltage pseudo-noise source is in a low temperature environment; The temperature of the low temperature environment is 0-150K; The pseudo-noise source of the quantum voltage pseudo-noise is synthesized using a Josephson junction array chip; The number of the Josephson junction array chips is 1-10 6 ; The Josephson junction array chip generates a Shapiro voltage step output quantum voltage pulse under microwave drive; The frequency of the microwave is 1-100 GHz; The Josephson junction is a high-temperature superconducting Josephson junction based on yttrium-barium-copper-oxide material, or a low-temperature superconducting Josephson junction based on niobium, aluminum or niobium nitride material; The formula used for measuring temperature by the quantum voltage noise thermometer is: ； Where T is the thermodynamic temperature, < V T 2 > is the noise power of the heterojunction quantum Hall resistance to be measured, < V Q 2 > is the noise power of the quantum voltage pseudonoise source, is the bandwidth of the quantum voltage noise thermometer measurement system, n is the number of Shapiro steps, m is the number of Josephson junction array chips, k b is the Boltzmann constant, i is the Landau energy level, e is the elementary charge, f is the frequency of microwaves.

2. The quantum voltage noise thermometer according to claim 1, characterized in that: The switch conversion circuit is used to switch between the heterojunction quantum Hall resistance and the quantum voltage pseudo-noise source; Each amplifying and filtering circuit is used to read out, amplify and filter the noise signal of the heterojunction quantum Hall resistor or the noise signal of the quantum voltage pseudo-noise source; The data acquisition and processing circuit is used for performing analog-to-digital conversion and data correlation processing on the received analog signal.

3. The quantum voltage noise thermometer according to claim 1, characterized in that: The formula used for measuring temperature by the quantum voltage noise thermometer is derived from the noise power expression of the heterojunction quantum Hall resistor and the noise power expression of the quantum voltage pseudo-noise source.

4. The quantum voltage noise thermometer according to claim 3, characterized in that: The noise power expression of the heterojunction quantum Hall resistance is: ； in, R is the heterojunction quantum Hall resistance.

5. The quantum voltage noise thermometer according to claim 4, characterized in that: The calculation formula of the heterojunction quantum Hall resistance is: R = R K / i ； in, i is the Landau energy level, R K is the Klitzing constant; The expression of the Klitzing constant is: R K = h / e 2 ； Here, h is Planck's constant.

6. The quantum voltage noise thermometer according to claim 5, characterized in that: The noise power expression of the quantum voltage pseudonoise source is: < V Q 2 >= K J -1 f ； in, K J is the Josephson constant.

7. The quantum voltage noise thermometer according to claim 6, characterized in that: The expression of the Josephson constant is: K J =2 e / h .

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