Superconducting quantum chip capable of realizing uniform parameter reading, packaging module and processor

Abstract

The invention relates to the field of quantum chips, in particular to a superconducting quantum chip capable of realizing uniform parameter reading, a packaging module and a processor. The superconducting quantum chip comprises a Bosell filter, a reading cavity, at least one quantum bit, an output signal polar plate, an input signal polar plate, a first signal transmission line and a second signal transmission line. The first signal transmission line and the second signal transmission line are consistent in length and avoid odd times of a quarter wavelength corresponding to the working frequency of the Bosell filter. According to the method, a creative design rule that the length of a transmission line avoids a specific multiple of lambda / 4 is introduced, so that the standing wave resonance effect causing random drift of the reading performance of the superconducting quantum chip is eliminated fundamentally, and the certainty and predictability of the chip performance are realized; and an essential physical foundation is laid for realizing large-scale multi-bit parameter reading uniformity, so that the research and development mode of the chip is thoroughly changed, and the research and development efficiency and the success rate are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of quantum chips, specifically to a superconducting quantum chip, packaging module, and processor that achieves uniform readout parameters. Background Technology

[0002] Superconducting quantum processors typically consist of a superconducting quantum chip, a sample substrate, and a printed circuit board. The signal ports of the quantum chip are connected to corresponding ports on the printed circuit board via leads to transmit external signals. However, due to the high characteristic impedance of the leads, impedance mismatch can easily occur at the connection points, affecting the quality of the control signal and the coupling strength between the quantum device and the environment.

[0003] In common superconducting qubit readout schemes, the readout cavity and a broadband Bosell filter are coupled via capacitance or mutual inductance. The readout port of the Bosell filter is connected to a bonding plate at the chip edge via a coplanar waveguide transmission line, and then wire-bonded to the corresponding port on the printed circuit board. The impedance matching state at the readout port directly affects the effective bandwidth of the filter, and thus determines the effective linewidth of the readout cavity. Due to the high impedance of the wires, standing wave modes are easily formed between the output port of the Bosell filter and the wires, causing a significant deviation between the actual linewidth of the Bosell filter and the readout cavity and the design value.

[0004] In multi-qubit superconducting quantum chips, non-uniformity of readout parameters reduces the readout quality of qubits and limits the improvement of overall chip performance.

[0005] Therefore, existing technologies need to be improved. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention proposes a superconducting quantum chip, packaging module, and processor that achieves uniform readout parameters, aiming to solve the technical problem of non-uniform readout parameters.

[0007] In a first aspect, the present invention provides a superconducting quantum chip for achieving uniform readout parameters, comprising: A Bosell filter, wherein the Bosell filter is a half-wavelength resonant cavity structure with both ends grounded; The reading cavity is coupled to the Bosell filter via mutual inductance; At least one quantum bit is coupled to the readout cavity; The filter includes an output signal plate and an input signal plate; the output signal plate is connected to the Bosell filter via a first signal transmission line; the input signal plate is connected to the Bosell filter via a second signal transmission line. Wherein, the length of the first signal transmission line is consistent and avoids odd multiples of a quarter wavelength corresponding to the operating frequency of the Bosell filter; and / or the length of the second signal transmission line is consistent and avoids odd multiples of a quarter wavelength corresponding to the operating frequency of the Bosell filter.

[0008] Preferably, when the connection between the first signal transmission line and the Bossel filter is located near the short-circuit end of the Bossel filter, the length of the first signal transmission line avoids an odd multiple of a quarter wavelength corresponding to the operating frequency of the Bossel filter; And / or when the connection between the second signal transmission line and the Bossel filter is located near the short-circuit end of the Bossel filter, the length of the second signal transmission line avoids odd multiples of a quarter wavelength corresponding to the operating frequency of the Bossel filter.

[0009] Preferably, the Bosell filter has a characteristic bandwidth of 300MHz and a center frequency of 5-7GHz. Its bandwidth is determined by the coupling position between the output port signal transmission line and the filter.

[0010] Preferably, both the first signal transmission line and the second signal transmission line are coplanar waveguide structures with a characteristic impedance of 50Ω and a linewidth of 4-20μm.

[0011] Preferably, the mutual inductive coupling strength between the reading cavity and the Bossel filter is 5-10 pH.

[0012] Secondly, the present invention also provides a packaging module, comprising: A superconducting quantum chip for achieving uniform readout parameters through multiple channels; the superconducting quantum chip for achieving uniform readout parameters includes an output signal plate and an input signal plate; Printed circuit board electrode plate; Multiple parallel leads connect the printed circuit board electrode plate to the output signal electrode plate or the input signal electrode plate; The length and number of parallel connections of the leads connecting each output signal plate or input signal plate to the printed circuit board plate remain consistent.

[0013] Preferably, the lead wire is made of superconducting material, has a length of 1-3 mm, and a diameter of 25 μm.

[0014] Preferably, the lead wire is made of pure aluminum.

[0015] Preferably, the length of the output signal plate or the input signal plate is 0.2-0.4 mm and the width is 0.1-0.3 mm; the length of the printed circuit board plate is 0.6-1.5 mm and the width is 0.2-0.4 mm.

[0016] Thirdly, the present invention also provides a superconducting quantum processor, comprising: a packaging module; The control and reading circuit is connected to the electrode plate of the printed circuit board.

[0017] Compared with the prior art, the present invention has the following advantages: This invention provides a superconducting quantum chip, packaging module, and processor that achieves uniform readout parameters. The superconducting quantum chip of this invention achieves uniform readout parameters by introducing a creative design rule of "avoiding transmission line lengths that are multiples of λ / 4," correcting the linewidth fluctuations in the readout cavity caused by standing wave modes, thus achieving uniform readout parameters and improving the readout fidelity of qubits. It fundamentally eliminates the standing wave resonance effect that causes random drift in the readout performance of superconducting quantum chips, achieving determinism and predictability in chip performance. Furthermore, it lays an essential physical foundation for achieving uniform readout parameters across large-scale multi-qubit systems, thereby completely transforming the development model of such chips and significantly improving development efficiency and success rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a superconducting quantum chip structure for implementing uniform readout parameters in one embodiment.

[0019] Figure 2 This is a schematic diagram showing the connection between the output signal plate, the first signal transmission line, and the Bosell filter in one embodiment.

[0020] Figure 3 This is a schematic diagram of the encapsulation module in one embodiment.

[0021] Figure 4 This is a schematic diagram showing the connection between the signal electrode and the printed circuit board electrode of a superconducting quantum chip according to one embodiment. Detailed Implementation

[0022] This invention provides a superconducting quantum chip, packaging module, and processor for achieving uniform readout parameters. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] In common superconducting qubit readout schemes, the readout cavity and a broadband Bosell filter are coupled via capacitance or mutual inductance. The readout port of the Bosell filter is connected to a bonding plate at the chip edge via a coplanar waveguide transmission line, and then wire-bonded to the corresponding port on the printed circuit board. The impedance matching state at the readout port directly affects the effective bandwidth of the filter, and thus determines the effective linewidth of the readout cavity. Due to the high impedance of the wires, standing wave modes are easily formed between the output port of the Bosell filter and the wires, causing a significant deviation between the actual linewidth of the Bosell filter and the readout cavity and the design value.

[0024] In existing technologies, even with meticulously designed layouts of the Bosell filter and readout cavity, the manufactured chip performance (such as the filter's center frequency and bandwidth) can deviate unpredictably and randomly from the simulated design values ​​due to the lack of consideration for the resonant relationship between the connection transmission line length and wavelength. This difference is significant (typically >±10%). This "uncertainty" phenomenon leads to a high reliance on trial and error in R&D, resulting in low yield rates.

[0025] In multi-qubit chips, the performance differences (non-uniformity) of each channel are the core bottleneck restricting the scalability of quantum processors. Traditional methods attempt to compensate for these differences through post-processing calibration, but this is only a temporary solution and the complexity increases explosively with the number of qubits.

[0026] Due to random performance drift, engineers often need to go through multiple cycles of "design-tape-testing-adjustment" to obtain a barely usable chip, which is time-consuming and costly.

[0027] In multi-qubit superconducting quantum chips, non-uniformity of readout parameters reduces the readout quality of qubits and limits the improvement of overall chip performance.

[0028] Based on this, this embodiment provides a superconducting quantum chip that achieves uniform readout parameters, such as... Figure 1 As shown, it includes: Bossel filter 5, wherein the Bossel filter 5 is a half-wavelength resonant cavity structure with both ends grounded; Reading cavity 6 is coupled to the Bosell filter 5 via mutual inductance; At least one quantum bit 8 is coupled to the readout cavity 6; Output signal plate 3 and input signal plate 10; the output signal plate 3 is connected to the Bosell filter 5 via a first signal transmission line 4; the input signal plate 10 is connected to the Bosell filter 5 via a second signal transmission line 9; Wherein, the length of the first signal transmission line 4 is consistent and avoids odd multiples of the quarter wavelength corresponding to the operating frequency of the Bosell filter 5; and / or the length of the second signal transmission line 9 is consistent and avoids odd multiples of the quarter wavelength corresponding to the operating frequency of the Bosell filter 5, so as to suppress standing wave modes.

[0029] It should be noted that this embodiment controls the geometric length of the first signal transmission line 4 and the second signal transmission line 9. This mandatory requirement ensures that their electrical lengths avoid these "dangerous multiples" that can lead to resonance, thereby eliminating the conditions for the formation of standing waves at the source and preventing the drift of filter bandwidth and frequency. This ensures that different filters and their coupled readout cavities have uniform bandwidth.

[0030] This embodiment completely eliminates the inherent performance instability caused by transmission line resonance. This allows key parameters such as the frequency and bandwidth of the Bosell filter and readout cavity to be strictly stabilized near their design values, significantly reducing performance deviations that are difficult to control in traditional processes to a predictable and acceptable range. It transforms the original "trial-and-error" R&D model, which relied on repeated tape-outs, testing, and adjustments, into a first-round design based on defined physical rules, significantly shortening the chip development cycle and reducing R&D costs. These rules are universal and reproducible. When all readout channels on the chip follow this same rule during the design phase, a physically identical, resonance-free starting point is established for all channels, which is the fundamental prerequisite for achieving performance consistency between channels subsequently.

[0031] This embodiment creatively applies the classical microwave transmission line resonance theory to solve the problem of superconducting quantum chips. Its technical principle lies not only in "avoiding resonance," but also in accurately identifying the specific conditions under which resonance occurs and its differentiated behavior at specific ports. In the Bosell filter-readout cavity system of the superconducting quantum chip of this invention, when the electrical length of the transmission line connected to this port is exactly an odd multiple of a quarter wavelength of the signal (λ / 4) (e.g., λ / 4, 3λ / 4, etc.), this port is located precisely at the antinode of the voltage standing wave, resulting in extremely high impedance. This causes most of the signal to be reflected, forming a strong standing wave and causing the filter bandwidth to deviate significantly from the design value. Similarly, the input port, according to its design, is sensitive to specific modes of standing waves (e.g., avoiding odd multiples of λ / 4). This invention is the first to explicitly distinguish that the output port needs to avoid odd multiples, while the input port, under specific configurations, needs to avoid odd multiples. This differentiation rule stems from an in-depth analysis of the boundary conditions of Bosell filters. Therefore, this invention eliminates random drift at its source: transforming the deviation of readout cavity bandwidth and frequency from a difficult-to-predict and controllable random state (typically >±10%) into a deterministic state that can be precisely predicted and avoided through design, achieving a deviation of <±5%, significantly improving performance consistency. It imparts high design predictability: designers can ensure electrical performance during the drafting stage, drastically reducing the number of repeated tape-out verifications and lowering R&D cycle and cost by approximately 50% or more. It provides a physical basis for achieving multi-bit uniformity: this rule applies to every identical structure on the chip, providing a unified, resonant-free starting point for all readout channels, a prerequisite for subsequent channel-to-channel consistency.

[0032] In a preferred embodiment, when the connection between the first signal transmission line 4 and the Bossel filter 5 is located near the short-circuit end of the Bossel filter 5, the length of the first signal transmission line 4 avoids an odd multiple of a quarter wavelength corresponding to the operating frequency of the Bossel filter 5. When the connection between the second signal transmission line 9 and the Bossel filter 5 is located near the short-circuit end of the Bossel filter 5, the length of the second signal transmission line 9 avoids an odd multiple of a quarter wavelength corresponding to the operating frequency of the Bossel filter 5.

[0033] It should be noted that the wire bonding point is a high-impedance node. When the connection between the first signal transmission line 4 and the Bossel filter 5 is located at the open end of the Bossel filter 5, the connection point is also high impedance, and the standing wave mode formed between the two high-impedance points is an even multiple of a quarter wavelength. When the connection between the first signal transmission line 4 and the Bossel filter 5 is located at the short-circuit end of the Bossel filter 5, the connection point is also low impedance, and the standing wave mode formed between the high-low impedance points is an odd multiple of a quarter wavelength. Chip design must avoid the formation of standing wave modes on signal transmission lines to ensure that the parameters of the Bossel filter meet the design values.

[0034] In a preferred embodiment, the Bosell filter 5 has a characteristic bandwidth of 300MHz and a center frequency of 5-7GHz. Its bandwidth is determined by the coupling position between the output port signal first signal transmission line 4 and the filter.

[0035] It should be noted that the current mainstream multi-qubit chip readout frequency is 5-7 GHz (approximately 6 GHz). A single Bosell filter couples 6-8 readout cavities, with a frequency spacing of 30-50 MHz between them. A Bosell filter bandwidth of 300 MHz can cover all readout cavities. If the Bosell filter bandwidth is too small, it can couple too few readout cavities; if the bandwidth is too large, the Bosell filter does not adequately protect the coherence of the qubits.

[0036] In a preferred embodiment, such as Figure 2 As shown, the first signal transmission line 4 and the second signal transmission line 9 are both coplanar waveguide structures with a characteristic impedance of 50Ω and a linewidth of 4-20μm.

[0037] It should be noted that this embodiment uses a 50Ω standard impedance to ensure impedance continuity throughout the entire signal link from the chip to the PCB and then to external instruments, minimizing cascade reflections. Coplanar waveguide structure: Fully compatible with superconducting thin-film processes, its "signal line-ground-ground" structure facilitates integration with filters, cavities, and other planar components, and its field distribution helps suppress radiation loss. Linewidth 4-20μm: This range precisely corresponds to the capabilities of standard photolithography processes and the process window requirements for superconducting thin film thickness and dielectric layer thickness while maintaining a 50Ω impedance. It is a core parameter for achieving a perfect match between electrical design and manufacturing processes. Therefore, this embodiment ensures the feasibility of the design: ensuring that innovative electrical designs can be implemented with high precision and high yield through mature semiconductor micro / nano fabrication processes; guaranteeing consistency in mass production: standardized structure and process parameters ensure highly repeatable RF performance across different batches of chips; reducing technology adoption barriers and costs: customers or foundries can implement this invention on existing production lines without developing entirely new processes, accelerating technology transfer and product launch.

[0038] In a preferred embodiment, the mutual inductive coupling strength between the reading cavity 6 and the Bosell filter 5 is 5-10 pH. It can be 5 pH, 6 pH, 7 pH, 8 pH, 9 pH, or 10 pH.

[0039] This embodiment also provides a packaging module, such as Figure 3 , Figure 4 As shown, it includes: A superconducting quantum chip for achieving uniform readout parameters through multiple channels; the superconducting quantum chip for achieving uniform readout parameters includes an output signal plate 3 and an input signal plate 10; Printed circuit board electrode 1; Multiple parallel leads 2 connect the printed circuit board electrode 1 and the output signal electrode 3 or the input signal electrode 10. The length and number of parallel connections of the lead wires 2 connecting each output signal plate 3 or input signal plate 10 to the printed circuit board plate 1 are kept consistent.

[0040] It should be noted that this embodiment integrates the superconducting quantum chip and the printed circuit board electrode into a single physical entity. This structure significantly reduces parasitic inductance in the packaging process, thereby weakening the standing wave mode on the output transmission line, solving the impedance mismatch problem caused by excessive lead inductance in traditional packaging, and improving the flatness of signal transmission. Existing technologies often struggle to guarantee the consistency of readout parameters for multi-bit chips. This invention addresses this by locking the length and characteristic impedance of each transmission line during the superconducting quantum chip design and strictly controlling the length and parallel number of each lead during the packaging stage. This collaborative design across chip manufacturing and packaging processes eliminates electrical differences between multiple channels at the physical source, ensuring uniform bandwidth for different filters and their coupled readout cavities.

[0041] In one embodiment, the lead 2 is made of superconducting material, with a length of 1-3 mm and a diameter of 25 μm.

[0042] The current mainstream wire bonding equipment uses a wire diameter of 25um, and the wire length depends on the distance between the chip port and the PCB port, which is generally 1-3mm, providing better matching.

[0043] In one embodiment, the lead wire 2 is made of pure aluminum.

[0044] In this embodiment, pure aluminum is in a superconducting state at extremely low temperatures (<1K), and its resistance is zero, which fundamentally eliminates the ohmic loss of the lead wire.

[0045] In a preferred embodiment, the length of the output signal plate 3 or the input signal plate 10 is 0.2-0.4 mm and the width is 0.1-0.3 mm; the length of the printed circuit board plate 1 is 0.6-1.5 mm and the width is 0.2-0.4 mm.

[0046] This embodiment also provides a superconducting quantum processor, including: a packaging module; The control and reading circuit is connected to the electrode plate of the printed circuit board.

[0047] This embodiment ensures uniform bandwidth for different filters and their coupled readout cavities by controlling the transmission line length from the input / output ports of the Bosell filter to the leads. By avoiding integer multiples of a quarter of the readout signal wavelength in the transmission line length, current nodes are prevented at the leads, reducing the impact of impedance mismatch on filter performance. Furthermore, the equivalent inductance is reduced by connecting multiple leads in parallel, further suppressing impedance mismatch effects. This scheme has a simple structure, requires no additional impedance matching devices, and effectively achieves uniformity of readout parameters, thereby improving the overall performance of the quantum processor.

[0048] Finally, it should be noted that the purpose of disclosing the embodiments is to help further understand the present invention. However, those skilled in the art will understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the scope of protection of the present invention is defined by the claims.

Claims

1. A superconducting quantum chip for achieving uniform readout parameters, characterized in that, include: Bossel filter (5), wherein the Bossel filter (5) is a half-wavelength resonant cavity structure with both ends grounded; The reading cavity (6) is coupled to the Bosell filter (5) through mutual inductance; At least one quantum bit (8) is coupled to the readout cavity (6); Output signal plate (3) and input signal plate (10); the output signal plate (3) is connected to the Bosell filter (5) through a first signal transmission line (4); the input signal plate (10) is connected to the Bosell filter (5) through a second signal transmission line (9); Wherein, the length of the first signal transmission line (4) is consistent and avoids odd multiples of a quarter wavelength corresponding to the operating frequency of the Bosell filter (5); and / or the length of the second signal transmission line (9) is consistent and avoids odd multiples of a quarter wavelength corresponding to the operating frequency of the Bosell filter (5).

2. The superconducting quantum chip for achieving uniform readout parameters according to claim 1, characterized in that, When the connection between the first signal transmission line (4) and the Bossel filter (5) is located near the short-circuit end of the Bossel filter (5), the length of the first signal transmission line (4) avoids an odd multiple of a quarter wavelength corresponding to the operating frequency of the Bossel filter (5). When the connection point between the second signal transmission line (9) and the Bossel filter (5) is located near the short-circuit end of the Bossel filter (5), the length of the second signal transmission line (9) avoids an odd multiple of a quarter wavelength corresponding to the operating frequency of the Bossel filter (5).

3. A superconducting quantum chip for achieving uniform readout parameters according to claim 2, characterized in that, The Bosell filter (5) has a characteristic bandwidth of 300MHz and a center frequency of 5-7GHz.

4. A superconducting quantum chip for achieving uniform readout parameters according to claim 2, characterized in that, The first signal transmission line (4) and the second signal transmission line (9) are both coplanar waveguide structures with a characteristic impedance of 50Ω and a line width of 4-20μm.

5. A superconducting quantum chip for achieving uniform readout parameters according to claim 1, characterized in that, The mutual inductive coupling strength between the reading cavity (6) and the Bosell filter (5) is 5-10 pH.

6. A packaging module for a superconducting quantum chip that achieves uniform readout parameters, characterized in that, include: The superconducting quantum chip that achieves uniform readout parameters according to any one of claims 1-5; the superconducting quantum chip that achieves uniform readout parameters includes an output signal plate (3) and an input signal plate (10). Printed circuit board electrode (1); Multiple parallel leads (2) connect the printed circuit board electrode (1) and the output signal electrode (3) or the input signal electrode (10). The length and number of parallel connections of the lead wires (2) connecting each output signal plate (3) or input signal plate (10) to the printed circuit board plate (1) are kept consistent.

7. The packaging module for a superconducting quantum chip that achieves uniform readout parameters according to claim 6, characterized in that, The lead wire (2) is made of superconducting material, with a length of 1-3 mm and a diameter of 25 μm.

8. The packaging module for a superconducting quantum chip that achieves uniform readout parameters according to claim 6, characterized in that, The lead wire (2) is made of pure aluminum.

9. The packaging module for a superconducting quantum chip that achieves uniform readout parameters according to claim 6, characterized in that, The length of the output signal plate (3) or the input signal plate (10) is 0.2-0.4 mm and the width is 0.1-0.3 mm; the length of the printed circuit board plate (1) is 0.6-1.5 mm and the width is 0.2-0.4 mm.

10. A superconducting quantum processor, characterized in that, include: A packaging module for a superconducting quantum chip that achieves uniform readout parameters, as described in any one of claims 6-9; The control and reading circuit is connected to the electrode plate of the printed circuit board.

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