CN115666211A

CN115666211A - Superconducting quantum interferometer and preparation method thereof

Info

Publication number: CN115666211A
Application number: CN202211306367.7A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Origin Quantum Computing Technology Co Ltd
Current assignee: Origin Quantum Computing Technology Co Ltd
Priority date: 2022-10-24
Filing date: 2022-10-24
Publication date: 2023-01-31
Anticipated expiration: 2042-10-24
Also published as: CN115666211B

Abstract

The invention discloses a superconducting quantum interferometer and a preparation method thereof. The preparation method comprises the following steps: providing a substrate; forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on a substrate, wherein the first junction circuit is electrically connected with one end of the second junction circuit and the other end is open; forming conductor elements electrically connected to the other ends of the first junction circuit and the second junction circuit, respectively, on the substrate to constitute a superconducting quantum interferometer; wherein the number and/or connection relationship of the first and second josephson junctions is configured such that the equivalent resistances of the first and second junction circuits are not equal. Through the mode, the invention can prepare the superconducting quantum interferometer with nondegenerate points and higher bit frequency, thereby realizing stronger quantum information processing capability.

Description

Superconducting quantum interferometer and preparation method thereof

Technical Field

The invention relates to the field of quantum information, in particular to a superconducting quantum interferometer and a preparation method thereof.

Background

The operation of the quantum logic gate on the qubit must be completed before the qubit decoheres. The more quantum logic gate operations that can be implemented before decoherence of a qubit, the stronger the quantum information processing capability of the qubit.

Modulation of the bit frequency is one of the important ways to implement quantum logic gates. When two identical josephson junctions are connected in parallel to form a loop, the frequency of the bit can be varied by adjusting the magnetic flux in the loop. Such a loop is called a superconducting quantum interferometer, the point with the largest frequency is called Sweet point or Sweet spot, also called degenerate point, which usually possesses a high decoherence time.

However, although the frequency of the degenerate point is relatively high, the frequency of the non-degenerate point is very low in the conventional superconducting quantum interferometer, and therefore, when the degenerate point is shifted, the decoherence time of the qubit is greatly reduced. Most of the time, however, the qubit operating frequency point is not at a degenerate point.

Disclosure of Invention

The invention aims to provide a superconducting quantum interferometer and a preparation method thereof, which are used for solving the problem that the frequency of a nondegenerate point of the superconducting quantum interferometer in the prior art is very low, and can be used for preparing the superconducting quantum interferometer with the nondegenerate point and higher bit frequency, so that stronger quantum information processing capacity is realized.

In order to solve the above technical problems, the present invention provides a method for manufacturing a superconducting quantum interferometer, comprising:

providing a substrate;

forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on the substrate, wherein the first junction circuit is electrically connected with one end of the second junction circuit and the other end is open;

forming conductor elements electrically connected to the other ends of the first junction circuit and the second junction circuit, respectively, on the substrate to constitute a superconducting quantum interferometer;

wherein the number and/or connection relationship of the first and second josephson junctions is configured such that the equivalent resistances of the first and second junction circuits are not equal.

Preferably, the resistances of the first and second josephson junctions are not equal.

Preferably, the areas and/or barrier layer thicknesses of the first and second josephson junctions are not equal.

Preferably, the barrier layers of the first and second josephson junctions are equal in thickness but unequal in area.

Preferably, the number of the first josephson junction and the second josephson junction is one.

Preferably, the step of forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on the substrate includes:

forming a first superconducting wire and a second superconducting wire connected to each other on the substrate;

forming a barrier layer on surfaces of the first and second superconducting lines, and forming a third superconducting line overlapping the first superconducting line and a fourth superconducting line overlapping the second superconducting line on the substrate to form a first josephson junction at the overlap of the first superconducting line and a second josephson junction having a different area from the first josephson junction at the overlap of the second superconducting line;

wherein the first superconducting wire, the third superconducting wire and the first Josephson junction form a first junction circuit, and the second superconducting wire, the fourth superconducting wire and the second Josephson junction form a second junction circuit.

Preferably, the step of forming a first superconducting wire and a second superconducting wire connected to each other on the substrate includes:

forming a first photoresist layer on the substrate;

exposing a first channel and a second channel which are communicated with each other on the first photoresist layer;

and performing vertical evaporation on the first channel and the second channel, and respectively forming a first superconducting wire and a second superconducting wire in the first channel and the second channel.

Preferably, the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a fourth superconducting wire overlapping the second superconducting wire on the substrate includes:

stripping the first photoresist layer to form a second photoresist layer on the substrate;

exposing a third channel intersecting the first superconducting wire and a fourth channel intersecting the second superconducting wire on the second photoresist layer;

forming a barrier layer on a surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel;

and vertically evaporating the third channel and the fourth channel to form a third superconducting wire and a fourth superconducting wire in the third channel and the fourth channel respectively.

Preferably, the step of forming a first superconducting wire and a second superconducting wire electrically connected to each other on the substrate includes:

forming a photoresist layer on the substrate;

exposing a first channel and a second channel which are parallel and mutually communicated on the photoresist layer, a third channel which is vertically crossed with the first channel and a fourth channel which is vertically crossed with the second channel;

performing oblique evaporation in a direction parallel to the first channel such that a first superconducting wire and a second superconducting wire are formed only in the first channel and the second channel, respectively.

forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire;

performing oblique evaporation in a direction parallel to the third channel so that a third superconducting wire and a fourth superconducting wire are formed only in the third channel and the fourth channel, respectively.

Preferably, the number of the first josephson junctions is one, and the number of the second josephson junctions is plural.

Preferably, the plurality of second josephson junctions are connected in series.

forming a first superconducting wire and a plurality of second superconducting wires on the substrate, wherein the first superconducting wire on the outermost side is connected with the first superconducting wire;

forming barrier layers on surfaces of the first and second superconducting wires, and forming a third superconducting wire and a fourth superconducting wire on the substrate, wherein the third superconducting wire overlaps the first superconducting wire, the fourth superconducting wires overlap the second superconducting wires in a one-to-one correspondence, respectively, and each second superconducting wire further overlaps the fourth superconducting wire overlapping the previous second superconducting wire to form a first josephson junction at the overlapping of the first superconducting wires and a second josephson junction at the overlapping of the second superconducting wires;

wherein the first superconducting line, the third superconducting line and the first josephson junction constitute a first junction circuit, and the second superconducting lines, the fourth superconducting lines and the second josephson junctions constitute a second junction circuit.

Preferably, the step of forming a first superconducting wire and a plurality of second superconducting wires on the substrate includes:

forming a first photoresist layer on the substrate;

exposing a first channel and a plurality of second channels on the first photoresist layer, wherein the first channel on the outermost side is communicated with the first channel;

and vertically evaporating the first channel and the plurality of second channels to form a first superconducting wire and a second superconducting wire in the first channel and each second channel respectively.

Preferably, the step of forming a barrier layer on the surfaces of the first superconducting wire and the plurality of second superconducting wires and forming a third superconducting wire and a plurality of fourth superconducting wires on the substrate includes:

exposing a third channel intersected with the first superconducting line and a plurality of fourth channels respectively intersected with the plurality of second superconducting lines in a one-to-one correspondence manner on the second photoresist layer, wherein the fourth channel intersected with each second superconducting line is also intersected with the next second superconducting line;

and vertically evaporating the third channel and the fourth channel, and respectively forming a third superconducting wire and a fourth superconducting wire in the third channel and each fourth channel.

forming a photoresist layer on the substrate;

exposing a first channel and a plurality of second channels on the photoresist layer, as well as a third channel vertically crossed with the first channel and a plurality of fourth channels vertically crossed with the plurality of second channels respectively in one-to-one correspondence, wherein the first channel is parallel to the plurality of second channels, the first channel on the outermost side is communicated with the first channel, and each second channel is also vertically crossed with the fourth channel crossed with the previous second channel;

and performing oblique evaporation along a direction parallel to the first channel so that a first superconducting wire and a second superconducting wire are respectively formed only in the first channel and each second channel.

forming a barrier layer on the surface of the first superconducting wire and each of the second superconducting wires;

performing oblique evaporation in a direction parallel to the third channel such that third and fourth superconducting wires are formed only in the third channel and each of the fourth channels, respectively.

Preferably, the connection relationships of the plurality of second josephson junctions are in parallel.

forming a first superconducting wire and a second superconducting wire electrically connected to each other on the substrate;

forming a barrier layer on surfaces of the first and second superconducting wires, and forming a third superconducting wire overlapping the first superconducting wire and a plurality of fourth superconducting wires overlapping the second superconducting wire on the substrate to form a first josephson junction at the overlapping of the first superconducting wires and a second josephson junction at the overlapping of the second superconducting wires;

wherein the first superconducting wire, the third superconducting wire and the first josephson junction form a first junction circuit, and the second superconducting wire, the plurality of fourth superconducting wires and the plurality of second josephson junctions form a second junction circuit.

forming a first photoresist layer on the substrate;

and vertically evaporating the first channel and the second channel, and respectively forming a first superconducting wire and a second superconducting wire in the first channel and the second channel.

Preferably, the step of forming a barrier layer on the surfaces of the first and second superconducting wires and forming a third superconducting wire overlapping the first superconducting wire and a plurality of fourth superconducting wires overlapping the second superconducting wire on the substrate includes:

exposing a third channel intersected with the first superconducting wire and a plurality of fourth channels respectively intersected with the second superconducting wire on the second photoresist layer;

and performing vertical evaporation on the third channel and the fourth channel, and forming a third superconducting wire and a fourth superconducting wire in the third channel and each fourth channel respectively.

forming a photoresist layer on the substrate;

exposing a first channel and a second channel on the photoresist layer, a third channel vertically crossed with the first channel and a plurality of fourth channels vertically crossed with the second channel respectively, wherein the first channel and the second channel are parallel and communicated;

performing oblique evaporation in a direction parallel to the third channel so that a third superconducting wire and a fourth superconducting wire are formed only in the third channel and each of the fourth channels, respectively.

Preferably, before the step of forming a barrier layer on the surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel, the method further includes:

and removing the natural oxide layers on the surfaces of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel by adopting an ion beam etching process.

Preferably, the number of times of oblique evaporation performed in a direction parallel to the third channel is two, and the sum of the plating angles of the two oblique evaporation is 180 degrees.

In order to solve the technical problem, the invention further provides a superconducting quantum interferometer obtained by the preparation method according to any one of the above.

In contrast to the prior art, the method for manufacturing a superconducting quantum interferometer according to the present invention includes forming a first junction circuit including at least one first josephson junction and a second junction circuit including at least one second josephson junction on a substrate, where the first junction circuit is electrically connected to one end of the second junction circuit and the other end of the second junction circuit is electrically connected to the other end of the first junction circuit through a conductor element, so that the first junction circuit and the second junction circuit form a closed loop to form the superconducting quantum interferometer, and since the number and/or the connection relationship between the first josephson junction and the second josephson junction are configured to make the equivalent resistances of the first junction circuit and the second junction circuit different from each other, the asymmetry of the superconducting quantum interferometer may be increased, that is, and the bit frequency of non-degenerate dots may be indirectly increased. Compared with the prior art, the method can be used for preparing the non-degenerate point superconducting quantum interferometer with higher bit frequency, so that stronger quantum information processing capacity is realized.

The superconducting quantum interferometer provided by the invention is prepared by the preparation method of the superconducting quantum interferometer, so that the superconducting quantum interferometer has the same beneficial effects, and the description is omitted.

Drawings

Fig. 1 is a schematic flow chart of a method for manufacturing a superconducting quantum interferometer according to an embodiment of the present invention.

FIG. 2 is a specific flow chart of step S2 of the preparation method shown in FIG. 1.

Fig. 3 is a specific flowchart of steps S21A and S22A in fig. 2 when the direct evaporation process is employed.

Fig. 4a to 4h are schematic diagrams of the preparation of a first josephson junction and a second josephson junction using a direct evaporation process.

Fig. 5 is a specific flowchart of steps S21A and S22A in fig. 2 when the oblique evaporation process is used.

Fig. 6a to 6f are schematic diagrams of the preparation of a first and a second josephson junction using an oblique evaporation process.

FIG. 7 is a schematic diagram of the evaporation direction in the oblique evaporation process.

Fig. 8a and 8b are schematic views of line defects occurring when one oblique evaporation is performed in a direction parallel to the third channel.

Fig. 9 is a specific flowchart of step S2 in the preparation method shown in fig. 1 when a plurality of second josephson junctions 21 are connected in series.

Fig. 10 is a detailed flowchart of steps S21B and S22B in fig. 9 when the direct evaporation process is employed.

Fig. 11a to 11h are schematic diagrams of the preparation of a first josephson junction and a plurality of second josephson junctions in series, using a direct evaporation process.

Fig. 12 is a specific flowchart of steps S21B and S22B in fig. 9 when the oblique evaporation process is employed.

Fig. 13a to 13f are schematic diagrams of the preparation of a first josephson junction and a plurality of second josephson junctions in series, using a tilted evaporation process.

Fig. 14 is a specific flowchart of step S2 in the preparation method shown in fig. 1 when a plurality of second josephson junctions 21 are connected in parallel.

Fig. 15 is a detailed flowchart of steps S21C and S22C in fig. 14 when the direct evaporation process is employed.

Fig. 16a to 16h are schematic diagrams of the preparation of a first josephson junction and a plurality of parallel second josephson junctions when a direct evaporation process is used.

Fig. 17 is a detailed flowchart of step S21C and step S22C in fig. 14 when the oblique evaporation process is employed.

Fig. 18a to 18f are schematic diagrams of the preparation of a first josephson junction and a plurality of parallel second josephson junctions using a tilted evaporation process.

Detailed Description

The following describes in more detail embodiments of the present invention with reference to the schematic drawings. Advantages and features of the present invention will become apparent from the following description and claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is provided for the purpose of facilitating and clearly illustrating embodiments of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Referring to fig. 1, an embodiment of the present invention provides a method for fabricating a superconducting quantum interferometer. The preparation method comprises the following steps:

s1: a substrate is provided.

S2: and forming a first junction circuit composed of at least one first Josephson junction and a second junction circuit composed of at least one second Josephson junction on the substrate, wherein the first junction circuit is electrically connected with one end of the second junction circuit and the other end is open. The number and/or connection relationship of the first and second josephson junctions is configured such that the equivalent resistances of the first and second junction circuits are not equal.

One end of the first junction circuit and one end of the second junction circuit can be directly connected to realize electric connection or indirectly connected to realize electric connection. The other end of the first junction circuit 1 and the other end of the second junction circuit 2 are both open-circuited and not electrically connected to each other.

S3: conductor elements electrically connected to the other ends of the first junction circuit and the second junction circuit, respectively, are formed on the substrate to constitute a superconducting quantum interferometer.

The conductor element is electrically connected with the other end of the first junction circuit and the other end of the second junction circuit, and the first junction circuit and the second junction circuit are connected in parallel through the conductor element to form a closed loop, so that the superconducting quantum interferometer is formed. The conductor element may be a pad, a via, or other electrical connection structure, and the electrical connection structure may be multiple, for example, the conductor element may be two pads.

The inventor of the application finds out in long-term research that the bit frequency of a non-degenerate point of a qubit is related to the asymmetry d of two josephson junctions in a superconducting quantum interferometer, wherein the range of the asymmetry d is that d is more than or equal to 0 and less than 1, and the higher the asymmetry d is, the higher the bit frequency of the non-degenerate point is, the longer the decoherence time possessed by the non-degenerate point is.

Asymmetry d = (E) of superconducting quantum interferometer _j1 -E _j2 )/(E _j1 +E _j2 ). Wherein E is _j ＝I _c Φ ₀ Per 2 π is the energy of the Josephson junction, E _j1 、E _j2 Then represent the energy of the two Josephson junctions, phi ₀ H is Planck constant, e is elementary charge, I _c Is the critical current of the josephson junction and represents the maximum superconducting current that the josephson junction can accommodate.

Wherein the content of the first and second substances,

in the above formula, delta is a superconducting energy gap, R _normal Is the normal resistance of the josephson junction. For a typical Josephson junction with a hierarchical structure of Al-AlOx-Al, the critical current of the Josephson junction can be calculated using empirical formula at a temperature well below the superconducting transition temperature of aluminum, 1.18K

And estimating, wherein R is the resistance value of the Josephson junction at normal temperature.

It can be seen from the asymmetry calculation formula that the asymmetry of the superconducting quantum interferometer depends on the resistance difference of the two josephson junctions. According to the superconducting quantum interferometer prepared by the preparation method, the number and/or the connection relation of the first Josephson junctions and the second Josephson junctions are configured to change the equivalent resistance of the first junction circuit and the second junction circuit, so that the first junction circuit and the second junction circuit are not equal to each other, and further the asymmetry of the superconducting quantum interferometer can be improved.

In this embodiment, the resistances of the first and second josephson junctions are not equal. In particular, since the resistance of the josephson junctions is related to the area and the thickness of the barrier layer, the unequal resistance of the first and second josephson junctions may be embodied as unequal area and/or thickness of the barrier layer of the first and second josephson junctions. In order to facilitate the process preparation of the first junction circuit and the second junction circuit, the present application prefers that the barrier layers of the first josephson junction and the second josephson junction have equal thickness but unequal areas.

In some embodiments of the present application, the number of first josephson junctions and second josephson junctions is one. Such a circuit structure is the simplest, and the connection relationship between the first josephson junction and the second josephson junction does not need to be considered. Please refer to fig. 2, which is a specific flowchart of step S2 in the manufacturing method shown in fig. 1. A step of forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on a substrate, that is, step S2 includes:

S21A: a first superconducting wire and a second superconducting wire connected to each other are formed on a substrate.

S22A: a barrier layer is formed on surfaces of the first and second superconducting lines, and a third superconducting line overlapping the first superconducting line and a fourth superconducting line overlapping the second superconducting line are formed on the substrate to form a first Josephson junction at the overlapping of the first superconducting line and a second Josephson junction having a different area from the first Josephson junction at the overlapping of the second superconducting line.

The first superconducting wire, the third superconducting wire and the first Josephson junction form a first junction circuit, and the second superconducting wire, the fourth superconducting wire and the second Josephson junction form a second junction circuit. After the first junction circuit and the second junction circuit are obtained, one end of the first superconducting wire and one end of the second superconducting wire, which are connected to each other, are used as one end of the first junction circuit and one end of the second junction circuit, which are connected to each other, respectively, and one end of the third superconducting wire and one end of the fourth superconducting wire are used as the other end of the first junction circuit and the other end of the second junction circuit, respectively.

Since the number of the first josephson junction and the second josephson junction is one, the equivalent resistance of the first junction circuit is equal to the resistance of the first josephson junction, the equivalent resistance of the second junction circuit is equal to the resistance of the first josephson junction, and since the thicknesses of the barrier layers of the first josephson junction and the second josephson junction are equal but the areas of the barrier layers are not equal, the resistance of the first josephson junction is not equal to the resistance of the second josephson junction, and further the equivalent resistance of the first junction circuit is not equal to the equivalent resistance of the second junction circuit. In order to realize that the areas of the first josephson junction and the second josephson junction are not equal, the line widths of the first superconducting line, the second superconducting line, the third superconducting line and the fourth superconducting line only need to be controlled. Further, in order to facilitate control of the areas of the first and second josephson junctions, the first superconducting line vertically overlaps the third superconducting line, and the second superconducting line vertically overlaps the fourth superconducting line.

The first, second, third and fourth superconducting wires may be prepared by a direct evaporation or oblique evaporation process.

When prepared by the direct evaporation process, referring to fig. 3, the step of forming the first superconducting wire and the second superconducting wire connected to each other on the substrate, i.e., step S21A, includes:

S211A: a first photoresist layer is formed on a substrate.

As shown in fig. 4a, a schematic diagram is shown after a first photoresist layer is formed on a substrate. A first photoresist layer 210 is formed on the substrate 100.

S212A: and exposing a first channel and a second channel which are communicated with each other on the first photoresist layer.

As shown in fig. 4b, the first trench and the second trench are exposed on the first photoresist layer. The first trench 201 and the second trench 202, which are communicated with each other, are exposed on the first photoresist layer 210 through an exposure and development process.

S213A: and vertically evaporating the first channel and the second channel to form a first superconducting wire and a second superconducting wire in the first channel and the second channel respectively.

As shown in fig. 4c, the first superconducting wire and the second superconducting wire are formed. The first superconducting wire 101 is formed in the first channel 201 and the second superconducting wire 102 is formed in the second channel 202 by vertical evaporation through a direct evaporation process, and the first superconducting wire 101 and the second superconducting wire 102 are connected because the first channel 201 and the second channel 202 are communicated with each other.

Further, the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a fourth superconducting wire overlapping the second superconducting wire on the substrate, that is, step S22A includes:

S221A: and stripping the first photoresist layer to form a second photoresist layer on the substrate.

As shown in fig. 4d, after a second photoresist layer is formed on the substrate. After the first photoresist layer 210 is stripped, a second photoresist layer 220 is formed on the substrate 100.

S222A: a third channel intersecting the first superconducting wire and a fourth channel intersecting the second superconducting wire are exposed on the second photoresist layer.

As shown in fig. 4e, the third trench and the fourth trench are exposed on the second photoresist layer. A third channel 203 and a fourth channel 204 are exposed on the second photoresist layer 220 by an exposure and development process, the third channel 203 intersects the first superconducting wire 101, thereby exposing the first superconducting wire 101, and the fourth channel 204 intersects the second superconducting wire 102, thereby exposing the second superconducting wire 102.

S223A: a barrier layer is formed on the surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel.

As shown in fig. 4f, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 in third channel 203 and the surface of second superconducting wire 102 in fourth channel 204 by oxidation or the like.

S224A: and vertically evaporating the third channel and the fourth channel to form a third superconducting wire and a fourth superconducting wire in the third channel and the fourth channel respectively.

As shown in fig. 4g and 4h, fig. 4g is a schematic view after the third superconducting wire and the fourth superconducting wire are formed, and fig. 4h is a schematic view after the second photoresist layer is removed. The third superconducting line 103 is formed in the third channel 203 and the fourth superconducting line 104 is formed in the fourth channel 204 by vertical evaporation through a direct evaporation process, and since the third channel 203 intersects with the first superconducting line 101 and the fourth channel 204 intersects with the second superconducting line 102, the first superconducting line 101 and the third superconducting line 103 are overlapped, the second superconducting line 102 and the fourth superconducting line 104 are overlapped, and barrier layers 110 are sandwiched between the first superconducting line 203 and the fourth superconducting line 102, the first josephson junction 11 and the second josephson junction 21 are formed at the overlapped parts, the first superconducting line 101, the third superconducting line 103 and the first josephson junction 11 form a first junction circuit 1, and the second superconducting line 102, the fourth superconducting line 104 and the second josephson junction 21 form a second junction circuit 2.

When prepared by the oblique evaporation process, referring to fig. 5, the step of forming the first superconducting wire and the second superconducting wire connected to each other on the substrate, i.e., step S21A, includes:

S211B: a photoresist layer is formed on the substrate.

As shown in fig. 6a, after a photoresist layer is formed on a substrate. A photoresist layer 230 is formed on the substrate 100.

S212B: and exposing a first channel and a second channel which are parallel and mutually communicated on the photoresist layer, and a third channel which is vertically crossed with the first channel and a fourth channel which is vertically crossed with the second channel.

As shown in fig. 6b, a schematic diagram of forming a first channel, a second channel, a third channel and a fourth channel on a photoresist layer. The first, second, third and

fourth channels

201, 202, 203 and 204 are exposed on the photoresist layer 230 through an exposure and development process. The first channel 201 and the second channel 202 are parallel and communicate with each other. The first channel 201 perpendicularly intersects the third channel 203, and the second channel 202 perpendicularly intersects the fourth channel 204.

S213B: the oblique evaporation is performed in a direction parallel to the first channel so that the first superconducting wire and the second superconducting wire are formed only in the first channel and the second channel, respectively.

As shown in fig. 6c, the first superconducting wire and the second superconducting wire are formed. First superconducting wire 101 and second superconducting wire 102 are formed by plating only in first channel 201 and second channel 202 by oblique evaporation in a direction parallel to first channel 201. As shown in fig. 7, solid lines with arrows indicate the evaporation direction, dotted lines indicate horizontal projection of the evaporation direction, and the metal vapor is blocked from entering the fourth channel 204 by selecting an appropriate evaporation angle θ according to the thickness of the photoresist layer 230 and performing oblique evaporation in a direction parallel to the second channel 202, so that the second superconducting wire 102 is formed only in the second channel 202 by exposing the second channel 202 to the metal vapor regardless of the change of the evaporation angle θ.

Further, the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a fourth superconducting wire overlapping the second superconducting wire on the substrate, that is, the step S22A includes:

S221B: a barrier layer is formed on the surfaces of the first superconducting wire and the second superconducting wire.

As shown in fig. 6d, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 and the surface of second superconducting wire 102 by oxidation or the like.

S222B: and performing oblique evaporation along a direction parallel to the third channel so that a third superconducting wire and a fourth superconducting wire are formed only in the third channel and the fourth channel, respectively.

As shown in fig. 6e and 6f, fig. 6e is a schematic view after the third superconducting wire and the fourth superconducting wire are formed, and fig. 6f is a schematic view after the photoresist layer is removed. Third superconducting wire 103 and fourth superconducting wire 104 are formed by plating only in third channel 203 and fourth channel 204 by oblique evaporation in a direction parallel to third channel 203. Since the third channel 203 intersects the first superconducting line 101 and the fourth channel 204 intersects the second superconducting line 102, the first superconducting line 101 and the third superconducting line 103 overlap, the second superconducting line 102 and the fourth superconducting line 104 overlap, and the barrier layer 110 is sandwiched therebetween, a first josephson junction 11 is formed at the overlapping portion of the first superconducting line 101, a second josephson junction 21 is formed at the overlapping portion of the second superconducting line 102, the first superconducting line 101, the third superconducting line 103 and the first josephson junction 11 constitute a first junction circuit 1, and the second superconducting line 102, the fourth superconducting lines 104 and the second josephson junctions 21 constitute a second junction circuit 2.

In this embodiment, the number of times of oblique evaporation performed in a direction parallel to the third channel is two, and the sum of the plating angles of the two oblique evaporation is 180 degrees. Since first superconducting wire 101 and second superconducting wire 102 are vertically overlapped and third superconducting wire 103 and fourth superconducting wire 104 are vertically overlapped, when oblique evaporation is performed, a climbing effect may be generated at the overlapped part along the evaporation direction, that is, a line defect may occur on the opposite side of the evaporation direction, which affects the stability of electrical connection, as shown in fig. 8a and 8b, a line defect occurs in an oval frame with a dotted line in the figure, that is, fourth superconducting wire 104 is disconnected at the side wall of second superconducting wire 102 far away from the evaporation direction. And carry out twice slope coating by vaporization along being on a parallel with fourth channel direction, two coating by vaporization directions are mutually opposite to can avoid appearing the line defect.

In some embodiments of the present application, the number of first josephson junctions 11 is one, and the number of second josephson junctions 21 is plural. Such a circuit configuration needs to consider the connection relationship of the plurality of second josephson junctions 21. The plurality of second josephson junctions 21 may be connected in series or in parallel.

Fig. 9 is a specific flowchart of step S2 of the method shown in fig. 1 when a plurality of second josephson junctions 21 are connected in series. When the plurality of second josephson junctions 21 are connected in series, a step of forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on the substrate, that is, step S2 includes:

S21B: a first superconducting wire and a plurality of second superconducting wires are formed on a substrate, wherein the outermost first second superconducting wire is connected to the first superconducting wire.

S22B: barrier layers are formed on the surfaces of the first superconducting lines and the second superconducting lines, and third superconducting lines and fourth superconducting lines are formed on the substrate, wherein the third superconducting lines are overlapped with the first superconducting lines, the fourth superconducting lines are respectively overlapped with the second superconducting lines in a one-to-one correspondence mode, and each second superconducting line is further overlapped with the fourth superconducting line overlapped with the previous second superconducting line, so that a first Josephson junction is formed at the overlapped part of the first superconducting lines, and a second Josephson junction is formed at the overlapped part of the second superconducting lines.

The first superconducting line, the third superconducting line and the first Josephson junction form a first junction circuit, and the second superconducting lines, the fourth superconducting lines and the second Josephson junctions form a second junction circuit. After the first junction circuit and the second junction circuit are obtained, the end of the first superconducting wire and the end of the first outermost second superconducting wire, which are connected to each other, are used as the end of the first junction circuit and the end of the second junction circuit, which are connected to each other, the end of the third superconducting wire is used as the other end of the first junction circuit, and the end of the fourth superconducting wire, which is overlapped with only the last outermost second superconducting wire, is used as the other end of the second junction circuit.

Since there is only one first josephson junction, the equivalent resistance of the first junction circuit is equal to the resistance of the first josephson junction, and the plurality of second josephson junctions are connected in series, then the equivalent resistance of the second junction circuit is equal to the total resistance of the plurality of second josephson junctions after the series connection. In order to increase the asymmetry of the superconducting quantum interferometer as much as possible, the area of the first josephson junction is typically larger than the area of the second josephson junction.

When prepared by the direct evaporation process, referring to fig. 10, the step of forming a first superconducting wire and a plurality of second superconducting wires on a substrate, i.e., step S21B, includes:

S211C: a first photoresist layer is formed on a substrate.

As shown in fig. 11a, a first photoresist layer is formed on a substrate. A first photoresist layer 210 is formed on the substrate 100.

S212C: and exposing a first channel and a plurality of second channels on the first photoresist layer, wherein the first second channel on the outermost side is communicated with the first channel.

As shown in fig. 11b, the first trench and the plurality of second trenches are formed on the first photoresist layer. The first trench 201 and the plurality of second trenches 202 are exposed on the first photoresist layer 210 through an exposure and development process. The outermost first one of the second channels 202 communicates with the first channel 201. In the present embodiment, the first channel 201 and the plurality of second channels 202 are parallel to each other.

S213C: and vertically evaporating the first channel and the plurality of second channels to form a first superconducting wire and a second superconducting wire in the first channel and each second channel respectively.

As shown in fig. 11c, the first superconducting wire and the plurality of second superconducting wires are formed. The first superconducting wire 101 is formed in the first channel 201 and the second superconducting wire 102 is formed in the second channel 202 by vertical evaporation through a direct evaporation process, and the first superconducting wire 101 is connected to the second superconducting wire 102 in the first channel 202 because the first channel 201 and the first channel 202 are communicated with each other.

Further, the step of forming a barrier layer on the surfaces of the first superconducting wire and the plurality of second superconducting wires and forming a third superconducting wire and a plurality of fourth superconducting wires on the substrate, that is, the step S22B includes:

S221C: and stripping the first photoresist layer to form a second photoresist layer on the substrate.

As shown in fig. 11d, a second photoresist layer is formed on the substrate. After the first photoresist layer 210 is stripped, a second photoresist layer 220 is formed on the substrate 100, and the second photoresist layer 220 covers the substrate 100, the first superconducting wire 101 and the second superconducting wire 102.

S222C: and exposing a third channel intersected with the first superconducting wire and a plurality of fourth channels respectively intersected with the plurality of second superconducting wires in a one-to-one correspondence manner on the second photoresist layer, wherein the fourth channel intersected with each second superconducting wire is also intersected with the next second superconducting wire.

Fig. 11e is a schematic diagram of the third trench and the fourth trenches exposed on the second photoresist layer. A third channel 203 and a plurality of fourth channels 204 are exposed on the second photoresist layer 220 by an exposure and development process, and the third channel 203 intersects the first superconducting wire 101, thereby exposing the first superconducting wire 101. The plurality of fourth channels 204 respectively intersect the plurality of second superconducting wires 102 in a one-to-one correspondence, and meanwhile, the fourth channel 204 intersecting each second superconducting wire 102 also intersects the subsequent second superconducting wire 102, so that the last second superconducting wire at the outermost side intersects only one fourth channel 204, and the other second superconducting wires intersect two fourth channels 204, so that the fourth channels 204 expose the second superconducting wires 102.

S223C: a barrier layer is formed on the surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel.

As shown in fig. 11f, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 in third channel 203 and the surface of second superconducting wire 102 in fourth channel 204 by oxidation or the like.

S224C: and vertically evaporating the third channel and the fourth channel to form a third superconducting wire and a fourth superconducting wire in the third channel and each fourth channel respectively.

As shown in fig. 11g and 11h, fig. 11g is a schematic view after the third superconducting wire and the plurality of fourth superconducting wires are formed, and fig. 11h is a schematic view after the second photoresist layer is removed. Third superconducting wires 103 are formed in the third channels 203 and fourth superconducting wires 104 are formed in each fourth channel 204 by vertical evaporation through a direct evaporation process, so that the first superconducting wires 101 overlap the third superconducting wires 103, the plurality of second superconducting wires 102 overlap the plurality of fourth superconducting wires 104, respectively, and each second superconducting wire 102 also overlaps the fourth superconducting wire 104 overlapping the previous second superconducting wire 102. Then, the first josephson junctions 11 are formed at the intersections of the first superconducting lines 101, the second josephson junctions 21 are formed at the intersections of each of the second superconducting lines, the first superconducting lines 101, the third superconducting lines 103 and the first josephson junctions 11 constitute first junction circuits 1, and the second superconducting lines 102, the fourth superconducting lines 104 and the second josephson junctions 21 constitute second junction circuits 2.

When prepared by the oblique evaporation process, referring to fig. 12, the step of forming a first superconducting wire and a plurality of second superconducting wires on a substrate, i.e., step S21B, includes:

S211D: a photoresist layer is formed on the substrate.

As shown in fig. 13a, a photoresist layer is formed on a substrate. A photoresist layer 230 is formed on the substrate 100.

S212D: and exposing a first channel and a plurality of second channels on the photoresist layer, as well as a third channel vertically crossed with the first channel and a plurality of fourth channels vertically crossed with the plurality of second channels respectively in a one-to-one correspondence manner, wherein the first channel and the plurality of second channels are parallel, the first second channel at the outermost side is communicated with the first channel, and each second channel is also vertically crossed with the fourth channel crossed with the previous second channel.

As shown in fig. 13b, the first trench, the plurality of second trenches, the third trench and the plurality of fourth trenches are formed on the photoresist layer. The first channel 201, the plurality of second channels 202, the third channel 203 and the plurality of fourth channels 204 are exposed on the photoresist layer 230 through an exposure and development process. The first channel 201 and the outermost first and second channels 202 are parallel and communicate with each other. The first channel 201 is vertically crossed with the third channel 203, the plurality of fourth channels 204 are vertically crossed with the plurality of second channels 202 in a one-to-one correspondence manner, and meanwhile, each second channel 202 is also vertically crossed with the fourth channel 204 crossed with the previous second channel 202.

S213D: the oblique evaporation is performed in a direction parallel to the first channel so that the first superconducting wire and the second superconducting wire are formed only in the first channel and each of the second channels, respectively.

As shown in fig. 13c, the first superconducting wire and the plurality of second superconducting wires are formed. First superconducting wire 101 and second superconducting wire 102 are formed by plating only in first channel 201 and second channel 202 by oblique evaporation in a direction parallel to first channel 201.

S221D: a barrier layer is formed on the surface of the first superconducting wire and the surface of each second superconducting wire.

As shown in fig. 13d, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 and the surface of second superconducting wire 102 by oxidation or the like.

S222D: and performing oblique evaporation along the direction parallel to the third channel so as to form a third superconducting wire and a fourth superconducting wire in the third channel and each fourth channel respectively.

As shown in fig. 13e and 13f, fig. 13e is a schematic view after the third superconducting wire and the plurality of fourth superconducting wires are formed, and fig. 13f is a schematic view after the second photoresist layer is removed. Third superconducting wire 103 and fourth superconducting wire 104 are formed by plating only in third channel 203 and fourth channel 204 by oblique evaporation in a direction parallel to third channel 203. Since the third channel 203 intersects the first superconducting line 101 and the fourth channel 204 intersects the second superconducting line 102, the first superconducting line 101 and the third superconducting line 103 overlap each other, the second superconducting line 102 and the fourth superconducting line 104 overlap each other with the barrier layer 110 interposed therebetween, a first josephson junction 11 is formed at the overlapping portion of the first superconducting line 101, a second josephson junction 21 is formed at the overlapping portion of each second superconducting line 102, the first superconducting line 101, the third superconducting line 103 and the first josephson junction 11 constitute a first junction circuit 1, and the second superconducting lines 102, the fourth superconducting lines 104 and the second josephson junctions 21 constitute a second junction circuit 2.

In this embodiment, the number of times of oblique evaporation performed in a direction parallel to the third channel is two, and the sum of the coating angles of the two oblique evaporation is 180 degrees, so that the occurrence of line defects can be avoided by performing the two oblique evaporation.

Fig. 14 is a specific flowchart of step S2 of the method of fig. 1 when a plurality of second josephson junctions 21 are connected in parallel. When the connection relationships of the plurality of second josephson junctions 21 are in parallel, a step of forming a first junction circuit composed of at least one first josephson junction and a second junction circuit composed of at least one second josephson junction on the substrate, that is, step S2 includes:

S21C: a first superconducting wire and a second superconducting wire connected to each other are formed on a substrate.

S22C: a barrier layer is formed on surfaces of the first and second superconducting lines, and a third superconducting line overlapping the first superconducting line and a plurality of fourth superconducting lines overlapping the second superconducting line are formed on the substrate to form a first Josephson junction at the overlapping of the first superconducting line and a second Josephson junction at the overlapping of the second superconducting line.

The first superconducting line, the third superconducting line and the first Josephson junction form a first junction circuit, and the second superconducting line, the fourth superconducting lines and the second Josephson junctions form a second junction circuit. After the first junction circuit and the second junction circuit are obtained, the end where the first superconducting wire and the second superconducting wire are connected with each other is used as the end where the first junction circuit and the second junction circuit are connected with each other, the end of the third superconducting wire is used as the other end of the first junction circuit, and the end of each fourth superconducting wire in the same direction is used as the other end of the second junction circuit.

Since there is only one first josephson junction, the equivalent resistance of the first junction circuit is equal to the resistance of the first josephson junction, and the plurality of second josephson junctions are connected in parallel, then the equivalent resistance of the second junction circuit is equal to the total resistance of the plurality of second josephson junctions after being connected in parallel. In order to increase the asymmetry of the superconducting quantum interferometer as much as possible, the area of the first josephson junction is typically smaller than the area of the second josephson junction.

When prepared by the direct evaporation process, referring to fig. 15, the step of forming the first superconducting wire and the second superconducting wire connected to each other on the substrate, i.e., step S21C, includes:

S211E: a first photoresist layer is formed on a substrate.

As shown in fig. 16a, a first photoresist layer is formed on a substrate. A first photoresist layer 210 is formed on the substrate 100.

S212E: and exposing a first channel and a second channel which are communicated with each other on the first photoresist layer.

As shown in fig. 16b, the first trench and the second trench are exposed on the first photoresist layer. The first trench 201 and the second trench 202, which are communicated with each other, are exposed on the first photoresist layer 210 through an exposure and development process.

S213E: and vertically evaporating the first channel and the second channel to form a first superconducting wire and a second superconducting wire in the first channel and the second channel respectively.

As shown in fig. 16c, the first superconducting wire and the second superconducting wire are formed. The first superconducting wire 101 is formed in the first channel 201 and the second superconducting wire 102 is formed in the second channel 202 by vertical evaporation through a direct evaporation process, and the first superconducting wire 101 and the second superconducting wire 102 are connected because the first channel 201 and the second channel 202 are communicated with each other.

Further, the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a plurality of fourth superconducting wires overlapping the second superconducting wire on the substrate, that is, the step S22C includes:

S221E: and stripping the first photoresist layer to form a second photoresist layer on the substrate.

As shown in fig. 16d, after a second photoresist layer is formed on the substrate. After the first photoresist layer 210 is stripped, a second photoresist layer 220 is formed on the substrate 100.

S222E: and exposing a third channel intersected with the first superconducting wire and a plurality of fourth channels respectively intersected with the second superconducting wire on the second photoresist layer.

As shown in fig. 16e, the third trench and the plurality of fourth trenches are formed on the second photoresist layer. Through the exposure and development process, a third channel 203 and a plurality of fourth channels 204 are exposed on the second photoresist layer 220, the third channel 203 intersects with the first superconducting wire 101, thereby exposing the first superconducting wire 101, and the plurality of fourth channels 204 respectively intersect with the second superconducting wire 102, thereby exposing the second superconducting wire 102.

S223E: a barrier layer is formed on the surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel.

As shown in fig. 16f, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 in third channel 203 and the surface of second superconducting wire 102 in fourth channel 204 by oxidation or the like.

As shown in fig. 16g and 16h, fig. 16g is a schematic view after the third superconducting wire and the plurality of fourth superconducting wires are formed, and fig. 16h is a schematic view after the second photoresist layer is removed. The third superconducting line 103 is formed in the third channel 203 by vertical evaporation through a direct evaporation process, the fourth superconducting lines 104 are respectively formed in the fourth channels 204, the third channel 203 intersects with the first superconducting line 101, and the fourth channels 204 intersect with the second superconducting line 102, so that the first superconducting line 101 and the third superconducting line 103 are overlapped, the second superconducting line 102 and the fourth superconducting lines 104 are overlapped, and a barrier layer 110 is sandwiched between the first superconducting line 101, the third superconducting line 103 and the first josephson junction 11, the first josephson junction 11 is formed at the overlapped part, the second superconducting line 102, the fourth superconducting lines 104 and the second josephson junctions 21 form a first junction circuit 1, and the second superconducting line 102, the fourth superconducting lines 104 and the second josephson junctions 21 form a second junction circuit 2.

When prepared by the oblique evaporation process, referring to fig. 17, the step of forming a first superconducting wire and a second superconducting wire connected to each other on a substrate, i.e., step S21C, includes:

S211F: a photoresist layer is formed on the substrate.

As shown in fig. 18a, a photoresist layer is formed on a substrate. A photoresist layer 230 is formed on the substrate 100.

S212F: and exposing a first channel and a second channel on the photoresist layer, and a third channel vertically crossed with the first channel and a plurality of fourth channels respectively vertically crossed with the second channel, wherein the first channel and the second channel are parallel and communicated.

As shown in fig. 18b, the first trench, the second trench, the third trench and the plurality of fourth trenches are formed on the photoresist layer. The first channel 201, the second channel 202, the third channel 203 and the plurality of fourth channels 204 are exposed on the photoresist layer 230 through an exposure and development process. The first channel 201 and the second channel 202 are parallel and communicate with each other. The first channel 201 vertically crosses the third channel 203, and the plurality of fourth channels 204 vertically crosses the second channels 202, respectively.

S213F: the oblique evaporation is performed in a direction parallel to the first channel so that the first superconducting wire and the second superconducting wire are formed only in the first channel and the second channel, respectively.

As shown in fig. 18c, the first superconducting wire and the second superconducting wire are formed. First superconducting wire 101 and second superconducting wire 102 are formed by plating only in first channel 201 and second channel 202 by oblique evaporation in a direction parallel to first channel 201.

S221F: a barrier layer is formed on the surfaces of the first superconducting wire and the second superconducting wire.

As shown in fig. 18d, the barrier layer is formed. Barrier layer 110 is formed on the surface of first superconducting wire 101 and the surface of second superconducting wire 102 by oxidation or the like.

S222F: and performing oblique evaporation along the direction parallel to the third channel so as to form a third superconducting wire and a fourth superconducting wire in the third channel and each fourth channel respectively.

As shown in fig. 18e and 18f, fig. 18e is a schematic view after the third superconducting wire and the plurality of fourth superconducting wires are formed, and fig. 18f is a schematic view after the photoresist layer is removed. Third superconducting wire 103 and fourth superconducting wire 104 are formed by plating only in third channel 203 and fourth channel 204 by oblique evaporation in a direction parallel to third channel 203. Since the third channel 203 intersects the first superconducting line 101 and each of the fourth channels 204 intersects the second superconducting line 102, the first superconducting line 101 and the third superconducting line 103 overlap each other, the second superconducting line 102 and the fourth superconducting line 104 overlap each other with the barrier layer 110 interposed therebetween, the first josephson junction 11 and the second josephson junction 21 are formed at the first overlapping portion, the first superconducting line 101, the third superconducting line 103 and the first josephson junction 11 form the first junction circuit 1, and the second superconducting line 102, the fourth superconducting line 104 and the second josephson junction 21 form the second junction circuit 2.

The invention also provides a superconducting quantum interferometer which is prepared according to the preparation method of the superconducting quantum interferometer of the embodiment. Because the equivalent resistance of the first junction circuit is not equal to that of the second junction circuit, the asymmetry of the superconducting quantum interferometer is improved, so that the bit frequency of the nondegenerate point can be improved, the decoherence time possessed by the nondegenerate point can be correspondingly improved by applying the quantum bit of the quantum interferometer, and the stronger quantum information processing capability is realized.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example" or "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. And the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for preparing a superconducting quantum interferometer, comprising:

providing a substrate;

2. The method of claim 1, wherein the resistances of the first josephson junction and the second josephson junction are not equal.

3. A method of manufacturing according to claim 2, wherein the areas and/or barrier layer thicknesses of the first and second josephson junctions are not equal.

4. The method of claim 3, wherein the barrier layers of the first and second Josephson junctions are equal in thickness but unequal in area.

5. The method of claim 4, wherein the number of the first and second josephson junctions is one.

6. The method of claim 5, wherein the step of forming a first junction circuit consisting of at least one first Josephson junction and a second junction circuit consisting of at least one second Josephson junction on the substrate comprises:

wherein the first superconducting line, the third superconducting line and the first josephson junction constitute a first junction circuit, and the second superconducting line, the fourth superconducting line and the second josephson junction constitute a second junction circuit.

7. The method of manufacturing according to claim 6, wherein the step of forming a first superconducting wire and a second superconducting wire connected to each other on the substrate comprises:

forming a first photoresist layer on the substrate;

8. The manufacturing method according to claim 7, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a fourth superconducting wire overlapping the second superconducting wire on the substrate comprises:

9. The method of manufacturing according to claim 6, wherein the step of forming a first superconducting wire and a second superconducting wire connected to each other on the substrate comprises:

forming a photoresist layer on the substrate;

10. The manufacturing method according to claim 9, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a fourth superconducting wire overlapping the second superconducting wire on the substrate comprises:

11. The method of claim 4, wherein the number of the first Josephson junctions is one and the number of the second Josephson junctions is more than one.

12. The method of claim 11, wherein the plurality of second josephson junctions are connected in series.

13. The method of claim 12, wherein the step of forming a first junction circuit consisting of at least one first josephson junction and a second junction circuit consisting of at least one second josephson junction on the substrate comprises:

forming barrier layers on surfaces of the first and second superconducting lines, and forming a third superconducting line and a fourth superconducting line on the substrate, wherein the third superconducting line overlaps the first superconducting line, the fourth superconducting lines overlap the second superconducting lines in a one-to-one correspondence, respectively, and each second superconducting line further overlaps the fourth superconducting line overlapping the previous second superconducting line to form a first josephson junction at the overlap of the first superconducting line and a second josephson junction at the overlap of the second superconducting lines;

14. The method of manufacturing according to claim 13, wherein the step of forming a first superconducting wire and a plurality of second superconducting wires on the substrate includes:

forming a first photoresist layer on the substrate;

and vertically evaporating the first channel and the plurality of second channels, and respectively forming a first superconducting wire and a second superconducting wire in the first channel and each second channel.

15. The method of manufacturing according to claim 14, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the plurality of second superconducting wires and forming a third superconducting wire and a plurality of fourth superconducting wires on the substrate comprises:

16. The method of manufacturing according to claim 13, wherein the step of forming a first superconducting wire and a plurality of second superconducting wires on the substrate includes:

forming a photoresist layer on the substrate;

exposing a first channel and a plurality of second channels, a third channel vertically crossed with the first channel and a plurality of fourth channels vertically crossed with the second channels in a one-to-one correspondence mode respectively on the photoresist layer, wherein the first channel is parallel to the second channels, the first channel on the outermost side is communicated with the first channel, and each second channel is also vertically crossed with the fourth channel crossed with the previous second channel;

performing oblique evaporation in a direction parallel to the first channel such that a first superconducting wire and a second superconducting wire are formed only in the first channel and each of the second channels, respectively.

17. The method of manufacturing according to claim 16, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the plurality of second superconducting wires and forming a third superconducting wire and a plurality of fourth superconducting wires on the substrate comprises:

18. The method of claim 11, wherein the plurality of second josephson junctions are connected in parallel.

19. The method of claim 18, wherein the step of forming a first junction circuit consisting of at least one first josephson junction and a second junction circuit consisting of at least one second josephson junction on the substrate comprises:

forming a barrier layer on surfaces of the first and second superconducting lines, and forming a third superconducting line overlapping the first superconducting line and a plurality of fourth superconducting lines overlapping the second superconducting line on the substrate to form a first josephson junction at the overlap of the first superconducting line and a second josephson junction at the overlap of the second superconducting line;

20. The method of manufacturing according to claim 19, wherein the step of forming a first superconducting wire and a second superconducting wire connected to each other on the substrate comprises:

forming a first photoresist layer on the substrate;

21. The manufacturing method according to claim 20, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a plurality of fourth superconducting wires overlapping the second superconducting wire on the substrate comprises:

22. The method of manufacturing according to claim 19, wherein the step of forming a first superconducting wire and a second superconducting wire connected to each other on the substrate comprises:

forming a photoresist layer on the substrate;

23. The production method according to claim 22, wherein the step of forming a barrier layer on the surfaces of the first superconducting wire and the second superconducting wire, and forming a third superconducting wire overlapping the first superconducting wire and a plurality of fourth superconducting wires overlapping the second superconducting wire on the substrate comprises:

24. The method of manufacturing according to claim 8, 15, or 21, further comprising, before the step of forming a barrier layer on the surface of the first superconducting wire in the third channel and the second superconducting wire in the fourth channel:

25. The production method according to claim 17 or 23, wherein the number of times of oblique evaporation performed in a direction parallel to the third channel is two, and a sum of coating angles of the two oblique evaporation is 180 degrees.

26. A superconducting quantum interferometer obtained by the method of manufacture according to any one of claims 1 to 25.