Superconducting diode device based on single-layer niobium nitride nanoring and control method thereof

Abstract

The application discloses a superconducting diode device based on a single-layer niobium nitride nanoring and a control method thereof, and belongs to the technical field of superconducting electronics. The superconducting diode device comprises an insulating substrate and a niobium nitride layer. The niobium nitride layer comprises a first working line, a second working line and an intermediate ring. The first working line comprises a first line segment, a second line segment and a first intermediate part. The second working line comprises a third line segment, a fourth line segment and a second intermediate part. The intermediate ring is connected with the first intermediate part and the second intermediate part. The application uses a single-layer niobium nitride film, and realizes a structure of a superconducting diode with a minimum size and a single layer by means of the action of a nanoring with geometric asymmetry and an external magnetic field. The device size is greatly reduced, which is conducive to high-density integration and miniaturization application, and conducive to realizing low-power consumption and high-speed rectification control. The difficulty of material and interface control is greatly reduced. The process flow is simple and has good repeatability, which is conducive to reducing the preparation cost and improving the consistency of the device.

Description

Technical Field

[0001] This invention belongs to the field of superconducting electronics technology, specifically relating to a superconducting diode device based on a single-layer niobium nitride nanoring and its control method. Background Technology

[0002] A superconducting diode is a superconducting electronic device with non-reciprocal current characteristics. It exhibits different critical currents under forward and reverse currents, thus realizing unidirectional supercurrent transport and possessing broad application potential. In the fields of low-temperature superconducting electronics and quantum computing, superconducting diodes are considered crucial fundamental components. Traditional superconducting diodes typically rely on complex multilayer structures, magnetic materials, or Josephson junctions, resulting in cumbersome manufacturing processes and large device sizes, hindering large-scale application in integrated circuits. In recent years, with the development of nanotechnology, researchers have begun exploring the fabrication of highly efficient superconducting diodes by designing simplified structures. For example, using geometrically asymmetric nanoring structures to break spatial inversion symmetry and combining this with an external magnetic field to break time reversal symmetry, thereby achieving non-reciprocal superconducting current. However, these techniques mostly rely on complex multilayer materials or materials with specific physical properties (such as bonding with magnetic materials, multilayer thin-film corner structures, introducing defects, etc.), leading to scalability and cost issues in practical applications. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a superconducting diode device based on a single-layer niobium nitride nanoring. This device uses a single-layer niobium nitride thin film to form a superconducting diode structure with extremely small size and a single layer. The invention also provides a control method for the superconducting diode device based on a single-layer niobium nitride nanoring, which combines an external magnetic field to break the time reversal symmetry, thereby achieving the non-reciprocity of superconducting current.

[0004] Technical Solution: To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A superconducting diode device based on a single-layer niobium nitride nanoring includes an insulating substrate and a niobium nitride layer disposed on the insulating substrate. The niobium nitride layer includes a first working line, a second working line symmetrically disposed with respect to the first working line, and an intermediate ring connecting the first working line and the second working line. The first working line includes a first segment, a second segment connected to the first segment, and a first intermediate portion connected between the first segment and the second segment. The second working line includes a third segment, a fourth segment connected to the third segment, and a second intermediate portion connected between the third segment and the fourth segment. The intermediate ring is connected to the first intermediate portion and the second intermediate portion.

[0006] Preferably, the linewidth of the first line segment is W1, 500nm≤W1≤1000nm; the linewidth of the second line segment is W2, 500nm≤W2≤1000nm; the linewidth of the third line segment is W3, 500nm≤W3≤1000nm; and the linewidth of the fourth line segment is W4, 500nm≤W4≤1000nm.

[0007] Preferably, the insulating substrate includes a silicon substrate and a silicon dioxide thin film disposed on the silicon substrate. The thickness of the insulating substrate is t1, 400μm≤t1≤600μm, the thickness of the silicon dioxide thin film is t2, 200nm≤t2≤300nm, and the thickness of the niobium nitride layer is t3, 8nm≤t3≤12nm.

[0008] Preferably, the intermediate ring has a notch, a second intermediate groove is formed between the first working line and the second working line, a first intermediate groove is formed inside the intermediate ring, and the first intermediate groove is connected to the second intermediate groove through the notch on the intermediate ring.

[0009] Preferably, the outer diameter of the intermediate ring is d2, the inner diameter of the intermediate ring is d3, and 80nm≤d2-d3≤150nm.

[0010] The present invention also provides a control method for the above-mentioned superconducting diode device based on a single-layer niobium nitride nanoring, comprising the following steps:

[0011] Step 1: Place the superconducting diode at a temperature of X1K and an external magnetic field of BGs;

[0012] Step 2: Apply a direct current to the superconducting diode, with a maximum direct current of 250μA;

[0013] Step 3: The diode effect is generated, and the superconducting current conducts in one direction, realizing the unidirectional transmission of the superconducting current;

[0014] Step 4: Reverse the direction of the external magnetic field to generate a diode effect, enabling unidirectional transmission of the superconducting current, and the direction of conduction is opposite to that in Step 3.

[0015] Preferably, 2≤X1≤8, 100≤|B|≤2000.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0017] 1. By using a single-layer niobium nitride thin film and leveraging the geometric asymmetry of nanorings and the effect of an external magnetic field, a superconducting diode structure with extremely small size and single layer is achieved. This greatly reduces the device size, which is beneficial for high-density integration and miniaturization applications, and facilitates low-power, high-speed rectification control.

[0018] 2. Based on a single-layer superconducting thin film, the structure is simplified. The entire device (including the nanoring and the electrode) is fabricated from the same NbN thin film, eliminating the need for multi-layer stacking or the introduction of complex heterostructures such as magnetic materials, thereby significantly reducing the difficulty of material and interface control.

[0019] 3. Compact all-planar nanoring design, compatible with standard processes. The device adopts a completely planar nanoring architecture, which is not only compact in structure, but also fully compatible with current standard photolithography processes, which facilitates manufacturing and superconducting circuit integration, and has good scalability and industrialization potential.

[0020] 4. Simple fabrication process and low manufacturing cost. Compared with traditional methods that rely on Josephson junctions, magnetic layers, or complex epitaxial growth, this invention can be completed simply through single-layer thin film patterning and electrode fabrication. The process is simple, has good repeatability, and helps to reduce fabrication costs and improve device consistency. Attached Figure Description

[0021] Figure 1 This is an enlarged view of the superconducting diode device according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the intermediate ring structure in the embodiment;

[0023] Figure 3 This is a schematic diagram of the cross-sectional structure of the insulating substrate and niobium nitride layer in the embodiment;

[0024] Figure 4 This is a wiring diagram for measuring the superconducting diode device in an embodiment;

[0025] Figure 5 These are schematic diagrams of the structures of two superconducting diode devices in the embodiment;

[0026] Figure 6 This is a schematic diagram of a superconducting diode device structure according to an embodiment;

[0027] Figure 7 This is an example of the IV characteristic curve of a superconducting diode measured at a temperature of 2K and an external magnetic field of +760Gs.

[0028] Figure 8 This is an example of the IV characteristic curve of a superconducting diode measured at a temperature of 2K and an external magnetic field of -760Gs.

[0029] Figure 9 This is a graph showing the dependence of the critical current of a superconducting diode on the magnetic field at a temperature of 2K and an external magnetic field of -2KGs to +2KGs.

[0030] Figure 10This example demonstrates the non-reciprocity of the critical current of a superconducting diode under conditions of 2K temperature and an external magnetic field of -2KGs to +2KGs. Dependence curve on magnetic field;

[0031] Figure 11 This is a graph showing the dependence of the diode efficiency (η) of a superconducting diode on the magnetic field at a temperature of 2K and an external magnetic field of -2KGs to +2KGs.

[0032] Figure 12 This is a square wave signal diagram of the input superconducting diode in the embodiment;

[0033] Figure 13 In this embodiment, the superconducting diode operates at a temperature of 2K and an external magnetic field of -760Gs. Figure 12 The switching characteristics of the device under a square wave signal;

[0034] Figure 14 In this embodiment, the superconducting diode operates at a temperature of 2K and an external magnetic field of +760Gs. Figure 12 The switching characteristics of the device under a square wave signal. Detailed Implementation

[0035] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0036] Example 1

[0037] like Figure 1 and Figure 3 As shown, a superconducting diode device based on a single-layer niobium nitride nanoring includes an insulating substrate 1 and a niobium nitride (NbN) layer disposed on the insulating substrate 1. The insulating substrate 1 includes a silicon substrate 11 and a silicon dioxide thin film 12 disposed on the silicon substrate 11. The thickness of the insulating substrate 1 is t1, 400μm≤t1≤600μm, and in this embodiment t1=500±10μm. The thickness of the silicon dioxide thin film 12 is t2, 250nm≤t2≤300nm, and in this embodiment t2=285nm. In this embodiment, the insulating substrate 1 adopts an existing thermally oxidized silicon substrate, and the structure is a silicon wafer with a layer of silicon oxide on it.

[0038] like Figure 1 , Figure 2 , Figure 3 and Figure 5As shown, the niobium nitride layer thickness is t3, where 8nm ≤ t3 ≤ 12nm, and in this embodiment, t3 = 10nm. The niobium nitride layer includes a first working line 21, a second working line 23 symmetrically arranged with respect to the first working line 21, and an intermediate ring 22 connecting the first working line 21 and the second working line 23. The first working line 21 includes a first segment 211, a first intermediate portion 212, and a second segment 213. The first intermediate portion 212 connects the first segment 211 and the second segment 213 and is right-angled. The second segment 213 is perpendicularly connected to the first segment 211 through the first intermediate portion 212. The second working line 23 includes a third segment 231 and a second intermediate portion 232. 32 and the fourth line segment 233, the second middle part 232 is connected between the third line segment 231 and the fourth line segment 233, the second middle part 232 is right angled, the fourth line segment 233 is perpendicularly connected to the third line segment 231 through the second middle part 232, the middle ring 22 is connected to the first middle part 212 and the second middle part 232, the four line segments are four electrodes, the second line segment 213 is used to connect to the positive current I+, the fourth line segment 233 is used to connect to the negative current I-, the first line segment 211 is used to connect to the positive voltage V+, and the third line segment 231 is used to connect to the negative voltage V-.

[0039] like Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, the niobium nitride layer also includes an enlarged electrode section, which is disposed on the outer periphery of the first working line 21 and the second working line 23. The enlarged electrode section includes a first connection point 31, a second connection point 32, a third connection point 33, and a fourth connection point 34. The first line segment 211 is connected to the first connection point 31, the second line segment 213 is connected to the second connection point 32, the third line segment 231 is connected to the fourth connection point 34, and the fourth line segment 233 is connected to the third connection point 33. The enlarged electrode section on the outer periphery (e.g. Figure 3 , Figure 4 and Figure 5 As shown, Figure 1 yes Figure 6The enlarged view of the area within the red box shows the light yellow box and the gray area extending towards the center, which is the expanded electrode area. The blue area represents the exposed silicon dioxide film after patterning. These four connection points are used to expand the ends of the first working line 21 and the second working line 23. All four connection points are square (or rectangular, circular, or other shapes). In this embodiment, the connection point size is 500μm × 500μm. These four connection points increase the thickness of the niobium nitride film at that location (the niobium nitride film is only 10nm thick; wire bonding would penetrate the film), facilitating wire bonding and subsequent testing. The connection points include a titanium (Ti) layer and a gold (Au) layer. The titanium layer serves as an adhesion layer with a thickness of 10nm, and the gold layer is used for wire bonding with a thickness of 80nm. In this embodiment, the two superconducting diode devices are arranged vertically to improve manufacturing efficiency.

[0040] like Figure 1 and Figure 2 As shown, the line width of the first segment 211 is W1, 500nm≤W1≤1000nm; the line width of the second segment 213 is W2, 500nm≤W2≤1000nm; the line width of the third segment 231 is W3, 500nm≤W3≤1000nm; and the line width of the fourth segment 233 is W4, 500nm≤W4≤1000nm. In this embodiment, the widths of the first segment 211, the second segment 213, the third segment 231, and the fourth segment 233 are all equal, 900nm, and the width of all four segments is greater than the outer diameter of the intermediate ring 22.

[0041] The intermediate ring 22 forms a nanoring with a notch. The arc length of the notch is C1, and the circumference of the intermediate ring 22 is C2, where C1 < 0.25C2. A second intermediate groove 102 is formed between the first working line 21 and the second working line 23. A first intermediate groove 101 is formed inside the intermediate ring 22. The width of the second intermediate groove 102 is the distance between the first working line 21 and the second working line 23. In this embodiment, the width of the second intermediate groove 102 is 310 nm. The first intermediate groove 101 is connected to the second intermediate groove 102 through the notch on the intermediate ring 22.

[0042] like Figure 2 As shown, the outer diameter of the intermediate ring 22 is d2, 500nm≤d2≤800nm, and the inner diameter of the intermediate ring 22 is d3, 350nm≤d3≤650nm, and 80nm<d2-d3<150nm. In this embodiment, d2-d3=118nm, d2=600nm, and d3=482nm.

[0043] This embodiment also provides a control method for a superconducting diode device based on a single-layer niobium nitride nanoring, including the following steps:

[0044] Step 1: Place the superconducting diode at a temperature of X1K and an external magnetic field of BGs; 2≤X1≤8, 100≤|B|≤2000.

[0045] Step 2: Apply a direct current to the superconducting diode, with a maximum direct current of 250μA;

[0046] The positive terminal of the current source is connected to the second segment 213, and the negative terminal is connected to the fourth segment 233. Current is applied in the following sequence: 0→250μA, 250μA→-250μA, -250μA→0. This cycle repeats from 0 to the maximum positive current value (250μA), then from the maximum positive current value to the maximum negative current value (-250μA), and then back to 0. During this cycle, the superconducting diode's state changes as follows: superconducting state to normal state (0→250μA), normal state to superconducting state, then back to normal state (250μA→-250μA), and then back to superconducting state (-250μA→0). Figure 7 and Figure 8 The IV curve of the test.

[0047] Step 3: The diode effect is generated, and the superconducting current conducts in one direction, realizing the unidirectional transmission of the superconducting current;

[0048] In this embodiment, the device was placed at a temperature of 2K and a magnetic field of +760Gs, and a current-voltage test was performed on the device, such as... Figure 7 As shown, the results indicate that the device exhibits significant critical current non-reciprocity when an out-of-plane magnetic field BGs is applied. When the current I is... Within the range, where, It represents the positive critical current (the critical current when the current is swept forward, that is, when the current changes from 0 to 250μA. The critical current refers to the current magnitude corresponding to the transition of the device from the superconducting state to the normal state). This represents the negative critical current (the critical current when the current is swept negatively, i.e., when the current changes from 0 to -250 μA). Charge transport in the positive current direction is dominated by ordinary electrons, while in the opposite direction it is dominated by superconducting Cooper pairs. This leads to unidirectional supercurrent transport, demonstrating the superconducting diode effect.

[0049] Step 4: Reverse the direction of the external magnetic field to generate a diode effect, enabling unidirectional transmission of the superconducting current, and the direction of conduction is opposite to that in Step 3.

[0050] In this embodiment, the device was placed at a temperature of 2K and a magnetic field of -760Gs, and a current-voltage test was performed on the device. Figure 8 As shown, the results demonstrate that the device exhibits significant non-reciprocity of positive and negative critical currents when an out-of-plane magnetic field BGs is applied. When the current I is in Within this range, charge transport in the positive current direction is dominated by superconducting Cooper pairs, while in the opposite direction it is dominated by ordinary electrons. This leads to unidirectional supercurrent transport, demonstrating that the polarity of the superconducting diode also reverses after the magnetic field direction is reversed.

[0051] To investigate the magnetic field dependence of the diode effect, this embodiment performed system transmission measurements at T=2K while scanning a perpendicular magnetic field. The extracted critical current... and Plotting as a function of magnetic field on Figure 9 In the finite field, the two branches exhibit obvious non-reciprocity, which contrasts sharply with their symmetric behavior in the zero field.

[0052] Size of non-reciprocity Defined as The relationship with the magnetic field is as follows: Figure 10 As shown, It increases with increasing field strength, reaches a maximum value, and then decreases, forming a condition that satisfies... The diode exhibits an antisymmetric profile. This antisymmetry reflects the reversal of diode polarity as the direction of the magnetic field reverses.

[0053] Figure 11 The relationship between the device's diode efficiency and the magnetic field is shown, exhibiting a similar field dependence and also changing sign with magnetic field reversal. At 2K, the device achieves a maximum diode efficiency of 28.1%, demonstrating strong irreversible transport in a simple monolayer niobium nitride nanoring structure.

[0054] Next, the rectified signal of the proposed device was tested by placing the device at a temperature of 2K. Figure 12 The device is represented by a periodic square wave current signal applied to it, with time on the horizontal axis and current magnitude on the vertical axis. When the external magnetic field is +760 Gs, the device exhibits clear and stable switching characteristics. Figure 14 The horizontal axis represents time, and the vertical axis represents voltage; when the external magnetic field is changed to -760Gs ( Figure 13 The switching characteristics of the device reversed, which also indicates that the switching polarity of the device reversed as the direction of the magnetic field changed.

[0055] This embodiment also provides a method for manufacturing a superconducting diode device with a single-layer niobium nitride nanoring, including the following steps:

[0056] S1. A niobium nitride layer is magnetron sputtered on an insulating substrate 1. The thickness of the niobium nitride layer is t3, where 8nm≤t3≤12nm.

[0057] In this embodiment, the insulating substrate 1 is a commercially available silicon dioxide / silicon substrate. The insulating substrate 1 is sequentially ultrasonically cleaned with acetone, alcohol, and deionized water, and then cleaned (surface cleaned) using IBE (ion milling). The gas atmosphere is Ar2, flow rate 80 sccm, pressure 0.5 mTorr, ion beam current 30 mA, and actual cleaning time 15 s. The insulating substrate 1 includes a silicon substrate 11 and a silicon dioxide thin film 12 disposed on the silicon substrate 11. The insulating substrate 1 is 3.5 mm long and 3.5 mm wide, with an overall thickness of t1 = 500 μm and a silicon dioxide thin film 12 thickness of t2 = 285 nm. A niobium nitride film is deposited on the insulating substrate 1 using magnetron sputtering, with Nb as the target material and an Ar2:N2 = 70:10 gas atmosphere. The NbN film deposited on insulating substrate 1 was nitrided under the following conditions: pressure 2.0 mTorr, current 1.05 A, actual sputtering time 10 s. The gas atmosphere was N2 with a flow rate of 50 sccm, pressure 5.0 mTorr, time 20 min, and niobium nitride layer thickness t3 = 10 nm. The niobium nitride layer formed a niobium nitride thin film.

[0058] S2. Patterning the niobium nitride layer to form an enlarged electrode portion, and forming multiple connection points on the enlarged electrode portion. The patterning includes ultraviolet lithography and reactive ion etching.

[0059] Specific process: Photoresist (such as AZ5214 series) is spin-coated onto a niobium nitride thin film. Spin-coating is divided into two steps: the first spin-coating speed is 600 rpm / min for 6 s, and the second spin-coating speed is 4000 rpm / min for 60 s, followed by pre-baking (drying on a heated stage at 95℃ for 2 min). The electrode pattern (enlarged electrode pattern) on the photomask is transferred to the niobium nitride thin film using a UV lithography machine. The exposure time is 10 s, and the developer is a positive photoresist developer with a development time of 28 s. Then, the photoresist is applied via RIE (reactive optical emission lithography). Ion etching was used to etch the niobium nitride film using SF6 and CHF3 at a pressure of 4.0 Pa, a power of 80 W, and an etching time of 38 s. The niobium nitride film was then subjected to ultrasonic stripping in acetone at a power of 40 W for 45 s. The sample was placed in a magnetron sputtering apparatus, where titanium (Ti) and gold (Au) layers were sequentially deposited at four locations on the enlarged electrode section to form four connection points. The connection point dimensions were 500 μm × 500 μm. The titanium layer served as an adhesion layer with a thickness of 10 nm, and the gold layer was used for wire bonding with a thickness of 80 nm. The patterned enlarged electrode section expanded the ends of the first working line 21 and the second working line 23, and the connection points on the enlarged electrode section facilitated wire bonding.

[0060] S3. Patterning of the niobium nitride layer to form a first working line 21, a second working line 23 and an intermediate ring 22. Patterning includes ultraviolet lithography, reactive ion etching and electron beam exposure.

[0061] Specific process: Electron beam photoresist (such as a double layer of PMMA (polymethyl methacrylate), with the bottom layer being PMMA A2 495 at a spin coating rate of 800 r / min for 10 s and the second layer being PMMA A2 950 at a spin coating rate of 2500 r / min for 60 s) is spin-coated onto the surface of the niobium nitride layer. The drying temperature is 180℃ for 4 min, and each layer of the double-layer photoresist requires drying after spin coating. The nano-ring pattern (the pattern of the first working line 21, the second working line 23, and the intermediate ring 22) is transferred onto the niobium nitride thin film using electron beam exposure, with an exposure dose of 825 μC / cm². 2 The developer was MIBK, the development time was 1 min 30 s, and the fixer was isopropanol, the fixing time was 1 min. The niobium nitride film was etched by reactive ion etching, with SF6 and CHF3 as the etching gases, a pressure of 4.0 Pa, a power of 80 W, and an etching time of 38 s. The niobium nitride film was then subjected to ultrasonic stripping in n-methyl, with an ultrasonic power of 40 W and a time of 1 min. A pattern of a first working line 21, a second working line 23, and an intermediate ring 22 was formed on the niobium nitride layer.

[0062] Test: A transmission experiment was conducted using the standard four-probe method. An input sinusoidal alternating current was applied using current source 5, such as... Figure 4 As shown, an input current is applied vertically and the output voltage is read horizontally. One wire of current source 5 is connected to the second segment 213, and the other wire is connected to the fourth segment 233. Current source 5 is a Keithley 6221 AC / DC current source. The Keithley 6221 current source is used to generate standard sinusoidal AC and DC currents. A voltmeter 6 (Keithley 2821A) is used to measure the voltage. One wire of the Keithley 2821A voltmeter 6 is connected to the first segment 211, and the other wire is connected to the third segment 231. The superconducting diode device is placed in a three-dimensional superconducting cryogenic magnet system (CMI), with the magnetic field applied perpendicular to the sample plane. Measurements are performed at various fixed temperatures, with stability within ±1 mK.

[0063] This embodiment demonstrates that a minimal superconducting diode can be realized using a single-layer NbN nanoring with engineering geometric asymmetry. Under a vertical magnetic field, the device exhibits a distinct, polarity-switchable critical current non-reciprocity. Furthermore, the compact and fully planar nanoring architecture is compatible with standard photolithography processes and scalable integration. In summary, these findings establish asymmetric superconducting nanorings as a simple and effective platform for superconducting diode devices, and provide a clear roadmap for device optimization through material selection and geometric design, tailored to the specific performance requirements of the target application. In conclusion, this invention achieves efficient, switchable superconducting diode effects while possessing significant advantages such as structural simplicity, process friendliness, and ease of integration, providing a practical technical path for the development of superconducting electronic devices and low-temperature integrated circuits.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A superconducting diode device based on a single-layer niobium nitride nanoring, characterized in that, The device includes an insulating substrate (1) and a niobium nitride layer disposed on the insulating substrate (1). The niobium nitride layer includes a first working line (21), a second working line (23) symmetrically disposed with respect to the first working line (21), and an intermediate ring (22) connecting the first working line (21) and the second working line (23). The first working line (21) includes a first line segment (211), a second line segment (213) connected to the first line segment (211), and a first intermediate portion (212) connecting the first line segment (211) and the second line segment (213). The second working line (23) includes a third line segment (23). 1) A fourth line segment (233) connected to the third line segment (231) and a second intermediate part (232) connected between the third line segment (231) and the fourth line segment (233). The intermediate ring (22) is connected to the first intermediate part (212) and the second intermediate part (232). The intermediate ring (22) has a notch. A second intermediate groove (102) is formed between the first working line (21) and the second working line (23). A first intermediate groove (101) is formed inside the intermediate ring (22). The first intermediate groove (101) is connected to the second intermediate groove (102) through the notch on the intermediate ring (22).

2. The superconducting diode device based on a single-layer niobium nitride nanoring according to claim 1, characterized in that, The first line segment (211) has a line width of W1, 500nm≤W1≤1000nm; the second line segment (213) has a line width of W2, 500nm≤W2≤1000nm; the third line segment (231) has a line width of W3, 500nm≤W3≤1000nm; and the fourth line segment (233) has a line width of W4, 500nm≤W4≤1000nm.

3. The superconducting diode device based on a single-layer niobium nitride nanoring according to claim 2, characterized in that, The insulating substrate (1) includes a silicon substrate (11) and a silicon dioxide thin film (12) disposed on the silicon substrate (11). The thickness of the insulating substrate (1) is t1, 400μm≤t1≤600μm, the thickness of the silicon dioxide thin film (12) is t2, 200nm≤t2≤300nm, and the thickness of the niobium nitride layer is t3, 8nm≤t3≤12nm.

4. The superconducting diode device based on a single-layer niobium nitride nanoring according to claim 1, characterized in that, The outer diameter of the intermediate ring (22) is d2, and the inner diameter of the intermediate ring (22) is d3, with 80nm≤d2-d3≤150nm.

5. A control method for a superconducting diode device based on a monolayer niobium nitride nanoring as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Place the superconducting diode at a temperature of X1K and an external magnetic field of BGs, where 2≤X1≤8 and 100≤|B|≤2000; Step 2: Apply a direct current to the superconducting diode, with a maximum current of 250mA; Step 3: The diode effect is generated, and the superconducting current conducts in one direction, realizing the unidirectional transmission of the superconducting current; Step 4: Reverse the direction of the external magnetic field to generate a diode effect, enabling unidirectional transmission of the superconducting current, and the direction of conduction is opposite to that in Step 3.

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