Impedance matching device and quantum processor for superconducting quantum chip

Abstract

The invention discloses an impedance matching device and a quantum processor of a superconducting quantum chip, which relate to the technical field of quantum chips and include a chip body, a lead and a PCB board body; the chip body includes a chip main body circuit and a chip electrode, the PCB board body includes a PCB board main body circuit and a PCB board electrode, and the end of the chip electrode is connected with the end of the PCB board electrode through a lead; impedance matching circuits are arranged in the chip body and the PCB board body, the chip main body circuit and the chip electrode are connected through the impedance matching circuit, and the PCB board main body circuit and the PCB board electrode are connected through the impedance matching circuit; the impedance matching device and the quantum processor are integrated into the chip circuit of a superconducting quantum processor, and are matched with a corresponding metal sealing method to solve the problem of impedance mismatch from the chip end, thereby improving the performance of the superconducting quantum processor.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum chips, and in particular to an impedance matching device and a quantum processor of a superconducting quantum chip. Background Art

[0002] The superconducting quantum processor chip is made of superconducting film. In order to ensure the performance of quantum bits during operation, electromagnetic field shielding and metal sealing are required. To solve the problem of signal transmission, a widely used method is to connect the chip to the printed circuit board (PCB board) inside the sealed box with leads. Since the superconducting quantum processor chip operates in the microwave frequency band, it is necessary to transmit signals at the single photon energy level in an extremely low electromagnetic noise environment. However, impedance mismatch often occurs at the binding connection between the chip and the PCB package, reducing the measurement accuracy and the performance of the quantum processor.

[0003] The widely used connection method between superconducting quantum processor chip and PCB board is as follows: Figure 3 and 4 shown. Figure 3 is a side view, Figure 4 It is a top view, 01 is the line end electrode on the chip, 02 is the electrode on the PCB board, 03 is the binding lead, and the number of leads between a pair of electrodes is usually between 1 and several. The two ends of 03 are connected to the surface of the line end electrode 01 and the electrode 02 on the PCB board by the binding machine to form a path.

[0004] According to the current technical level, the impedance of the line end electrode 01 and the electrode 02 on the PCB board is easily designed and processed to be 50 ohms, while the binding lead 03 is usually a superconducting aluminum wire, and its circuit component is mainly a large inductor with only a very small parasitic capacitance. Therefore, there is a large impedance far exceeding 50 ohms in the binding lead 03 part, resulting in an impedance mismatch problem.

[0005] Impedance mismatch on superconducting quantum processors can lead to a series of problems:

[0006] 1) Energy transfer is blocked. Impedance mismatch will cause reflection of signals or energy, reducing transmission efficiency; 2) Standing wave formation. Reflected and incompletely absorbed energy will form standing waves on the transmission line, causing the signal strength to increase in some places and decrease in other places, which has a great impact on the reading on the superconducting quantum chip; 3) Power loss. Power that is not fully absorbed by the load will be consumed in the form of heat, reducing system efficiency; 4) Signal distortion. Impedance mismatch will cause changes in amplitude and phase of the bit control signal.

[0007] As the number of bits in superconducting quantum processors increases, the requirements for reading and manipulation accuracy become higher and higher. The impedance mismatch caused by the lead connection between the chip and the PCB has gradually become a constraint on improving the performance of superconducting quantum bit processors, and it is urgently needed to be solved technically. Summary of the invention

[0008] Based on the technical problems existing in the background technology, the present invention proposes an impedance matching device and a quantum processor of a superconducting quantum chip, which improves the performance of the superconducting quantum processor.

[0009] The present invention provides an impedance matching device for a superconducting quantum chip, comprising a chip body, leads and a PCB board body;

[0010] The chip body includes a chip main body circuit and a chip electrode, the PCB board body includes a PCB board main body circuit and a PCB board electrode, and the end of the chip electrode is connected to the end of the PCB board electrode through a lead wire;

[0011] Impedance matching circuits are arranged in both the chip body and the PCB board body. The chip body circuit and the chip electrode are connected through the impedance matching circuit, and the PCB board body circuit and the PCB board electrode are connected through the impedance matching circuit.

[0012] Further, in the chip body, the impedance matching circuit is a set shape sequence prepared from superconducting material;

[0013] In the PCB body, the impedance matching circuit is a set shape sequence made of metal;

[0014] The structures of the two impedance matching circuits are the same.

[0015] Furthermore, the impedance matching circuit includes a first rectangular unit and a second rectangular unit, which are connected in sequence to form an impedance circuit, and one to multiple impedance circuits are connected in sequence to form an impedance matching circuit, and the impedance matching degree is controlled by controlling the number of repetitions of the impedance circuit.

[0016] Furthermore, in the chip body, the first rectangular unit located at the outermost end of the impedance matching circuit is connected to the chip body circuit, and the second rectangular unit located at the outermost end is connected to the chip electrode.

[0017] Furthermore, in the PCB board body, the first rectangular unit located at the outermost end of the impedance matching circuit is connected to the PCB board electrode, and the second rectangular unit located at the outermost end is connected to the PCB board main body circuit.

[0018] Furthermore, the impedance matching circuit is prepared by an etching process, the non-circuit part is defined as a ground plane, and the length, width and spacing between the first rectangular unit and the second rectangular unit and the ground plane are adjustable.

[0019] A quantum processor comprises the impedance matching device of the superconducting quantum chip as described above.

[0020] The impedance matching device and quantum processor of a superconducting quantum chip provided by the present invention have the advantages that: an impedance matching circuit is introduced to realize impedance matching between a chip main circuit and a lead, and is used to realize impedance matching between a PCB board main circuit and a lead; the impedance matching circuit has the advantages of simple structure, compatibility with the superconducting quantum chip preparation process, low simulation resource consumption, accurate results, etc., and can be quickly integrated into various superconducting quantum processor chips, solving the impedance mismatch problem between the chip main circuit and the lead, and the impedance mismatch problem between the PCB board main circuit and the lead; and can be integrated into the chip circuit of the superconducting quantum processor, and with the corresponding metal sealing method, the impedance mismatch problem is solved from the chip end, thereby solving the problems of energy transfer obstruction, standing wave, power loss and signal distortion caused by impedance mismatch, thereby improving the performance of the superconducting quantum processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a structural schematic diagram of an impedance matching circuit;

[0023] Figure 3 A side view of the connection method between the existing superconducting quantum processor chip and the PCB board;

[0024] Figure 4 A top view of the connection method between the existing superconducting quantum processor chip and the PCB board.

[0025] Among them, 1-chip body, 2-PCB board body, 3-lead, 4-impedance matching circuit, 11-chip main circuit, 12-chip electrode, 21-PCB board main circuit, 22-PCB board electrode, 41-first rectangular unit, 42-second rectangular unit, 43-ground plane;

[0026] 01-line end electrode on the chip, 02-electrode on the PCB board, 03-binding lead. DETAILED DESCRIPTION

[0027] Below, the technical solution of the present invention is described in detail through specific embodiments. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation disclosed below.

[0028] like Figures 1 to 4 As shown, an impedance matching device for a superconducting quantum chip proposed by the present invention includes a chip body 1, a lead 3 and a PCB board body 2; the chip body 1 includes a chip main body circuit 11 and a chip electrode 12, the PCB board body 2 includes a PCB board main body circuit 21 and a PCB board electrode 22, and the end of the chip electrode 12 is connected to the end of the PCB board electrode 22 through the lead 3; an impedance matching circuit 4 is set in both the chip body 1 and the PCB board body 2, the chip main body circuit 11 and the chip electrode 12 are connected through the impedance matching circuit 4, and the PCB board main body circuit 21 and the PCB board electrode 22 are connected through the impedance matching circuit 4.

[0029] The chip body 1 in this embodiment refers to the circuit end electrode 01 and the chip circuit where it is located. Correspondingly, the PCB board body 2 refers to the electrode 02 on the PCB board and the metal packaging structure where the PCB is located. In addition, the lead 3 in this embodiment is Figure 3 and 4 The binding lead 03 can adopt the same structure and material, and the binding connection between the lead 3 and the chip electrode 12 and the PCB board electrode 22 can also be achieved through a binding motor. The main key point of this embodiment is to set independent impedance matching circuits in the chip body 1 and the PCB board body 2, so as to solve the impedance mismatch problem at the chip end.

[0030] There is an impedance mismatch problem between the chip body and the lead, and between the PCB board body and the lead. This embodiment introduces an impedance matching circuit 4 for realizing impedance matching between the chip body circuit and the lead, and for realizing impedance matching between the PCB board body circuit and the lead. The impedance matching circuit 4 has the advantages of simple structure, compatibility with the superconducting quantum chip preparation process, low simulation resource consumption, accurate results, etc., and can be quickly integrated into various superconducting quantum processor chips, solving the impedance mismatch problem between the chip body circuit and the lead, and the impedance mismatch problem between the PCB board body circuit and the lead.

[0031] In addition, the line width of the impedance matching line 4 is 2um~20um, which can be achieved by mainstream photolithography equipment. It is made by etching process and can be processed simultaneously with the chip main line 11. The number of repetitions of the structure in the impedance matching line 4 is used to control the connectivity and attenuation dB of the line, and improve the 50 ohm matching degree of 1G~8GHz signals.

[0032] In this embodiment, in the chip body 1, the impedance matching circuit 4 is a set shape sequence made of superconducting material; in the PCB board body 2, the impedance matching circuit 4 is a set shape sequence made of metal.

[0033] The structures of the two impedance matching circuits 4 are consistent, such as Figure 2As shown, the impedance matching line 4 includes a first rectangular unit 41 and a second rectangular unit 42, the first rectangular unit 41 and the second rectangular unit 42 are connected in sequence to form an impedance line, one or more impedance lines are connected in sequence to form an impedance matching line 4, and the impedance matching degree is controlled by controlling the number of repetitions of the impedance line, wherein the impedance matching line 4 is arranged in a ground plane 43.

[0034] However, the connection modes of the impedance matching circuit 4 in the chip body 1 and the PCB board body 2 are slightly different, that is, in the chip body 1, the first rectangular unit 41 at the outermost end of the impedance matching circuit 4 is connected to the chip body circuit 11, and the second rectangular unit 42 at the outermost end is connected to the chip electrode 12. In the PCB board body 2, the first rectangular unit 41 at the outermost end of the impedance matching circuit 4 is connected to the PCB board electrode 22, and the second rectangular unit 42 at the outermost end is connected to the PCB board body circuit 21.

[0035] In addition, the impedance matching circuit 4 is prepared by etching process, and the non-circuit part is defined as the ground plane. Its structure is repeatedly composed of the first rectangular unit 41 and the second rectangular unit 42. The line width of the first rectangular unit 41 and the second rectangular unit 42 are W1 and W2, respectively, the length is L1 and L2, respectively, and the distance from the ground plane is G1 and G2. By adjusting W1, W2, L1, L2, G1, G2 of two independent impedance matching circuits 4 respectively, impedance matching can be performed with the middle lead 3.

[0036] For applications in the range of 1 GHz to 8 GHz, the first rectangular unit 41 meets an impedance of 20-50 ohms, and the second rectangular unit 42 meets an impedance of 80-120 ohms. The impedance matching degree is controlled by changing the number of repetitions of the first rectangular unit 41 and the second rectangular unit 42.

[0037] Through the above impedance matching design, this embodiment can be integrated into the superconducting quantum processor chip circuit, and with the corresponding metal sealing method, the impedance mismatch problem can be solved from the chip end, thereby solving the problems of energy transfer obstruction, standing waves, power loss and signal distortion caused by impedance mismatch, thereby improving the performance of the superconducting quantum processor.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An impedance matching device for a superconducting quantum chip, characterized in that: It comprises a chip body (1), leads (3) and a PCB board body (2); The chip body (1) comprises a chip main body circuit (11) and a chip electrode (12); the PCB board body (2) comprises a PCB board main body circuit (21) and a PCB board electrode (22); the end of the chip electrode (12) is connected to the end of the PCB board electrode (22) via a lead wire (3); An impedance matching circuit (4) is provided in both the chip body (1) and the PCB board body (2); the chip body circuit (11) and the chip electrode (12) are connected via the impedance matching circuit (4); and the PCB board body circuit (21) and the PCB board electrode (22) are connected via the impedance matching circuit (4); The impedance matching circuit (4) comprises a first rectangular unit (41) and a second rectangular unit (42); the first rectangular unit (41) and the second rectangular unit (42) are connected in sequence to form an impedance circuit; at least two impedance circuits are connected in sequence to form an impedance matching circuit (4); and the impedance matching degree is controlled by controlling the number of repetitions of the impedance circuit.

2. The impedance matching device of the superconducting quantum chip according to claim 1, characterized in that: In the chip body (1), the impedance matching line (4) is a set shape sequence made of superconducting material; In the PCB board body (2), the impedance matching circuit (4) is made of metal into a set shape sequence; The two impedance matching circuits (4) have the same structure.

3. The impedance matching device of the superconducting quantum chip according to claim 1, characterized in that: In the chip body (1), a first rectangular unit (41) located at the outermost end of the impedance matching circuit (4) is connected to the chip body circuit (11), and a second rectangular unit (42) located at the outermost end is connected to the chip electrode (12).

4. The impedance matching device of the superconducting quantum chip according to claim 1, characterized in that: In the PCB board body (2), the first rectangular unit (41) located at the outermost end of the impedance matching circuit (4) is connected to the PCB board electrode (22), and the second rectangular unit (42) located at the outermost end is connected to the PCB board main body circuit (21).

5. The impedance matching device of the superconducting quantum chip according to claim 1, characterized in that: The impedance matching circuit (4) is prepared by an etching process, the non-circuit portion is defined as a ground plane, and the length, width and spacing between the first rectangular unit (41) and the second rectangular unit (42) and the ground plane are adjustable.

6. A quantum processor, characterized in that: An impedance matching device comprising the superconducting quantum chip according to any one of claims 1 to 5.

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