A scanning tunneling microscope device for electron spin resonance detection

Abstract

The application discloses a scanning tunnel microscope device for realizing electron spin resonance detection and relates to the technical field of microscopes. The scanning tunnel microscope device for realizing electron spin resonance detection comprises a base, a needle tip arranged on the base, the needle tip being configured to run and generate a tunneling current with a sample on the base, a microwave excitation component, the microwave excitation component comprising an antenna and a microwave signal generation and modulation structure, the antenna being arranged on the base, and the microwave signal generation and modulation structure being configured to transmit microwave signals to the antenna and / or the needle tip, and a magnet component arranged on the side of the base away from the needle tip. The microwave radiation direction of the antenna is towards the needle tip. The technical scheme of the application is characterized in that the antenna is arranged on one side of the base, and the microwave signal generation and modulation structure is configured to inject microwave signals to the antenna and / or the needle tip, so as to improve the microwave excitation efficiency and frequency coverage capability and significantly improve the stability of the spin resonance signal and the system adaptability.

Description

Technical Field

[0001] This invention relates to the field of microscopy, and in particular to a scanning tunneling microscope device for realizing electron spin resonance detection. Background Technology

[0002] The current ESR-STM (Electron Spin Resonance - Scanning Tunneling Microscopy) technology has integrated electron spin resonance with scanning tunneling microscopy, enabling single-spin detection and fully electronically controlled operation of atomic or molecular spins.

[0003] Existing ESR-STM systems typically employ a single-path microwave injection method, which measures the spin state of sample atoms under the influence of microwaves and magnetic fields. However, this method is prone to problems such as reflection loss, standing wave interference, and uneven field distribution due to the mismatch between the probe and the sample structure during microwave signal propagation. This makes it difficult to achieve high-fidelity excitation and control of local spin systems. Summary of the Invention

[0004] The main objective of this invention is to propose a scanning tunneling microscope device for realizing electron spin resonance detection, aiming to solve the technical problem that single-path microwave injection methods easily lead to microwave signal reflection loss.

[0005] To achieve the above objectives, the present invention proposes a scanning tunneling microscope device for electron spin resonance detection, comprising:

[0006] A base on which a needle tip is provided, the needle tip being configured such that a tunneling current is generated between the needle tip and a sample on the base through a quantum tunneling effect; A microwave excitation assembly, comprising a microwave signal generating and modulation structure and an antenna, wherein the antenna is disposed on one side of the base, and the microwave excitation assembly transmits microwave signals to the antenna and / or the tip; A superconducting electromagnet assembly, wherein the superconducting electromagnet assembly is configured such that the magnetic field of the superconducting electromagnet assembly is concentrated and distributed between the needle tip and the sample; The microwave radiation from the antenna is directed toward the needle tip and the sample.

[0007] In one embodiment, the microwave generating and modulation structure includes a microwave signal source, which is connected to the needle tip via a first path and to the antenna via a second path.

[0008] In one embodiment, a first impedance matching section and a third impedance matching section are connected on the first path, and a second impedance matching section and a fourth impedance matching section are connected on the second path.

[0009] In one embodiment, the scanning tunneling microscope device for realizing electron spin resonance detection further includes a main unit, the tip is facing the sample on the base, the main unit is connected to the tip, and the sample is connected to the main unit to form a circuit, the tunneling current is excited by the quantum tunneling effect between the tip and the sample, and is fed back to the main unit through the circuit; Wherein, a DC microwave coupler is connected to the first path, the main unit is connected to the DC microwave coupler, and the DC microwave coupler is configured such that the DC microwave coupler transmits the tunneling current, or the tunneling current and microwave, on the first path through coupling.

[0010] In one embodiment, the microwave generation and modulation structure further includes a waveform generator connected to the DC microwave coupler and the microwave signal source.

[0011] In one embodiment, the scanning tunneling microscope device for realizing electron spin resonance detection further includes a scanning component driven by the piezoelectric effect, the tip being connected to the scanning component, and the scanning component being configured such that the scanning component drives the tip to move, thereby controlling the relative position between the tip and the sample.

[0012] In one embodiment, the scanning tunneling microscope device for realizing electron spin resonance detection further includes a temperature control component that covers the base, the antenna, and the tip. The temperature control component is configured to control the temperature to gradually change towards the base so that the measurement environment is in a low-temperature state.

[0013] In one embodiment, the temperature control component includes multiple metal shielding layers and multiple cold plates. The multiple metal shielding layers are nested and connected in sequence, and a temperature shielding space is formed between two adjacent metal shielding layers. At least one cold plate is provided in one of the temperature shielding spaces.

[0014] In one embodiment, the plurality of cold plates are fixed to each other by infusion pipes, and the infusion pipes pass through the plurality of metal shielding layers, and the infusion pipes transmit heat-conducting medium; The scanning component is connected to the base, and the base is wrapped with multiple metal shielding layers. The base is connected to the cold plate via a spring, or the scanning component is connected to the cold plate via a spring.

[0015] In one embodiment, a temperature sensor is provided on one side of the cold plate and a temperature sensor is provided on one side of the superconducting electromagnet assembly. The plurality of temperature sensors are configured to provide feedback on temperature changes to adjust the heat transfer efficiency of the heat transfer medium.

[0016] The technical solution of this invention provides an antenna on one side of the base. A microwave signal generation and modulation structure injects microwave signals into the antenna and / or the tip. The microwave signal is output by the antenna or the tip alone, or by the antenna and the tip together. This improves the microwave excitation efficiency and frequency coverage. It is suitable for low-frequency high-efficiency excitation and can also support high-frequency broadband measurement, significantly improving the stability of the spin resonance signal and the system adaptability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a scanning tunneling microscope device for electron spin resonance detection provided by the present invention; Figure 2 A schematic diagram of the first impedance matching section and the third impedance matching section in an embodiment of the scanning tunneling microscope device for realizing electron spin resonance detection provided by the present invention; Figure 3 A schematic diagram of the antenna structure in one embodiment of the scanning tunneling microscope device for electron spin resonance detection provided by the present invention; Figure 4 A schematic diagram of the base structure in one embodiment of the scanning tunneling microscope device for electron spin resonance detection provided by the present invention; Figure 5 This is a schematic diagram of the temperature control component in one embodiment of the scanning tunneling microscope device for realizing electron spin resonance detection provided by the present invention.

[0019] Explanation of icon numbers: 10. Main unit; 11. DC microwave coupler; 20. Microwave excitation assembly; 21. Waveform generator; 22. Microwave signal source; 24. Impedance matching network; 241. Second impedance matching section; 242. First impedance matching section; 243. Third impedance matching section; 244. Fourth impedance matching section; 245. First connecting line; 246. First coaxial connector; 247. Flexible coaxial line; 35. Temperature sensor; 40. Antenna; 41. Substrate; 42. Second coaxial connector; 43. Antenna unit; 44. Second connecting line; 50. Temperature control assembly; 51. Cold plate; 511. First cold plate; 512. Second cold plate; 513. Third cold plate; 60. Needle tip; 70. Base; 71. Magnet assembly; 80. Needle tip clamp; 90. Scanning assembly; 91. Piezoelectric ceramic tube; 92. Piezoelectric ceramic stack.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] The current ESR-STM (Electron Spin Resonance - Scanning Tunneling Microscopy) technology has integrated electron spin resonance with scanning tunneling microscopy, enabling single-spin detection and fully electronically controlled operation of atomic or molecular spins.

[0025] Existing ESR-STM systems typically employ a single-path microwave injection method, which measures the spin state of sample atoms under the influence of microwaves and magnetic fields. However, this method is prone to problems such as reflection loss, standing wave interference, and uneven field distribution due to the mismatch between the probe and the sample structure during microwave signal propagation. This makes it difficult to achieve high-fidelity excitation and control of local spin systems.

[0026] This invention proposes a scanning tunneling microscope device for realizing electron spin resonance detection.

[0027] Please see Figure 1 In one embodiment of the present invention, the scanning tunneling microscope device for realizing electron spin resonance detection includes: A base 70 is provided with a needle tip 60, which is configured such that the needle tip 60 and the sample on the base 70 generate a tunneling current through the quantum tunneling effect. The microwave excitation assembly 20 includes a microwave signal generation and modulation structure and an antenna 40. The antenna 40 is disposed on one side of the base 70. The microwave excitation assembly 20 transmits microwave signals to the antenna 40 and / or the tip 60. Superconducting electromagnet assembly 71 is configured such that the magnetic field of the superconducting electromagnet assembly is concentrated between the needle tip 60 and the sample. The microwave radiation from the antenna 40 is directed toward the needle tip 60 and the sample.

[0028] like Figure 1 As shown, the base 70 is a support platform for supporting the sample, and a sample holder is provided on the support platform.

[0029] It is understandable that when the sample is placed on the base 70, the tip 60 is facing the sample so that a tunneling current can be generated between the tip 60 and the sample when the tip 60 is running. By observing and analyzing the current, the spin state of the sample atoms can be observed, analyzed and measured.

[0030] It should be noted that due to the limitations of needle tip thickness and movement, the microwaves injected through the needle tip in coaxial wiring are usually low-frequency. When low-frequency microwaves are output through the needle tip, their reflection loss is low. However, when the needle tip outputs high-frequency microwaves, its reflection loss increases, making it difficult to achieve high-fidelity excitation and control of atomic spin states.

[0031] Therefore, an antenna 40 is installed on one side of the base 70.

[0032] It is understandable that the antenna 40 is used to output high-frequency microwaves, and the antenna 40 is oriented directly towards the sample so that the high-frequency microwaves output by the antenna 40 can stably and with high fidelity excite the spin state of the sample atoms.

[0033] In another embodiment, both the antenna 40 and the needle tip output microwaves. The microwaves output by the two are modulated to output microwaves of the required frequency. Together with the superconducting electromagnet component 71, a local high-intensity alternating magnetic field is formed, which enhances the coupling efficiency between the microwave and the spin system, expands the frequency response range, and forms an alternating magnetic field in the sample local area to drive the electron spin to flip at the resonant frequency. This enables the excitation and manipulation of the spin state, improves the excitation and detection sensitivity of the electron spin resonance signal, and is used to detect its resonance response.

[0034] In one embodiment, the superconducting electromagnet assembly 71 includes an electromagnet, which is composed of a cryogenic superconducting coil wound around a permanent magnet.

[0035] Understandably, when the low-temperature superconducting coil is energized, the electromagnet provides a constant magnetic field to the base 70. Combined with the microwaves output by the antenna 40 and / or the tip 60, this causes changes in the spin state of the sample atoms, affecting the magnitude of the tunneling current and producing different physical phenomena.

[0036] In order to concentrate the magnetic field of the superconducting electromagnet assembly 71 on the needle tip 60 and the sample, the superconducting electromagnet assembly 71 is placed on the base 70 and located below the sample holder.

[0037] It is understandable that when the sample is placed on the sample holder, the area with the strongest magnetic field generated by the operation of the superconducting electromagnet assembly 71 is distributed between the needle tip 60 and the sample.

[0038] Furthermore, the microwave signal generation and modulation structure injects microwave signals into the antenna 40 and / or the tip 60. In order to achieve a single-path microwave signal output from the antenna 40 or the tip 60, a switching structure needs to be set up.

[0039] It is understandable that by operating the switching structure, the microwave signal generation and modulation structure can be switched between the antenna 40 and the tip 60, so as to achieve microwave signal output from different paths.

[0040] The technical solution of the present invention provides an antenna 40 on one side of the base 70. The microwave signal generation and modulation structure injects microwave signals into the antenna 40 and / or the tip 60. The microwave signal is output by the antenna 40 or the tip 60 alone, or by the antenna 40 and the tip 60 jointly. This improves the microwave excitation efficiency and frequency coverage capability, making it suitable for low-frequency high-efficiency excitation as well as high-frequency broadband measurement, and significantly improving the stability of the spin resonance signal and the system adaptability.

[0041] In one embodiment, the microwave generation and modulation structure includes a microwave signal source 22, which is connected to the needle tip 60 via a first path and to the antenna 40 via a second path.

[0042] Understandably, microwave signal source 22 is used to generate and transmit microwave signals to needle tip 60 and / or antenna 40.

[0043] Furthermore, both the first path and the second path are transmission paths for microwave signals, meaning that both the first path and the second path can be lines that facilitate microwave signal transmission.

[0044] In another embodiment, the first path and the second path are respectively connected to a switching structure, thereby enabling the transmission of microwave signals in the first path and / or the second path by controlling the switching structure.

[0045] In one embodiment, a first impedance matching part 242 and a third impedance matching part 243 are connected on the first path, and a second impedance matching part 241 and a fourth impedance matching part 244 are connected on the second path.

[0046] It should be noted that when microwave signals are transmitted in the first or second path, the electromagnetic wave energy is not fully transferred to the load due to impedance discontinuity, but is partially reflected back to the source, resulting in reflection loss.

[0047] In one embodiment, the impedance matching network 24 includes a first impedance matching section 242, a second impedance matching section 241, a third impedance matching section 243, and a fourth impedance matching section 244.

[0048] like Figure 2 As shown, the first impedance matching part 242 and the third impedance matching part 243 are connected in series, and the second impedance matching part 241 and the fourth impedance matching part 244 are connected in series.

[0049] It should be noted that the first impedance matching part 242 and the second impedance matching part 241 are active impedance matching networks, while the third impedance matching part 243 and the fourth impedance matching part 244 are passive impedance matching networks.

[0050] It is understandable that by relying on impedance matching networks to adjust the impedance relationship of different parts in the transmission line, efficient transmission of microwave signals can be achieved, reducing reflection loss or distortion.

[0051] like Figure 4 As shown, the first impedance matching part 242 is connected to the first connecting line 245. One end of the first connecting line 245 is connected to the first coaxial connector 246. The first coaxial connector 246 is connected to the third impedance matching part 243. One end of the flexible coaxial line 247 is connected to the third impedance matching part 243, and the other end is connected to the pin tip.

[0052] like Figure 3 As shown, the antenna 40 includes a substrate 41, a second impedance matching part 241 connected to a second connecting line 44, one end of the second connecting line 44 connected to a second coaxial connector 42, the second coaxial connector 42 connected to the substrate 41 through a connecting terminal, an antenna part 43 disposed on the surface of the substrate 41, and a fourth impedance matching part 244 connected between the antenna part 43 and the connecting terminal.

[0053] In one embodiment, the scanning tunneling microscope device for realizing electron spin resonance detection further includes a main unit 10, with the tip 60 facing the sample on the base 70. The main unit 10 is connected to the tip, and the sample is connected to the main unit 10 to form a circuit. The tunneling current is excited by the quantum tunneling effect between the tip and the sample and is fed back to the main unit 10 through the circuit. In this configuration, a DC-microwave coupler 11 is connected to the first path, and the main unit 10 is connected to the DC-microwave coupler 11. The DC-microwave coupler 11 is configured to transmit tunneling current, or tunneling current and microwave, in the first path through coupling.

[0054] like Figure 1 As shown, the main unit 10 is a central processing unit, which is connected to the pin tip 60 and the base 70.

[0055] Understandably, a DC bias voltage is applied between the needle tip and the sample via a central processing unit, and the tunneling current is measured using the quantum tunneling effect.

[0056] It should be noted that the distance between the needle tip and the sample is in the nanometer range, and the resulting tunneling current is only in the range of picoamperes (pA) to nanoamperes (nA), which cannot be directly detected by conventional circuits.

[0057] For this purpose, a current amplifier or transimpedance amplifier is connected between the base 70 and the main unit 10 to amplify and convert the tunneling current (typically in the pA to nA range) between the tip and the sample for subsequent signal processing and image generation.

[0058] Furthermore, after the tunneling current is transmitted to the host unit 10, the host unit 10 receives the tunneling signal and performs signal and image processing, thereby realizing atomic-level resolution surface morphology imaging and local electronic state detection.

[0059] Furthermore, the main unit 10 includes a DC power supply that provides a DC bias voltage to the tip. By providing a constant DC voltage to the tip, the tunneling current generated when the tip outputs to the sample is transmitted to the central processing unit for analysis, thus avoiding distortion and ensuring the accuracy of the measurement results.

[0060] The main unit 10 also includes drive signals.

[0061] Understandably, the main unit 10 outputs drive signals to facilitate the control of the equipment's operation.

[0062] like Figure 1 As shown, the needle tip is directly opposite the base 70, and there is a gap between the needle tip and the sample on the base 70.

[0063] It should be noted that the smaller the gap between the needle tip and the sample, the larger the tunneling current generated, which facilitates the accuracy of signal and image processing in the central processing unit.

[0064] It is understandable that microwaves are output through the tip 60 or the antenna 40, and under the action of the superconducting electromagnet component 71, the atoms are excited by microwaves and tunneling current is generated. Since the microwaves and magnetic fields can easily affect the magnitude of the tunneling current when the gap distance remains unchanged, the microwave signal and the magnitude of the magnetic field can be adjusted as needed to facilitate the clear expression and display of the physical phenomena of the atoms by the tunneling current.

[0065] Furthermore, when both the DC bias voltage output from the main unit 10 and the microwave signal output from the microwave signal source 22 need to be output through the needle tip, the DC bias voltage and the microwave signal are coupled through the coupler 11, and the coupled signal is input to the needle tip. In this way, when measuring the sample, a tunneling current is generated, which facilitates the analysis of the sample.

[0066] It is understandable that the coupler couples the DC bias voltage and the microwave signal to transmit the coupled signal to the first impedance matching part 242 and the third impedance matching part 243, and then to the needle tip. The first impedance matching part 242 and the third impedance matching part 243 reduce reflection loss and thus improve transmission accuracy.

[0067] In one embodiment, the microwave generation and modulation structure further includes a waveform generator 21, which is connected to a DC microwave coupler 11 and a microwave signal source 22.

[0068] Understandably, waveform generator 21 is used to chop and modulate DC bias voltage and microwave signal.

[0069] It should be noted that tunneling current is a major source of decoherence, and strong coupling between spin and substrate can introduce interference from crystal field splitting and spin-orbit coupling, affecting the accuracy of the results.

[0070] It is understandable that the DC bias voltage and the microwave signal are periodically pulsed by the waveform generator 21, so that when the microwave is excited, the microwave is output intermittently. During the microwave output period, the spin of the atoms changes and coherent with other atoms around them. When the microwave output stops, decoherence occurs between the atoms.

[0071] By using periodic pulse modulation, the electron spin resonance excitation and precise detection of individual atoms or molecules can be achieved, significantly improving the signal-to-noise ratio and spatial resolution.

[0072] In one embodiment, the scanning tunneling microscope device for realizing electron spin resonance detection further includes a scanning component 90 driven by the piezoelectric effect, with a tip 60 connected to the scanning component 90. The scanning component 90 is configured such that the scanning component 90 drives the tip 60 to move, thereby controlling the relative position between the tip 60 and the sample.

[0073] It should be noted that after the sample is placed on the base 70, the position of the needle tip needs to be adjusted in order to perform multi-position detection on the sample surface.

[0074] In this way, the needle tip is connected to the scanning component 90, and the position of the needle tip relative to the sample is adjusted by the power output of the scanning component 90.

[0075] In another embodiment, the scanning component 90 includes a piezoelectric ceramic stack 92 and a piezoelectric ceramic tube 91. The piezoelectric ceramic stack 92 is connected to the piezoelectric ceramic tube 91, and both the piezoelectric ceramic stack 92 and the piezoelectric ceramic tube 91 are connected to the main body 10. The needle tip is connected to the piezoelectric ceramic tube.

[0076] It is understandable that when the main body 10 outputs a drive signal, the piezoelectric ceramic stack 92 achieves coarse motion control of the piezoelectric ceramic tube 91 through the piezoelectric effect, thereby realizing the horizontal movement, vertical stepping and withdrawal functions of the piezoelectric ceramic tube and the needle tip; the piezoelectric ceramic tube 91 performs fine motion control through the piezoelectric effect, thereby realizing fine position control of the needle tip.

[0077] It should be noted that the piezoelectric ceramic tube 91 achieves nanometer-level displacement control of the needle tip, while the piezoelectric ceramic stack 92 achieves micrometer-level displacement control of the needle tip.

[0078] It should be noted that the maximum distance of the piezoelectric ceramic tube 91 controlled by displacement is less than or equal to the distance of one displacement controlled by the piezoelectric ceramic stack 92.

[0079] Furthermore, in order to fix the needle tip to the piezoelectric ceramic tube 91, a needle tip clamp 80 is connected to the piezoelectric ceramic tube 91. The needle tip clamp 80 is connected to the needle tip, and the needle tip 60 is connected to a flexible coaxial line 247, which is connected to the main body 10.

[0080] Understandably, the needle tip clamp 80 not only clamps the needle tip 60, but also facilitates a good connection between the needle tip and the flexible coaxial line 247.

[0081] In one embodiment, the scanning tunneling microscope apparatus for realizing electron spin resonance detection further includes a temperature control component 50, which covers the base 70, the antenna 40 and the tip 60. The temperature control component 50 is configured to control the temperature to gradually change towards the base 70 so that the measurement environment is in a low-temperature state.

[0082] It should be noted that the measurement accuracy and stability of scanning tunneling microscopes are highly dependent on the ambient temperature. The lower the temperature, the less thermal drift and noise the system has, and the lower the detection and measurement deviation.

[0083] To this end, a temperature control component 50 is set up to keep the space between the sample and the needle tip at a low temperature and maintain the low temperature, thereby reducing the non-uniform deformation of various parts caused by temperature difference, avoiding uncontrollable offset of the relative position of the needle tip and the sample, and thus reducing detection deviation.

[0084] Furthermore, the operation of the temperature control component creates a gradient temperature region within the scanning tunneling microscope device that enables electron spin resonance detection, and the temperature at the location of the tip and the base 70 is in a low-temperature region, placing the tip and the sample in the same low-temperature region to avoid deviation that could affect the accuracy of the detection.

[0085] Moreover, the gradient temperature zone setting ensures a constant temperature between different zones, preventing temperature changes from affecting the detection.

[0086] In one embodiment, the temperature control component 50 includes a plurality of metal shielding layers 52 and a plurality of cold plates 51. The plurality of metal shielding layers 52 are nested and connected in sequence, and a temperature shielding space is formed between two adjacent metal shielding layers 52. At least one cold plate 51 is provided in one temperature shielding space.

[0087] It should be noted that the metal shielding layer can shield both external electromagnetic radiation and thermal radiation, and also has a heat conduction function.

[0088] To achieve isolation between different temperature zones, multiple metal shielding layers 52 are set up, and the multiple metal shielding layers 52 are nested and connected in sequence, with the temperature gradually decreasing from the outside to the inside. In this way, the low temperature of the area where the needle tip and the sample are located is kept constant through the gradual wrapping temperature zone distribution, thereby ensuring the stability of the detection imaging.

[0089] The cold plate 51 is located on the top surface of the metal shielding layer 52.

[0090] In one embodiment, the sample and the needle tip are located on one side of a cold plate 51 and within the central metal shielding layer 52.

[0091] In another embodiment, such as Figure 5 As shown, the temperature control component includes a first cold plate 511, a second cold plate 512, and a third cold plate 513. The first cold plate 511, the second cold plate 512, and the third cold plate 513 are arranged in a vertical row. The first cold plate 511, the second cold plate 512, and the third cold plate 513 are all located on the top surface of the metal shielding layer 52. A heat-conducting medium flows inside the first cold plate 511, the second cold plate 512, and the third cold plate 513 to achieve temperature control within the temperature shielding space. The gradient temperature control stabilizes the constant temperature within the temperature shielding space where the needle tip and the sample are located.

[0092] It should be noted that different cold plate areas have different temperatures. In order to minimize heat conduction, different coaxial cables need to be selected. The temperature of the first cold plate 511 is the first temperature, the temperature of the second cold plate 512 is the second temperature, and the temperature of the third cold plate 513 is the third temperature. The first temperature, the second temperature and the third temperature decrease in descending order.

[0093] Understandably, since the coaxial cable passes through multiple metal shielding layers 52 and the cold plate 51 to connect with the needle tip, it is necessary to select coaxial cables of different materials in order to minimize heat conduction in the temperature gradient.

[0094] In one embodiment, the coaxial cable running from room temperature to the first cold plate 511 is a stainless steel semi-steel coaxial cable, the coaxial cable running from the first cold plate 511 to the second cold plate 512 is a stainless steel semi-steel coaxial cable, the coaxial cable running from the second cold plate 512 to the third cold plate 513 is a niobium-titanium superconducting alloy coaxial cable, and the coaxial cable running from the third cold plate 513 to the scanning component is an oxygen-free copper semi-steel coaxial cable. One end of the oxygen-free copper semi-steel coaxial cable is connected to the needle tip via an oxygen-free copper flexible coaxial cable. The flexible connection ensures the normal movement of the needle tip.

[0095] In one embodiment, multiple cold plates 51 are fixed to each other by infusion pipes 54, and the infusion pipes 54 pass through multiple metal shielding layers, and the infusion pipes 54 transmit heat-conducting medium. The scanning component 90 is connected to the base 70, and multiple metal shielding layers 52 surround the base 70. The base 70 is connected to the cold plate 51 via a spring part 53, or the scanning component 90 is connected to the cold plate 51 via a spring part 53.

[0096] In order to achieve the cooling of the cold plate 51, multiple cold plates 51 are interconnected through liquid inlet pipe 54, and the liquid inlet pipe 54 is connected to the output end of the refrigeration unit or the output end of the dilution refrigeration unit. The output heat transfer medium flows in the liquid inlet pipe 54. By controlling the flow rate and velocity, and through the cold conduction of the cold plate 51, the temperature control of the shielded space with different temperatures is achieved.

[0097] In another embodiment, the base 70 is suspended on the inner cold plate 51 by the spring part 53. When the scanning tunneling microscope device that realizes electron spin resonance detection vibrates, the spring reduces the impact of vibration on the detection environment, thereby improving the accuracy of detection.

[0098] It should be noted that the spring part 53 can be a spring.

[0099] like Figure 4 As shown, a plurality of connecting pillars are spaced apart on the base 70, and the connecting pillars are connected to the third cold plate 513 by a spring part 53.

[0100] In another embodiment, the scanning component 90 is connected to the third cold plate 513 via a spring portion 53.

[0101] In one embodiment, a temperature sensor 35 is provided on one side of the cold plate 51 and a temperature sensor 35 is provided on one side of the superconducting electromagnet assembly 71. The multiple temperature sensors 35 are configured to provide feedback on temperature changes in order to adjust the heat transfer efficiency of the heat transfer medium.

[0102] like Figure 1 As shown, a temperature sensor 35 is provided on one side of the cold plate 51 so that the temperature of the cold plate 51 can be measured by the temperature sensor 35. In this way, when the temperature of the cold plate 51 changes relative to the set temperature, the temperature can be controlled by controlling the output and output efficiency of the heat transfer medium-free refrigerator or the dilution refrigerator.

[0103] The temperature sensor on one side of the magnet assembly is used to sense temperature changes on that side of the magnet assembly, thereby ensuring the normal operation of the magnet assembly.

[0104] Furthermore, a temperature sensor is also provided on the base 70. This temperature sensor is used to detect the sample temperature and transmit the sample temperature information to the main unit 10. By analyzing and judging the sample temperature information, the output and output efficiency of the heatless refrigerator or dilution refrigerator are adjusted and controlled, thereby facilitating temperature regulation.

[0105] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A scanning tunneling microscope device for realizing electron spin resonance detection, characterized in that, include: A base on which a needle tip is provided, the needle tip being configured such that a tunneling current is generated between the needle tip and a sample on the base through a quantum tunneling effect; A microwave excitation assembly, comprising a microwave signal generating and modulation structure and an antenna, wherein the antenna is disposed on one side of the base, and the microwave excitation assembly transmits microwave signals to the antenna and / or the tip; A superconducting electromagnet assembly, wherein the superconducting electromagnet assembly is configured such that the magnetic field of the superconducting electromagnet assembly is concentrated and distributed between the needle tip and the sample; The microwave radiation from the antenna is directed toward the needle tip and the sample.

2. The scanning tunneling microscope device for realizing electron spin resonance detection as described in claim 1, characterized in that, The microwave generation and modulation structure includes a microwave signal source, which is connected to the needle tip via a first path and to the antenna via a second path.

3. The scanning tunneling microscope device for realizing electron spin resonance detection as described in claim 2, characterized in that, The first path is connected to a first impedance matching section and a third impedance matching section, and the second path is connected to a second impedance matching section and a fourth impedance matching section.

4. The scanning tunneling microscope device for realizing electron spin resonance detection as described in claim 2, characterized in that, The scanning tunneling microscope device for realizing electron spin resonance detection also includes a main unit, the tip is directly facing the sample on the base, the main unit is connected to the tip, and the sample is connected to the main unit to form a circuit, the tunneling current is excited by the quantum tunneling effect between the tip and the sample, and is fed back to the main unit through the circuit; Wherein, a DC microwave coupler is connected to the first path, the main unit is connected to the DC microwave coupler, and the DC microwave coupler is configured such that the DC microwave coupler transmits the tunneling current, or the tunneling current and microwave, on the first path through coupling.

5. The scanning tunneling microscope device for realizing electron spin resonance detection as described in claim 4, characterized in that, The microwave generation and modulation structure further includes a waveform generator connected to the DC microwave coupler and the microwave signal source.

6. The scanning tunneling microscope apparatus for realizing electron spin resonance detection as described in claim 4, characterized in that, The scanning tunneling microscope device for realizing electron spin resonance detection also includes a scanning component driven by the piezoelectric effect. The tip is connected to the scanning component, and the scanning component is configured such that the scanning component drives the tip to move, thereby controlling the relative position between the tip and the sample.

7. The scanning tunneling microscope apparatus for realizing electron spin resonance detection as described in any one of claims 1 to 6, characterized in that, The scanning tunneling microscope device for realizing electron spin resonance detection also includes a temperature control component, which covers the base, the antenna and the tip. The temperature control component is configured to control the temperature to gradually change towards the base so that the measurement environment is in a low-temperature state.

8. The scanning tunneling microscope apparatus for realizing electron spin resonance detection as described in claim 7, characterized in that, The temperature control component includes multiple metal shielding layers and multiple cold plates. The multiple metal shielding layers are nested and connected in sequence, and a temperature shielding space is formed between two adjacent metal shielding layers. At least one cold plate is provided in each temperature shielding space.

9. The scanning tunneling microscope apparatus for realizing electron spin resonance detection as described in claim 8, characterized in that, The multiple cold plates are fixed together by infusion pipes, and the infusion pipes pass through the multiple metal shielding layers, and the infusion pipes transmit heat-conducting medium; The scanning component is connected to the base, and the base is wrapped with multiple metal shielding layers. The base is connected to the cold plate via a spring, or the scanning component is connected to the cold plate via a spring.

10. The scanning tunneling microscope apparatus for realizing electron spin resonance detection as described in claim 8, characterized in that, A temperature sensor is provided on one side of the cold plate, and a temperature sensor is provided on one side of the superconducting electromagnet assembly. The multiple temperature sensors are configured to provide feedback on temperature changes in order to adjust the heat transfer efficiency of the heat transfer medium.

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