CN110085664B - High-frequency rectifying device based on superconducting intrinsic junction array - Google Patents

Abstract

The invention discloses a high-frequency rectifier device based on a superconducting intrinsic junction array in the technical field of rectifier devices, and aims to solve the technical problem that the use of diodes for rectification in the prior art is greatly limited by operating frequency and temperature. The device includes a substrate substrate parallel to the horizontal magnetic field, two electrodes are arranged on the substrate substrate, and several groups of positive asymmetric junctions are arranged between the two electrodes to form a complementary symmetrical structure and the upper surface is parallel to the substrate substrate. The BSCCO single crystal with the face boundary shape and the BSCCO single crystal with the reverse asymmetric junction shape have the CuO layer parallel to the substrate. BSCCO single crystals with symmetrical junction boundary shapes are connected through a lower BSCCO single crystal connection layer or an upper BSCCO single crystal connection layer, and both the lower BSCCO single crystal connection layer and the upper BSCCO single crystal connection layer are arranged at intervals.

Description

A high frequency rectifier device based on superconducting intrinsic junction array

technical field

The invention relates to a high-frequency rectifier device based on a superconducting intrinsic junction array, and belongs to the technical field of rectifier devices.

Background technique

Rectification is a physical phenomenon that refers to the difference in magnitude of forward and reverse currents driven by the same driving force. In power electronics, the unidirectional conductivity of diodes is most commonly used for rectification, which converts alternating current to direct current.

Whether the diode can rectify normally is restricted by factors such as operating frequency and temperature. Among the diodes, the Schottky diode has the highest operating frequency, which is a high-speed rectifier device and can reach up to 100GHz; for the AC input significantly exceeding 100GHz, the existing diode cannot rectify normally. The normal working junction temperature of various types of non-superconducting diodes is about -65°C, or 208K; in low-temperature environments where the temperature is significantly lower than this temperature, such as deep space environments, non-superconducting diodes will not work properly.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a high-frequency rectifier device based on a superconducting intrinsic junction array, comprising a substrate substrate parallel to the horizontal magnetic field, and two electrodes are arranged on the substrate substrate, Several groups of BSCCO single crystals with a forward asymmetric junction boundary shape and a reverse asymmetric junction boundary shape are arranged between the two electrodes to form a complementary symmetrical structure and the upper surface is parallel to the substrate substrate. The CuO layer in the BSCCO single crystal with the asymmetric junction boundary shape and the BSCCO single crystal with the reverse asymmetric junction boundary shape is both parallel to the substrate. The BSCCO single crystals with the boundary shape of the reverse asymmetric junction are connected through the lower BSCCO single crystal connection layer or the upper BSCCO single crystal connection layer, and the lower BSCCO single crystal connection layer and the upper BSCCO single crystal connection layer are arranged at intervals.

Further, the value range of the thickness of the BSCCO single crystal with the forward asymmetric junction boundary shape or/and the BSCCO single crystal with the reverse asymmetric junction boundary shape is [0.5, 10] μm.

Further, the thickness of the lower BSCCO single crystal connection layer or/and the upper BSCCO single crystal connection layer is less than a quarter of the thickness of the BSCCO single crystal with the forward asymmetric junction boundary shape and the BSCCO single crystal with the reverse asymmetric junction boundary shape a thickness.

Further, the value range of the plane area of the BSCCO single crystal with the forward asymmetric junction boundary shape or/and the BSCCO single crystal with the reverse asymmetric junction boundary shape is [50, 1000] μm ² .

Further, the junction shape of the BSCCO single crystal with the forward asymmetric junction boundary shape or/and the BSCCO single crystal with the reverse asymmetric junction boundary shape includes an isosceles triangle.

Further, the value range of the horizontal magnetic field strength is [0.01, 1.0]T.

Further, the substrate substrate material is MgO, silicon, sapphire or LaAlO ₃ .

Further, the electrode material is a metal thin film covering the lower BSCCO single crystal connection layer, and the metal includes gold or silver.

Compared with the prior art, the present invention achieves the beneficial effects: it can work in an extremely low temperature environment slightly higher than zero Kelvin, the rectification frequency ranges from 0Hz to about 150GHz, and its minimum operating temperature and maximum rectification frequency both exceed The index range of traditional rectifier diodes, including Turkey diodes, has broad application prospects in superconducting integrated circuits, superconducting quantum computing, and deep space and extremely low temperature environments.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the principle analysis schematic diagram of the present invention;

3 is a circuit diagram of an embodiment of the present invention;

Fig. 4 is the alternating current waveform diagram of the embodiment of the present invention;

FIG. 5 is an oscilloscope display diagram of an embodiment of the present invention.

In the figure: 1. Substrate; 2. BSCCO single crystal with forward asymmetric junction boundary shape; 3. BSCCO single crystal with reverse asymmetric junction boundary shape; 4. Lower BSCCO single crystal connection layer; 5 , upper BSCCO single crystal connection layer; 6, electrode; 7, horizontal magnetic field; 8, AC power supply; 9, superconducting intrinsic junction array rectifier device; 10, parallel resistance; 11, series resistance; 12, oscilloscope.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and cannot be used to limit the protection scope of the present invention.

It should be noted that, in the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer" and the like indicate the orientation or position The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. The terms "front", "rear", "left", "right", "upper" and "lower" used in the description of the present invention refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to is the direction toward or away from the geometric center of a particular part.

As shown in Figure 2, it is a schematic diagram of the principle analysis of the present invention. In the case of an external magnetic field, the external magnetic field easily enters the junction from the sharp corner of the junction to form a Josephson magnetic flux and moves, but it is difficult to enter the junction from the long side of the junction. The magnetic flux moves in parallel. In the figure, the magnetic flux in the isosceles triangle junction is easy to move from the top sharp corner to the bottom long side, but it is difficult to move from the bottom long side to the top sharp corner. Macroscopically, the junction is positive and negative. The superconducting critical current is asymmetrical, the superconducting critical current Ic ₁ in one direction is large, and the superconducting critical current Ic ₂ in the other direction is small, so as to realize the rectifying effect of the current;

The maximum rectification frequency of the superconducting Josephson junction magnetic flux rectifier device is proportional to the fastest moving speed of the Josephson magnetic flux in the junction. Swihart velocity), for HTS intrinsic junction, due to its high Josephson plasma oscillation frequency, the phase velocity of electromagnetic wave radiation will also be high, so in theory, the highest rectification of HTS intrinsic junction magnetic flux rectifier devices Frequency up to 150GHz.

As shown in Figure 1, it is a schematic diagram of the overall structure of the present invention, a high-frequency rectifier device based on a superconducting intrinsic junction array, comprising a substrate substrate 1 parallel to the horizontal magnetic field 7, and the material of the substrate substrate 1 can be selected from MgO , silicon, sapphire or LaAlO ₃ , and its surface is covered with a layer of insulating glue.

Two electrodes 6 are arranged on the substrate substrate 1, and several groups of BSCCO single crystals 2 with a forward asymmetric junction boundary shape and BSCCO single crystals 3 with a reverse asymmetric junction boundary shape are arranged between the two electrodes 6. Set of BSCCO single crystal 2 with forward asymmetric junction boundary shape and BSCCO single crystal 3 with reverse asymmetric junction boundary shape, including a BSCCO single crystal 2 with forward asymmetric junction boundary shape and a reverse asymmetric junction boundary shape The BSCCO single crystal 3 with the shape of the junction boundary forms a complementary symmetrical structure between the two, that is, the thickness, shape and area are the same, and the relative position is rotated horizontally by 180°;

The CuO layer in the BSCCO single crystal 2 with the forward asymmetric junction boundary shape and the BSCCO single crystal 3 with the reverse asymmetric junction boundary shape, that is, the junction surface of the BSCCO single crystal intrinsic junction, are both parallel to the substrate substrate 1 and the upper surface of BSCCO single crystal 2 with forward asymmetric junction boundary shape 2 and BSCCO single crystal 3 with reverse asymmetric junction boundary shape; the BSCCO single crystal with isosceles triangle junction shape is used in this example, but It is not limited to the isosceles triangle junction shape, as long as the boundary of the BSCCO single crystal junction perpendicular to the horizontal magnetic field 7 is obviously asymmetrical, for example, the isosceles triangle junction BSCCO single crystal can be replaced with a unilateral Zigzag BSCCO single crystal, or replace the vertex of an isosceles triangle with multiple serrated sharp corners at the top of a unilateral zigzag;

The thickness of the BSCCO single crystal 2 with the forward asymmetric junction boundary shape and the BSCCO single crystal 3 with the reverse asymmetric junction boundary shape can be adjusted, and the minimum thickness should not be less than 0.5 μm, because too thin thickness will greatly reduce the device. At the same time, the maximum thickness should not be higher than 10 μm, because too thick thickness will significantly increase the thermal effect inside the BSCCO intrinsic junction, resulting in BSCCO single crystal The temperature of the different CuO layers is inconsistent, which in turn causes the disorder of the junction voltage and current;

The junction plane area of BSCCO single crystal 2 with forward asymmetric junction boundary shape and BSCCO single crystal 3 with reverse asymmetric junction boundary shape can be adjusted, and the minimum should not be lower than 50μm ² , because too small junction area will lead to If the amplitude of the junction voltage and current is too small, the rectification effect of the device is not obvious; at the same time, the maximum area should not be higher than 1000μm ² , because the junction area is too large, which will weaken the asymmetric barrier effect of the single crystal junction boundary. The magnetic flux movement in the central part of the junction cannot be affected.

Between the adjacent BSCCO single crystal 2 of the forward asymmetric junction boundary shape and the BSCCO single crystal 3 of the reverse asymmetric junction boundary shape, through the lower BSCCO single crystal connection layer 4 and the upper BSCCO single crystal connection layer 5. For one connection, the lower BSCCO single crystal connection layer 4 and the upper BSCCO single crystal connection layer 5 are set at intervals; the thicknesses of the lower BSCCO single crystal connection layer 4 and the upper BSCCO single crystal connection layer 5 can be adjusted, but need to be smaller than the forward direction A quarter thickness of BSCCO single crystal 2 with asymmetric junction boundary shape and BSCCO single crystal 3 with reverse asymmetric junction boundary shape, because more than a quarter thickness will weaken the rectification effect of the intrinsic junction asymmetric boundary .

The material of the two electrodes 6 is a metal film covering the lower BSCCO single crystal connection layer 4 , and the metal includes gold or silver.

The horizontal magnetic field 7 can be obtained by a Helmholtz coil or a large horseshoe magnet. The size of the horizontal magnetic field 7 can be adjusted. The rectification effect is not obvious; its maximum should not be higher than 1.0T, because the magnetic field is too large, which will lead to too many magnetic fluxes in the intrinsic junction, and the interaction force between the magnetic flux and the magnetic flux is too strong, which weakens the junction boundary to the magnetic field in the junction. The influence of movement.

The present invention will be further described below with reference to the examples. In the examples, the BSCCCO single crystal rectifier device with an isosceles triangle junction shape is used.

As shown in FIG. 3 , it is a circuit diagram of an embodiment of the present invention, including a superconducting intrinsic junction array rectifier device 9 , a parallel resistor 10 connected in parallel with it, and a series resistor 11 connected in series with it. Both the parallel resistor 10 and the series resistor 11 are 10 Ohm, the two ends of the parallel resistance 10 are connected with an oscilloscope 12, the alternating current power supply 8 sends out a sinusoidal current Is with a frequency of about 50Hz, and the maximum current amplitude is 1mA, as shown in Figure 4, which is an alternating current waveform diagram of an embodiment of the present invention;

The superconducting intrinsic junction array rectifier device 9 is placed in 77K liquid nitrogen, and the horizontal magnetic field 7 provided by the energized solenoid is applied, and its size is about 0.01T; The length is 20 μm and the apex angle is 40°; at a temperature of 77K, the superconducting critical current of the superconducting intrinsic junction array rectifier device 9 shows obvious asymmetry under positive and negative currents, and the superconducting critical current Ic ₁ at positive currents is 400μA, and the superconducting critical current Ic ₂ is 1200μA at negative current;

In the positive current part, when the current is less than 400μA, that is, less than Ic ₁ , the intrinsic junction is in a superconducting state, the resistance value is zero, the parallel resistance 10 is short-circuited due to the zero resistance of the intrinsic junction, no current I _d flows, the oscilloscope 12 shows no voltage value or zero voltage value; when the current value is greater than 400μA, the intrinsic junction is in a non-superconducting state and has a certain resistance value called the normal resistance of the Josephson junction. At this moment, a current I _d flows through the parallel resistor 10 , and the magnitude of the current I _d changes with the current emitted by the AC power source 8 , and the oscilloscope 12 displays a voltage.

In the negative current part, since the maximum current from the AC power source 8 is 1000 μA, which is less than Ic ₂ =1200 μA, the superconducting junction is always in the superconducting state and the resistance is zero. At this time, the parallel resistor 10 is short-circuited and no current I _d flows. However, the oscilloscope 12 shows no voltage value or zero voltage value.

More specifically, as shown in FIG. 5 , which is an oscilloscope display diagram of an embodiment of the present invention, only the I _d component of the positive current flowing through the parallel resistor 10 forms the rectification effect on the input alternating current I _s .

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, several improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (8)

1. A high-frequency rectifying device based on a superconducting intrinsic junction array is characterized by comprising a substrate (1) parallel to a horizontal magnetic field (7), two electrodes (6) are arranged on the substrate (1), a plurality of groups of BSCCO single crystals (2) which form a complementary symmetric structure and have upper surfaces parallel to the forward asymmetric junction surface boundary shape and BSCCO single crystals (3) in a reverse asymmetric junction surface boundary shape are arranged between the two electrodes (6), CuO layers in the BSCCO single crystals (2) in the forward asymmetric junction surface boundary shape and the BSCCO single crystals (3) in the reverse asymmetric junction surface boundary shape are both parallel to the substrate (1), the BSCCO single crystals (2) in the adjacent forward asymmetric junction surface boundary shape and the BSCCO single crystals (3) in the reverse asymmetric junction surface boundary shape are connected through a lower BSCCO single crystal connecting layer (4) or an upper BSCCO single crystal connecting layer (5), the lower BSCCO single crystal connecting layer (4) and the upper BSCCO single crystal connecting layer (5) are arranged at intervals;

the thickness of the BSCCO single crystal (2) with the shape of the positive asymmetric junction surface boundary and the BSCCO single crystal (3) with the shape of the negative asymmetric junction surface boundary is in a value range of [ 0.5, 10 ] mu m;

the thickness of the lower BSCCO single crystal connecting layer (4) and the upper BSCCO single crystal connecting layer (5) is less than one fourth of the thickness of the BSCCO single crystal (2) in the shape of the boundary of the forward asymmetric junction surface and the BSCCO single crystal (3) in the shape of the boundary of the reverse asymmetric junction surface;

the intensity of the horizontal magnetic field (7) is in the range of [ 0.01, 1.0 ] T.

2. The superconducting intrinsic junction array-based high-frequency rectifying device according to claim 1, wherein the junction plane area of the forward asymmetric junction boundary-shaped BSCCO single crystal (2) and the reverse asymmetric junction boundary-shaped BSCCO single crystal (3) ranges from [ 50, 1000 ] μm²。

3. The superconducting intrinsic junction array-based high-frequency rectifying device according to claim 1, wherein the junction surface shapes of the forward asymmetric junction surface boundary shaped BSCCO single crystal (2) and the reverse asymmetric junction surface boundary shaped BSCCO single crystal (3) comprise isosceles triangles.

4. A high-frequency rectifying device based on superconducting intrinsic junction array according to any of claims 1 to 3, characterized in that the substrate (1) is MgO.

5. A high-frequency rectifying device based on superconducting intrinsic junction array according to any of claims 1 to 3, characterized in that the substrate (1) is made of silicon.

6. A high-frequency rectifying device based on superconducting intrinsic junction array according to any of claims 1 to 3, characterized in that the substrate (1) is made of sapphire.

7. A high-frequency rectifying device based on superconducting intrinsic junction array according to any of claims 1 to 3, characterized in that the substrate (1) is LaAlO₃。

8. A high-frequency rectifying device based on superconducting intrinsic junction array according to any of claims 1 to 3, characterized in that the electrode (6) is a thin film of metal, including gold or silver, overlying the underlying BSCCO single crystal connection layer (4).

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