Method and system for controlling superconducting quantum chip bit frequency

Abstract

The application provides a superconducting quantum chip bit frequency regulation method and system, and relates to the technical field of superconducting quantum chip bit frequency regulation. The regulation method comprises the following steps: measuring an initial resistance value of a Josephson junction on a superconducting quantum chip in an initial state; controlling a temperature controller to adjust a heating temperature and a heating time according to the initial resistance value and a target resistance value of the Josephson junction, so as to perform global water bath heating annealing on the Josephson junction through heat conduction of a preset organic solvent, regulate the resistance value of the Josephson junction, and regulate the superconducting quantum chip bit frequency. The application replaces the traditional high-temperature global vacuum annealing process with a low-temperature water bath heating process, can keep a relatively consistent oxygen atom diffusion degree, avoids uneven resistance distribution caused by local overheating or overcooling, and realizes efficient and stable regulation of the superconducting quantum bit frequency.

Description

Technical Field

[0001] This application relates to the technical field of bit frequency modulation of superconducting quantum chips, and more specifically, to a method and system for modulating the bit frequency of a superconducting quantum chip. Background Technology

[0002] Superconducting quantum computing is one of the more promising quantum computing technologies. In superconducting quantum computing, the frequency of the superconducting quantum chip's qubits is crucial. Primarily determined by the critical current of the Josephson junction and its room temperature resistance Decide.

[0003] However, the barrier layer of a Josephson junction (e.g., using a superconductor / insulator / superconductor three-layer structure) is typically formed through thermal oxidation or plasma oxidation processes. These oxidation processes are susceptible to fluctuations in chamber pressure, ambient temperature, and oxidation time. These fluctuations can lead to changes in the room temperature resistance of the Josephson junction. Deviations from their target design values ​​directly affect the bit frequency of the superconducting quantum chip. The precision and consistency of quantum chip manufacturing are crucial. Therefore, after the quantum chip is manufactured, the room temperature resistance is assessed. Effective control of the bit frequency of superconducting quantum chips It is of great significance.

[0004] For resistance control of Josephson junctions, existing technologies generally employ a combined control scheme of "global coarse adjustment + local fine adjustment." For example, a large-scale, coarse adjustment is first achieved using a global vacuum annealing process. Then, a localized, high-precision fine adjustment is achieved through a localized laser annealing process. The global vacuum annealing typically needs to be performed in a rapid thermal annealing furnace, which requires multi-zone infrared lamp heating and operation in an inert gas atmosphere such as high-purity argon to prevent oxidation of the quantum chip at high temperatures. Furthermore, closed-loop temperature control is achieved using built-in thermocouples.

[0005] However, the inventors of this application have discovered that the above-mentioned resistance control method still has the following technical problems: 1. Insufficient process controllability: The existing global vacuum annealing process is relatively complex to operate, and it is difficult to accurately control the heating rate, cooling rate and heating time in the vacuum chamber.

[0006] 2. High equipment and application costs: Existing global vacuum annealing methods have relatively demanding requirements for hardware equipment, and must rely on rapid thermal annealing furnaces and supporting vacuum / inert atmosphere control systems, resulting in high equipment costs and maintenance complexity.

[0007] The content in the background section is merely technology known to the public and does not necessarily represent existing technology in this field. Summary of the Invention

[0008] This application provides a method and system for controlling the bit frequency of a superconducting quantum chip, aiming to solve at least one of the technical problems mentioned in the background art.

[0009] According to one aspect of this application, a method for controlling the bit frequency of a superconducting quantum chip is provided, comprising: placing the superconducting quantum chip in a water bath container, wherein the water bath container is pre-filled with a preset organic solvent; placing the water bath container on a hot plate, wherein the heating temperature and heating time of the hot plate are adjusted by a temperature controller electrically connected to the hot plate; measuring the initial resistance value of the Josephson junction on the superconducting quantum chip in its initial state; and controlling the temperature controller to adjust the heating temperature and heating time according to the initial resistance value and the target resistance value of the Josephson junction, so as to perform global heating annealing of the Josephson junction by water bath method through the thermal conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and controlling the bit frequency of the superconducting quantum chip.

[0010] According to some embodiments of this application, controlling the temperature controller to adjust the heating temperature and heating time based on the initial resistance value and the target resistance value of the Josephson junction includes: determining an adjustment resistance value based on the initial resistance value and the target resistance value; determining an adjustment ratio based on the adjustment resistance value and the initial resistance value; controlling the heating temperature of the hot plate to a first temperature range and the heating time to a first time range when the adjustment ratio is less than a first threshold; and controlling the heating temperature of the hot plate to a second temperature range and the heating time to a second time range when the adjustment ratio is not less than the first threshold.

[0011] According to some embodiments of this application, the temperature controller is a PID controller.

[0012] According to some embodiments of this application, the preset organic solvent is an electronic-grade N-methylpyrrolidone solution.

[0013] According to some embodiments of this application, the purity of the electronic grade N-methylpyrrolidone solution is greater than 99.9%.

[0014] According to another aspect of this application, this application provides a system for regulating the bit frequency of a superconducting quantum chip, including a water bath container, a hot plate, a temperature controller, a resistance measurement module, and a central control module. The water bath container is pre-filled with a preset organic solvent for holding the superconducting quantum chip; the water bath container is placed on the hot plate; the temperature controller is electrically connected to the hot plate and is used to adjust the heating temperature and heating time of the hot plate; the resistance measurement module is used to measure the initial resistance value of the Josephson junction in its initial state; the central control module is electrically connected to the resistance measurement module and the temperature controller, and controls the temperature controller to adjust the heating temperature and heating time based on the initial resistance value and the target resistance value of the Josephson junction, so as to perform global heating annealing of the Josephson junction through the heat conduction of the preset organic solvent in a water bath, thereby regulating the resistance value of the Josephson junction and thus regulating the bit frequency of the superconducting quantum chip.

[0015] According to some embodiments of this application, the central control module determines the adjustment resistance value based on the initial resistance value and the target resistance value; the central control module determines the adjustment ratio based on the adjustment resistance value and the initial resistance value; when the adjustment ratio is less than a first threshold, the central control module controls the heating temperature of the hot plate to a first temperature range and the heating time to a first time range; when the adjustment ratio is not less than the first threshold, the central control module controls the heating temperature of the hot plate to a second temperature range and the heating time to a second time range.

[0016] According to some embodiments of this application, the temperature controller is a PID controller.

[0017] According to some embodiments of this application, the preset organic solvent is an electronic-grade N-methylpyrrolidone solution.

[0018] According to some embodiments of this application, the purity of the electronic grade N-methylpyrrolidone solution is greater than 99.9%.

[0019] Beneficial effects This application places a superconducting quantum chip in a water bath container pre-filled with a preset organic solvent. The water bath container is then placed on a hot plate, and the heating temperature and heating time of the hot plate are regulated by a temperature controller electrically connected to the hot plate. This application also measures the initial resistance value of the Josephson junction in its initial state. Based on the initial resistance value and the target resistance value of the Josephson junction, the hot plate temperature and heating time are controlled to perform global heating annealing of the Josephson junction via the heat conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and thus regulating the bit frequency of the superconducting quantum chip.

[0020] This application provides a water bath heating environment for the resistance control of Josephson junctions by using the liquid phase heat conduction of a preset organic solvent. The water bath heating process replaces the traditional high-temperature global vacuum annealing process. The uniform temperature characteristics (uniform heat transfer) of the preset organic solvent can ensure that all Josephson junctions on the superconducting quantum chip experience the same amount of heating, maintain a consistent degree of oxygen atom diffusion, and avoid uneven resistance distribution caused by local overheating or overcooling.

[0021] Compared to traditional global vacuum annealing, gentle and uniform liquid-phase heat conduction heating avoids thermal stress caused by rapid temperature rise and fall, preventing structural damage to the barrier layer during oxygen diffusion. Furthermore, the pre-set organic solvent continuously cleans the superconducting quantum chip surface and isolates it from oxygen during heating, ensuring that the oxygen atom diffusion mechanism is not interfered with by surface contamination or unintended oxidation.

[0022] This application only requires a conventional hot plate and a standard ventilation environment to achieve resistance control, eliminating the need for complex equipment such as rapid thermal annealing furnaces, vacuum systems, or high-purity inert gas supply devices, thus reducing equipment investment and operation and maintenance costs. Furthermore, this application exhibits good process compatibility; the resistance control method can also be extended to superconducting quantum chips based on various material systems, including aluminum (Al)-based and niobium (Nb)-based materials. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating a method for controlling the bit frequency of a superconducting quantum chip according to an embodiment of this application is shown. Figure 2 This is another schematic flowchart illustrating a method for controlling the bit frequency of a superconducting quantum chip according to an embodiment of this application; Figure 3 A schematic diagram showing the bit frequency of a superconducting quantum chip according to an embodiment of this application; Figure 4 This application illustrates the coherence time (energy relaxation time) of a superconducting quantum bit in an embodiment of the present application. A schematic diagram of ( ); Figure 5 The superconducting quantum bit coherence time (decoherence time) of an embodiment of this application is shown. A schematic diagram of ( ); Figure 6 A schematic diagram of the resistance control system according to an embodiment of this application is shown.

[0025] Explanation of reference numerals in the attached figures: Water bath container 10; hot plate 20; temperature controller 30; resistance measurement module 40; central control module 50. Detailed Implementation

[0026] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0027] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.

[0028] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0029] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order.

[0030] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] What can be understood here is the bit frequency of the superconducting quantum chip. The expression can be: ; in, For the bit frequency of superconducting quantum chips, It is Planck's constant. For Josephson, To charge energy, The critical current, It is the room temperature resistance.

[0032] According to the above expression, the bit frequency of the superconducting quantum chip can be determined. With room temperature resistance Inversely proportional. Room temperature resistance An increase in will cause the critical current to rise. The reduction allows Josephson to The frequency of superconducting quantum chips decreases, which in turn leads to a reduction in the bit frequency. The decrease.

[0033] According to one aspect of this application, a method for controlling the bit frequency of a superconducting quantum chip is provided. For example... Figure 1 As shown, the method for controlling the bit frequency of the superconducting quantum chip may include steps S100-S400.

[0034] According to an example embodiment, this control method can be performed based on a control system for the bit frequency of a superconducting quantum chip.

[0035] According to the example embodiment, in step S100, the superconducting quantum chip is placed in a water bath container, which contains a preset organic solvent.

[0036] For example, the preset organic solvent is an organic solvent with cleaning, air isolation and uniform heat conduction functions.

[0037] This application forms a water bath system by placing a superconducting quantum chip in a water bath container. The water bath, based on a preset organic solvent, can simultaneously remove contaminants from the surface of the superconducting quantum chip and isolate it from air, thus avoiding contamination or interference with the control of junction resistance.

[0038] The pre-selected organic solvent has a high boiling point (e.g., 100℃-175℃) and a low vapor pressure, allowing it to completely immerse the superconducting quantum chip in a stable liquid phase during heating. This pre-selected organic solvent can form a continuous, dense physical barrier on the surface of the superconducting quantum chip, effectively isolating oxidizing components such as oxygen and water vapor in the air, and preventing unintended thermal oxidation or corrosion of the Josephson junction metal layer (usually an easily oxidized metal such as aluminum or niobium) on the superconducting quantum chip during heating.

[0039] The pre-selected organic solvent also possesses high specific heat capacity and good thermal conductivity, enabling it to serve as a liquid heat exchange medium. This allows heat transferred from the hot plate to the water bath to be rapidly and uniformly conducted to every part of the superconducting quantum chip. Compared to gases (such as the argon atmosphere in existing technologies) or vacuum environments, the liquid-phase heat exchange efficiency of this organic solvent can be increased by tens to hundreds of times, eliminating localized overheating or overcooling. With this configuration, this application can shorten the time required to reach thermal equilibrium and ensure intra-chip uniformity and inter-chip repeatability of resistance modulation effects.

[0040] For example, in this application, the water bath container is a chemically resistant and high-temperature resistant container used to contain a preset organic solvent and completely immerse the superconducting quantum chip in it, so as to perform global heating annealing of the Josephson junction by water bath method through liquid phase heat conduction.

[0041] For example, the preset organic solvent can be N-methylpyrrolidone (NMP).

[0042] Alternatively, the water bath container can be a high-temperature resistant quartz petri dish.

[0043] Optionally, the wall thickness of the water bath container is greater than or equal to 2 mm.

[0044] Optionally, before placing the superconducting quantum chip in the water bath container, the water bath container is preheated at a preset temperature (e.g., 180°C) for a preset duration (e.g., 2 hours) to remove organic residues on the water bath container.

[0045] In step S200, the water bath container is placed on the hot plate, and the heating temperature and heating time of the hot plate are adjusted by a temperature controller electrically connected to the hot plate.

[0046] For example, a water bath containing a superconducting quantum chip and a pre-set organic solvent is placed on the heating surface of a hot plate. This hot plate is a thermostatic hot plate with precise temperature control. To ensure good heat conduction efficiency, the bottom of the water bath is in close contact with the heating surface of the hot plate during placement.

[0047] Optionally, the temperature of the heating surface of the hot plate is uniform.

[0048] For example, the heating surface of the hot plate is provided with uniformly arranged heating elements, and the arrangement of these heating elements can be customized based on actual usage requirements.

[0049] On the one hand, the heating surface of the hot plate is divided into zones (such as a central temperature control zone and an edge temperature control zone) with heating elements, which can eliminate local hot and cold spots and maintain a uniform temperature on the heating surface. On the other hand, the heating temperature of the heating elements can be adjusted by a temperature controller electrically connected to the hot plate. The temperature controller adjusts the heating time and temperature of the heating elements in real time through the zones, thus maintaining a uniform temperature on the heating surface.

[0050] Optionally, the hot plate is equipped with dual thermocouples. When the heating temperature exceeds a preset threshold (such as 175°C), the temperature controller will cut off the power to the hot plate for safety protection.

[0051] Optionally, the heating / cooling rate of the hot plate can be less than or equal to 5°C / min. This setting can prevent the water bath container from cracking under high heating / cooling rates, or avoid affecting the on-chip uniformity of the Josephson junction resistance due to uneven local heating of the superconducting quantum chip.

[0052] In step S300, the control system measures the initial resistance value of the Josephson junction on the superconducting quantum chip in its initial state.

[0053] For example, the initial state is at room temperature, with the superconducting quantum chip in a state without any heating treatment. The initial resistance value is the resistance value of the Josephson junction of the superconducting quantum chip when it is not heated. .

[0054] For example, the control system can measure the resistance of the Josephson junction in its initial state based on a probe station (such as upper and lower probes contacting the upper and lower electrodes of the capacitor pads connected to the Josephson junction, respectively), and record this as the initial resistance value. .

[0055] In step S400, the control system controls the temperature controller to adjust the heating temperature and heating time according to the initial resistance value and the target resistance value of the Josephson junction, so as to perform global heating and annealing of the Josephson junction by water bath through the heat conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and controlling the bit frequency of the superconducting quantum chip.

[0056] It is understandable here that the Josephson junction in superconducting quantum chips typically uses Al / AlO₂. x Al (aluminum / alumina / aluminum) three-layer structure, of which AlO x The barrier layer is formed through thermal oxidation or plasma oxidation processes. After fabrication, the oxygen atom distribution within the barrier layer often exhibits a certain degree of inhomogeneity or local defect states. This non-ideal structure leads to a lower effective height of the electron tunneling barrier, thus affecting the room-temperature resistance of the Josephson junction. It deviates from its target design value.

[0057] During the water bath heating of the superconducting quantum chip using a hot plate and a pre-set organic solvent, oxygen atoms diffuse towards the center of the potential barrier, filling the weak regions of the barrier that previously contained defects or oxygen vacancies, thus enhancing the overall performance of the AlO2 quantum chip. x The oxygen concentration distribution in the barrier layer tends to become more uniform, and the uniformly distributed oxygen atoms form a more uniform high barrier layer. This redistribution of oxygen atoms is equivalent to increasing the width and height of the barrier that electrons need to overcome for tunneling, thus increasing the difficulty of electron tunneling. (The text then abruptly shifts to discussing the room temperature resistance of a Josephson junction.) It exhibits an exponential positive correlation with the effective height of the barrier layer. When the barrier layer becomes more uniform and the barrier height is higher, it is macroscopically manifested as a significant increase in junction resistance.

[0058] Therefore, this application uses a hot plate 20 and a preset organic solvent to heat the superconducting quantum chip in a water bath. This thermal excitation drives the oxygen atoms in the Josephson junction to redistribute within the barrier layer and diffuse toward the barrier center, thereby forming a more uniform and dense high barrier layer. This increases the difficulty of electron tunneling, thus enabling efficient and stable control of the resistance of the Josephson junction, and consequently, efficient and stable control of the superconducting quantum bit frequency.

[0059] In step S400, the target resistance value of the Josephson junction is the desired adjustment value of the Josephson junction. The control system will and Compare and calculate the adjustment resistor value ( In a water bath system, the change in resistance of a Josephson junction is positively correlated with both heating temperature and heating time (i.e., within a certain range, the higher the temperature and the longer the time, the greater the increase in resistance). The control system can adjust the resistance value accordingly. It automatically calculates the resistance value required to achieve the target resistance. Required heating temperature setting and heating time .

[0060] For example, when performing resistance regulation for the first time, the regulation system can use a test chip to calibrate the resistance-temperature-time curve.

[0061] Optionally, the heating temperature of the hot plate is lower than the boiling point of the preset organic solvent.

[0062] For example, heating the organic solvent to a temperature higher than the boiling point of the preset organic solvent will cause the preset organic solvent to boil, and boiling will lead to problems such as bubble formation, displacement of the superconducting quantum chip, or decomposition of the preset organic solvent.

[0063] For example, a reserved test junction can be set on the superconducting quantum chip, so that heating can be paused and the resistance of the Josephson junction can be measured quickly during the global heating annealing process of water bath method.

[0064] Optionally, the superconducting quantum chip shall not be subjected to more than three water bath global thermal annealing processes, and the change in resistance of the Josephson junction shall be less than 5% during a single process, at which point the heating of the superconducting quantum chip shall be stopped.

[0065] Optionally, after completing the global heating annealing using a water bath method, the superconducting quantum chip can be rinsed, dehydrated (e.g., rinsed with propanol, dehydrated with isopropanol), and dried. Then, the room temperature resistance of the Josephson junction is remeasured. And measure the bit frequency of the superconducting quantum chip. and coherence time (such as energy relaxation time) Coherence time This ensures the structural integrity of the Josephson knot.

[0066] Through the above embodiments, this application places the superconducting quantum chip in a water bath container pre-filled with a preset organic solvent. The water bath container is then placed on a hot plate, and the heating temperature and heating time of the hot plate are regulated by a temperature controller electrically connected to the hot plate. This application also measures the initial resistance value of the Josephson junction in its initial state. Based on the initial resistance value and the target resistance value of the Josephson junction, the temperature of the hot plate and the heating time are controlled to perform global heating and annealing of the Josephson junction via the heat conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and thus controlling the bit frequency of the superconducting quantum chip.

[0067] This application provides a water bath heating environment for the resistance control of Josephson junctions by using the liquid phase heat conduction of a preset organic solvent. The water bath heating process replaces the traditional high-temperature global vacuum annealing process. The uniform temperature characteristics (uniform heat transfer) of the preset organic solvent can ensure that all Josephson junctions on the superconducting quantum chip experience the same amount of heating, maintain a consistent degree of oxygen atom diffusion, and avoid uneven resistance distribution caused by local overheating or overcooling.

[0068] Compared to traditional global vacuum annealing, gentle and uniform liquid-phase heat conduction heating avoids thermal stress caused by rapid temperature rise and fall, preventing structural damage to the barrier layer during oxygen diffusion. Furthermore, the pre-set organic solvent continuously cleans the superconducting quantum chip surface and isolates it from oxygen during heating, ensuring that the oxygen atom diffusion mechanism is not interfered with by surface contamination or unintended oxidation.

[0069] This application only requires a conventional hot plate and a standard ventilation environment to achieve resistance control, eliminating the need for complex equipment such as rapid thermal annealing furnaces, vacuum systems, or high-purity inert gas supply devices, thus reducing equipment investment and operation and maintenance costs. Furthermore, this application exhibits good process compatibility; the resistance control method can also be extended to superconducting quantum chips based on various material systems, including aluminum (Al)-based and niobium (Nb)-based materials.

[0070] Optionally, such as Figure 2 As shown, step S400 may also include steps S410-S440.

[0071] In step S410, the control system determines the adjustment resistance value based on the initial resistance value and the target resistance value.

[0072] In step S420, the control system determines the adjustment ratio based on the adjustment resistance value and the initial resistance value.

[0073] For example, adjusting the resistance value for Adjustment ratio P is .

[0074] In step S430, when the adjustment ratio is less than the first threshold, the control system controls the heating temperature of the hot plate to a first temperature range and the heating time to a first time range.

[0075] In step S440, the control system controls the heating temperature of the hot plate to a second temperature range and the heating time to a second time range, provided that the adjustment ratio is not less than the first threshold.

[0076] For example, the control system can perform graded heat treatment control according to the adjustment ratio P to adapt to different resistance adjustment requirements.

[0077] According to an example embodiment, the first threshold can be preset based on the design parameters of the Josephson junction, process tolerance, and qubit frequency accuracy requirements; this application does not impose any limitations on this. For example, the first threshold can be 30%.

[0078] For example, when the adjustment ratio P is less than the first threshold (e.g., P is less than 30%), it is in a small-amplitude resistance adjustment mode. The control system then sends a first control command to the temperature controller, controlling the heating temperature of the hot plate to be within the first temperature range. The heating time is within the first time range. .

[0079] For example, The range can be [100℃, 130℃]. The range can be [5min, 15min].

[0080] First temperature range and the first time range Under mild heat treatment conditions, the thermal energy in the pre-set organic solvent can smoothly drive the oxygen atoms in the barrier layer to undergo local diffusion and rearrangement, achieving a small and precise increase in resistance value. Due to the low heating temperature and short time, the small-amplitude resistance adjustment mode can minimize the process cycle and improve processing efficiency while ensuring the accuracy of resistance control.

[0081] For example, when the adjustment ratio P is not less than the first threshold (e.g., P is greater than 30% and less than 50%), it is in a large-amplitude resistance adjustment mode. Then, the control system sends a second control command to the temperature controller to control the heating temperature of the hot plate to the second temperature range. The heating time is within the second time range. .

[0082] For example, The range can be (130℃, 175℃), The range can be (15min, 30min).

[0083] Second temperature range Second time range Under stronger heat treatment conditions, higher thermal energy provides a stronger driving force for oxygen atoms to diffuse towards the center of the barrier, and longer heating time ensures that the diffusion process is fully carried out, thereby forming a more uniform and higher barrier layer, achieving a significant increase in the resistance value.

[0084] It is understood here that this application includes, but is not limited to, two-level graded control. In some other embodiments, multiple thresholds (such as a second threshold, a third threshold, etc.) can be set to divide the control mode into three or more levels (e.g., fine-tuning mode, medium-tuning mode, emphasis mode), with each level corresponding to a different combination of temperature range and time range, in order to achieve more refined resistance control and meet the accuracy and efficiency requirements of different application scenarios.

[0085] This application uses an adjustment ratio P (i.e., the percentage of the initial resistance value to be adjusted) instead of the resistance value. Using the absolute value as the criterion for grading allows this graded control strategy to be applied to Josephson junctions with different design resistance values. Under proportional graded thermal processing control, both fall into the same control mode (e.g., small-amplitude control), obtaining matched thermal processing parameters. However, in absolute value-based schemes, different absolute values ​​may be misjudged as different levels, leading to improper resistance control. Therefore, this application can eliminate the scaling effect caused by differences in design resistance values, eliminating the need to recalibrate the threshold for each quantum chip and improving the versatility of the process.

[0086] The graded heat treatment control employed in this application allows for fine-tuning under mild conditions during small-scale adjustments, avoiding the risk of over-adjustment due to excessive heat budget. During large-scale adjustments, enhanced conditions provide sufficient thermal driving force, ensuring that the resistance can be reliably adjusted to the target resistance value, thereby achieving high process accuracy and controllability throughout the entire control range.

[0087] Staged thermal control also ensures that the supplied thermal budget matches the adjustment ratio of actual needs: small-scale adjustments avoid applying excessive heat energy, preventing unnecessary thermal shock to the Josephson junction barrier layer or other structures of the quantum chip. Large-scale adjustments provide sufficient thermal budget, ensuring the control effect while maintaining controllable thermal stress through the liquid-phase homogenization properties of organic solvents. This precise matching of the thermal budget can further reduce the risk of quantum chip damage and improve manufacturing yield.

[0088] Optionally, the temperature controller can be a PID controller (Proportional-Integral-Derivative).

[0089] For example, the heating surface of a hot plate can be spatially divided into multiple independent temperature control zones, including a central temperature control zone and an edge temperature control zone. Each temperature control zone is equipped with an independent heating element (such as a resistance wire or thin-film heater) and a corresponding temperature sensor (such as a thermocouple or platinum resistance thermometer). The PID controller receives real-time temperature information from each temperature control zone and independently calculates the control output for each zone.

[0090] For the edge temperature control zone, since its heat dissipation rate is significantly higher than that of the central temperature control zone (i.e., edge heat loss), the PID controller automatically identifies the temperature drop trend in this area. Under the proportional (P) term, the PID controller increases the heating power of the edge temperature control zone proportionally to the magnitude of the temperature deviation. Under the integral (I) term, the PID controller eliminates the long-term steady-state temperature error in the edge region. Under the derivative (D) term, the PID controller predicts the heat dissipation trend of the edge temperature control zone in advance based on the rate of temperature change and increases the heating power in advance before the temperature drops significantly, thereby achieving dynamic compensation.

[0091] As an example, during the heating process of the hot plate, in the initial stage of heating, the PID controller outputs maximum power to drive all temperature-controlled zones to heat up rapidly. When the central temperature-controlled zone approaches the preset temperature, the PID controller reduces its heating power to prevent overshoot. However, due to greater heat loss, the temperature of the edge temperature-controlled zones remains below the set value. The PID controller maintains or even increases the heating power of the edge areas through proportional and integral actions, forming an asymmetric power output mode of "stable center and enhanced edges".

[0092] Optionally, the temperature variation range of the heating surface of the hot plate is less than or equal to ±1℃.

[0093] Once the constant temperature phase begins, the PID controller monitors the temperature fluctuations in each zone in real time. When the PID controller detects a cooling trend in the edge area due to ambient airflow or operational disturbances, the derivative (D) term responds immediately, dynamically increasing the heating power of that temperature-controlled zone at the onset of cooling to suppress temperature fluctuations within ±1°C.

[0094] Through the above embodiments, this application, by setting a temperature controller, can independently control the heating temperature of the hot plate in zones, so that the temperature uniformity of the entire heating surface can reach ±1°C. This application can ensure that the heat transfer at the bottom of the water bath container has highly uniform boundary conditions, and can provide a stable and uniform thermal environment for the preset organic solvent in the water bath container and the superconducting quantum chip immersed in it.

[0095] Optionally, the preset organic solvent is an electronic-grade N-methylpyrrolidone solution. The purity of the electronic-grade N-methylpyrrolidone solution is greater than 99.9%.

[0096] For example, N-methylpyrrolidone is a polar aprotic solvent with a high boiling point (approximately 202°C), good thermal stability, excellent solubility, and chemical inertness to superconducting chip materials (such as aluminum, niobium, and alumina barrier layers). Its high purity of over 99.9% ensures that the preset organic solvent does not contain metal ions, particulate matter, or organic impurities that could potentially contaminate the surface of the quantum chip.

[0097] As an example, with the growth conditions of the Josephson junction fixed, the junction resistance of different sizes of the test chip was subjected to global heating annealing using a water bath method based on specific heating conditions (such as 130°C, 20 min). The resistance control process is shown in Table 1. Table 1. Comparison of resistance modulation for junction resistances of different sizes

[0098] As shown in Table 1, the resistance increase of junctions of different sizes after global heating annealing under specific heating conditions using a water bath method exhibits a relatively consistent rate of increase. Therefore, the method for controlling the bit frequency of the superconducting quantum chip provided in this application can achieve control over the junction resistance based on specific heating conditions.

[0099] As an example, let's assume a formal sample whose design parameters for its tunable qubit SQUID (Superconducting Quantum Interference Device) are: SQUID has a symmetry of 1:1; Josephson It is 16.88 GHz; Charging energy It is 0.184 GHz; Superconducting quantum chip bit frequency It is 4.8 GHz; Room temperature resistance of Josephson junction It is 7.94 kΩ.

[0100] Assuming the junction size of the formal sample is 290 nm (top electrode) × 200 nm (bottom electrode), the resistance regulation process of this junction under specific heating conditions (such as 130 °C, 20 min) is shown in Table 2: Table 2 Comparison of resistance modulation of junction resistance in formal samples

[0101] As shown in Table 2, the resistivity of the Josephson junction after global heating annealing using the water bath method is 7.98 kΩ, which is close to the room temperature resistivity of the Josephson junction. The design value is 7.94 kΩ. For example... Figure 3 As shown, in the above embodiments, the measured frequency range of the superconducting quantum chip qubits is 4.8 GHz to 5.073 GHz, which is close to the frequency range of the superconducting quantum chip qubits. The design frequency is 4.8GHz. For example... Figure 4 and Figure 5 As shown, in the above embodiment, the measured coherence time of the superconducting quantum bit is , Therefore, it can be seen that the resistance value of the Josephson junction and the bit frequency of the superconducting quantum chip after global heating annealing by the water bath method provided in this application are close to their design values, and the structure still retains its integrity.

[0102] According to another aspect of this application, this application also provides a system for controlling the bit frequency of a superconducting quantum chip. For example... Figure 6 As shown, the control system may include a water bath container 10, a hot plate 20, a temperature controller 30, a resistance measurement module 40, and a central control module 50.

[0103] For example, Figure 6 Only a schematic diagram of the components of the control system is shown, not a schematic diagram of the location connections.

[0104] According to the example embodiment, the superconducting quantum chip is placed in a water bath container 10, which contains a pre-prepared organic solvent.

[0105] For example, the preset organic solvent is an organic solvent with cleaning, air isolation and uniform heat conduction functions.

[0106] This application forms a water bath system by placing a superconducting quantum chip in a water bath container. The water bath, based on a preset organic solvent, can simultaneously remove contaminants from the surface of the superconducting quantum chip and isolate it from air, thus avoiding contamination or interference with the control of junction resistance.

[0107] The pre-selected organic solvent has a high boiling point (e.g., 100℃-175℃) and a low vapor pressure, allowing it to completely immerse the superconducting quantum chip in a stable liquid phase during heating. This pre-selected organic solvent can form a continuous, dense physical barrier on the surface of the superconducting quantum chip, effectively isolating oxidizing components such as oxygen and water vapor in the air, and preventing unintended thermal oxidation or corrosion of the Josephson junction metal layer (usually an easily oxidized metal such as aluminum or niobium) on the superconducting quantum chip during heating.

[0108] The pre-selected organic solvent also possesses high specific heat capacity and good thermal conductivity, enabling it to serve as a liquid heat exchange medium. This allows heat transferred from the hot plate to the water bath to be rapidly and uniformly conducted to every part of the fully immersed superconducting quantum chip. Compared to gases (such as the argon atmosphere in existing technologies) or vacuum environments, the liquid-phase heat exchange efficiency of this organic solvent can be increased by tens to hundreds of times, eliminating localized overheating or overcooling. With this configuration, this application can shorten the time required to reach thermal equilibrium and ensure intra-chip uniformity and inter-chip repeatability of resistance modulation effects.

[0109] For example, in this application, the water bath container 10 is a chemically resistant and high-temperature resistant container used to contain a preset organic solvent and completely immerse the superconducting quantum chip in it, so as to perform global heating annealing of the Josephson junction by water bath method through liquid phase heat conduction.

[0110] For example, the preset organic solvent can be N-methylpyrrolidone (NMP).

[0111] Optionally, the water bath container 10 can be a high-temperature resistant quartz petri dish.

[0112] Optionally, the wall thickness of the water bath container 10 is greater than or equal to 2 mm.

[0113] Optionally, before placing the superconducting quantum chip in the water bath container 10, the water bath container 10 is preheated at a preset temperature (e.g., 180°C) for a preset duration (e.g., 2 hours) to remove organic residues on the water bath container 10.

[0114] According to the example embodiment, the water bath container 10 is placed on the hot plate 20, and the heating temperature and heating time of the hot plate 20 are adjusted by the temperature controller 30 electrically connected to the hot plate 20.

[0115] For example, a water bath container 10 containing a superconducting quantum chip and a pre-set organic solvent is placed on the heating surface of a hot plate 20. This hot plate 20 can be a thermostatic hot plate with precise temperature control. To ensure good heat transfer efficiency, the bottom of the water bath container is in close contact with the heating surface of the hot plate during placement.

[0116] Optionally, the temperature of the heating surface of the hot plate 20 is uniform.

[0117] For example, the heating surface of the hot plate 20 is provided with uniformly arranged heating elements, and the arrangement of these heating elements can be customized based on actual usage requirements.

[0118] On the one hand, the heating surface of the hot plate 20 is divided into zones (such as a central temperature control zone and an edge temperature control zone) with heating elements, which can eliminate local hot and cold spots and maintain the temperature uniformity of the heating surface. On the other hand, the heating temperature of the heating elements can be adjusted by a temperature controller 30 electrically connected to the hot plate 20. The temperature controller 30 adjusts the heating time and heating temperature of the heating elements in real time through the zones, and the zones compensate for heat loss in real time, which can maintain the temperature uniformity of the heating surface.

[0119] Optionally, the hot plate 20 is equipped with dual thermocouples. When the heating temperature exceeds a preset threshold (e.g., 175°C), the temperature controller 30 controls the hot plate 20 to cut off the power for safety protection.

[0120] Optionally, the heating / cooling rate of the hot plate 20 can be less than or equal to 5°C / min. This setting can prevent the water bath container 10 from cracking under high heating / cooling rates, or avoid the superconducting quantum chip from affecting the on-chip uniformity of the Josephson junction resistance due to uneven local heating.

[0121] According to an example embodiment, the resistance measurement module 40 measures the initial resistance value of the Josephson junction on the superconducting quantum chip in its initial state.

[0122] For example, the initial state is at room temperature, with the superconducting quantum chip in a state without any heating treatment. The initial resistance value is the resistance value of the Josephson junction of the superconducting quantum chip when it is not heated. .

[0123] For example, the resistance measurement module 40 can measure the resistance value of the Josephson junction in its initial state based on a probe station (such as upper and lower probes contacting the upper and lower electrodes of the capacitor pads connected to the Josephson junction, respectively), and record it as the initial resistance value. .

[0124] According to the example embodiment, the central control module 50 controls the temperature controller to adjust the heating temperature and heating time based on the initial resistance value and the target resistance value of the Josephson junction, so as to perform global heating and annealing of the Josephson junction by water bath through the heat conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and controlling the bit frequency of the superconducting quantum chip.

[0125] It is understandable here that the Josephson junction in superconducting quantum chips typically uses Al / AlO. x Al (aluminum / alumina / aluminum) three-layer structure, of which AlO x The barrier layer is formed through thermal oxidation or plasma oxidation processes. After fabrication, the oxygen atom distribution within the barrier layer often exhibits a certain degree of inhomogeneity or local defect states. This non-ideal structure leads to a lower effective height of the electron tunneling barrier, thus affecting the room-temperature resistance of the Josephson junction. It deviates from its target design value.

[0126] During the water bath heating of the superconducting quantum chip using hot plate 20 and a pre-set organic solvent, oxygen atoms diffuse towards the center of the potential barrier, filling the weak regions of the barrier that originally had defects or oxygen vacancies, thus enhancing the overall performance of the AlO2 quantum chip. x The oxygen concentration distribution in the barrier layer tends to become more uniform, and the uniformly distributed oxygen atoms form a more uniform high barrier layer. This redistribution of oxygen atoms is equivalent to increasing the width and height of the barrier that electrons need to overcome for tunneling, thus increasing the difficulty of electron tunneling. (The text then abruptly shifts to discussing the room temperature resistance of a Josephson junction.) It exhibits an exponential positive correlation with the effective height of the barrier layer. When the barrier layer becomes more uniform and the barrier height is higher, it is macroscopically manifested as a significant increase in junction resistance.

[0127] Therefore, this application uses a hot plate 20 and a preset organic solvent to heat the superconducting quantum chip in a water bath. This thermal excitation drives the oxygen atoms in the Josephson junction to redistribute within the barrier layer and diffuse toward the barrier center, thereby forming a more uniform and dense high barrier layer. This increases the difficulty of electron tunneling, thus enabling efficient and stable control of the resistance of the Josephson junction, and consequently, efficient and stable control of the superconducting quantum bit frequency.

[0128] The target resistance value of the Josephson junction is the desired regulation value of the Josephson junction. The central control module 50 will... and Compare and calculate the adjustment resistor value ( In a water bath system, the change in resistance of a Josephson junction is positively correlated with both heating temperature and heating time (i.e., within a certain range, the higher the temperature and the longer the time, the greater the increase in resistance). The central control module 50 can adjust the resistance value accordingly. It automatically calculates the resistance value required to achieve the target resistance. Required heating temperature setting and heating time .

[0129] For example, when initially adjusting the resistance, the adjustment system can use a test chip to calibrate the resistance-temperature-time curve.

[0130] Optionally, the heating temperature of the hot plate 20 is lower than the boiling point of the preset organic solvent.

[0131] For example, heating the organic solvent to a temperature higher than the boiling point of the preset organic solvent will cause the preset organic solvent to boil, and boiling will lead to problems such as bubble formation, displacement of the superconducting quantum chip, or decomposition of the preset organic solvent.

[0132] For example, a reserved test junction can be set on the superconducting quantum chip, so that heating can be paused and the resistance of the Josephson junction can be measured quickly during the global heating annealing process of water bath method.

[0133] Optionally, the superconducting quantum chip shall not be subjected to global heating annealing by water bath method more than three times, and the change in resistance value of Josephson junction shall be less than 5% during a single treatment, then the heating of the superconducting quantum chip shall be stopped.

[0134] Optionally, after completing the global heating annealing using a water bath method, the superconducting quantum chip can be rinsed, dehydrated (e.g., rinsed with propanol and dehydrated with isopropanol), and dried. Then, the room temperature resistance of the Josephson junction is remeasured. And measure the bit frequency of the superconducting quantum chip. and coherence time (such as energy relaxation time) Coherence time This ensures the structural integrity of the Josephson knot.

[0135] This application provides a water bath heating environment for the resistance control of Josephson junctions by using the liquid phase heat conduction of a preset organic solvent. The water bath heating process replaces the traditional high-temperature global vacuum annealing process. The uniform temperature characteristics (uniform heat transfer) of the preset organic solvent can ensure that all Josephson junctions on the superconducting quantum chip experience the same amount of heating, maintain a consistent degree of oxygen atom diffusion, and avoid uneven resistance distribution caused by local overheating or overcooling.

[0136] Compared to traditional global vacuum annealing, gentle and uniform liquid-phase heat conduction heating avoids thermal stress caused by rapid temperature rise and fall, preventing structural damage to the barrier layer during oxygen diffusion. Furthermore, the pre-set organic solvent continuously cleans the superconducting quantum chip surface and isolates it from oxygen during heating, ensuring that the oxygen atom diffusion mechanism is not interfered with by surface contamination or unintended oxidation.

[0137] This application only requires a conventional hot plate and a standard ventilation environment to achieve resistance control, eliminating the need for complex equipment such as rapid thermal annealing furnaces, vacuum systems, or high-purity inert gas supply devices, thus reducing equipment investment and operation and maintenance costs. Furthermore, this application exhibits good process compatibility; the resistance control method can also be extended to superconducting quantum chips based on various material systems, including aluminum (Al)-based and niobium (Nb)-based materials.

[0138] Optionally, the central control module 50 determines the adjustment resistance value based on the initial resistance value and the target resistance value.

[0139] The central control module 50 determines the adjustment ratio based on the adjustment resistance value and the initial resistance value.

[0140] For example, adjusting the resistance value for Adjustment ratio P is .

[0141] When the adjustment ratio is less than the first threshold, the central control module 50 controls the heating temperature of the hot plate to be within the first temperature range and the heating time to be within the first time range.

[0142] When the adjustment ratio is not less than the first threshold, the central control module 50 controls the heating temperature of the hot plate to be within the second temperature range and the heating time to be within the second time range.

[0143] For example, the central control module 50 can perform graded heat treatment control according to the adjustment ratio P to adapt to different resistance adjustment requirements.

[0144] According to an example embodiment, the first threshold can be preset based on the design parameters of the Josephson junction, process tolerance, and qubit frequency accuracy requirements; this application does not impose any limitations on this. For example, the first threshold can be 30%.

[0145] For example, when the adjustment ratio P is less than the first threshold (e.g., P is less than 30%), it is in a small-amplitude resistance adjustment mode. Then, the central control module 50 sends a first control command to the temperature controller 30, controlling the heating temperature of the hot plate 20 to be within the first temperature range. The heating time is within the first time range. .

[0146] For example, The range can be [100℃, 130℃]. The range can be [5min, 15min].

[0147] First temperature range and the first time range Under mild heat treatment conditions, the thermal energy in the pre-set organic solvent can smoothly drive the oxygen atoms in the barrier layer to undergo local diffusion and rearrangement, achieving a small and precise increase in resistance value. Due to the low heating temperature and short time, the small-amplitude resistance adjustment mode can minimize the process cycle and improve processing efficiency while ensuring the accuracy of resistance control.

[0148] For example, when the adjustment ratio P is not less than the first threshold (e.g., P is greater than 30% and less than 50%), it is in a large-amplitude resistance adjustment mode. Then, the central control module 50 sends a second control command to the temperature controller to control the heating temperature of the hot plate to the second temperature range. The heating time is within the second time range. .

[0149] For example, The range can be (130℃, 175℃), The range can be (15min, 30min).

[0150] Second temperature range Second time range Under stronger heat treatment conditions, higher thermal energy provides a stronger driving force for oxygen atoms to diffuse towards the center of the barrier, and longer heating time ensures that the diffusion process is fully carried out, thereby forming a more uniform and higher barrier layer, achieving a significant increase in the resistance value.

[0151] It is understood here that this application includes, but is not limited to, two-level graded control. In some other embodiments, multiple thresholds (such as a second threshold, a third threshold, etc.) can be set to divide the control mode into three or more levels (e.g., fine-tuning mode, medium-tuning mode, emphasis mode), with each level corresponding to a different combination of temperature range and time range, in order to achieve more refined resistance control and meet the accuracy and efficiency requirements of different application scenarios.

[0152] This application uses an adjustment ratio P (i.e., the percentage of the initial resistance value to be adjusted) instead of the resistance value. Using the absolute value as the criterion for grading allows this graded control strategy to be applied to Josephson junctions with different design resistance values. Under proportional graded thermal processing control, both fall into the same control mode (e.g., small-amplitude control), obtaining matched thermal processing parameters. However, in absolute value-based schemes, different absolute values ​​may be misjudged as different levels, leading to improper resistance control. Therefore, this application can eliminate the scaling effect caused by differences in design resistance values, eliminating the need to recalibrate the threshold for each quantum chip and improving the versatility of the process.

[0153] The graded heat treatment control employed in this application allows for fine-tuning under mild conditions during small-scale adjustments, avoiding the risk of over-adjustment due to excessive heat budget. During large-scale adjustments, enhanced conditions provide sufficient thermal driving force, ensuring that the resistance can be reliably adjusted to the target resistance value, thereby achieving high process accuracy and controllability throughout the entire control range.

[0154] Staged thermal control also ensures that the supplied thermal budget matches the adjustment ratio of actual needs: small-scale adjustments avoid applying excessive heat energy, preventing unnecessary thermal shock to the Josephson junction barrier layer or other structures of the quantum chip. Large-scale adjustments provide sufficient thermal budget, ensuring the control effect while maintaining controllable thermal stress through the liquid-phase homogenization properties of organic solvents. This precise matching of the thermal budget can further reduce the risk of quantum chip damage and improve manufacturing yield.

[0155] Optionally, the temperature controller 30 can be a PID controller (Proportional-Integral-Derivative).

[0156] For example, the heating surface of the hot plate 20 is spatially divided into multiple independent temperature control zones, including a central temperature control zone and an edge temperature control zone. Each temperature control zone is equipped with an independent heating element (such as a resistance wire or thin-film heater) and a corresponding temperature sensor (such as a thermocouple or platinum resistance thermometer). The PID controller receives real-time temperature information from each temperature control zone and independently calculates the control output for each temperature control zone.

[0157] For the edge temperature control zone, since its heat dissipation rate is significantly higher than that of the central temperature control zone (i.e., edge heat loss), the PID controller automatically identifies the temperature drop trend in this area. Under the proportional (P) term, the PID controller increases the heating power of the edge temperature control zone proportionally to the magnitude of the temperature deviation. Under the integral (I) term, the PID controller eliminates the long-term steady-state temperature error in the edge region. Under the derivative (D) term, the PID controller predicts the heat dissipation trend of the edge temperature control zone in advance based on the rate of temperature change and increases the heating power in advance before the temperature drops significantly, thereby achieving dynamic compensation.

[0158] As an example, during the heating process of the hot plate 20, in the initial stage of heating, the PID controller outputs maximum power to drive all temperature control zones to heat up rapidly. When the central temperature control zone approaches the preset temperature, the PID controller reduces its heating power to prevent overshoot. However, due to greater heat loss, the temperature of the edge temperature control zones remains below the set value. The PID controller maintains or even increases the heating power of the edge areas through proportional and integral actions, forming an asymmetric power output mode of "central stability and edge enhancement".

[0159] Optionally, the temperature variation range of the heating surface of the hot plate 20 is less than or equal to ±1℃.

[0160] Once the constant temperature phase begins, the PID controller monitors the temperature fluctuations in each zone in real time. When the PID controller detects a cooling trend in the edge area due to ambient airflow or operational disturbances, the derivative (D) term responds immediately, dynamically increasing the heating power of that temperature-controlled zone at the onset of cooling to suppress temperature fluctuations within ±1°C.

[0161] Through the above embodiments, this application, by setting a temperature controller, can independently control the heating temperature of the hot plate in zones, so that the temperature uniformity of the entire heating surface can reach ±1°C. This application can ensure that the heat transfer at the bottom of the water bath has highly uniform boundary conditions, providing a stable and uniform thermal environment for the preset organic solvent and the quantum chip immersed in the water bath.

[0162] Optionally, the preset organic solvent is an electronic-grade N-methylpyrrolidone solution. The purity of the electronic-grade N-methylpyrrolidone solution is greater than 99.9%.

[0163] For example, N-methylpyrrolidone is a polar aprotic solvent with a high boiling point (approximately 202°C), good thermal stability, excellent solubility, and chemical inertness to superconducting chip materials (such as aluminum, niobium, and alumina barrier layers). Its high purity of over 99.9% ensures that the preset organic solvent does not contain metal ions, particulate matter, or organic impurities that could potentially contaminate the surface of the quantum chip.

[0164] Finally, it should be noted that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions of the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for controlling the bit frequency of a superconducting quantum chip, characterized in that, include: The superconducting quantum chip is placed in a water bath container, which contains a pre-prepared organic solvent. The water bath container is placed on a hot plate, and the heating temperature and heating time of the hot plate are adjusted by a temperature controller electrically connected to the hot plate. The initial resistance of the Josephson junction on the superconducting quantum chip was measured in its initial state. Based on the initial resistance value and the target resistance value of the Josephson junction, the temperature controller is controlled to adjust the heating temperature and the heating time, so as to perform global heating and annealing of the Josephson junction by water bath through the thermal conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and controlling the bit frequency of the superconducting quantum chip.

2. The control method according to claim 1, characterized in that, The step of controlling the temperature controller to adjust the heating temperature and the heating time based on the initial resistance value and the target resistance value of the Josephson junction includes: The adjustment resistance value is determined based on the initial resistance value and the target resistance value; The adjustment ratio is determined based on the adjustment resistance value and the initial resistance value; When the adjustment ratio is less than the first threshold, the heating temperature of the hot plate is controlled to be within a first temperature range, and the heating time is within a first time range; When the adjustment ratio is not less than the first threshold, the heating temperature of the hot plate is controlled to be within a second temperature range, and the heating time is within a second time range.

3. The control method according to claim 1, characterized in that, The temperature controller is a PID controller.

4. The control method according to claim 1, characterized in that, The preset organic solvent is an electronic-grade N-methylpyrrolidone solution.

5. The control method according to claim 4, characterized in that, The purity of the electronic-grade N-methylpyrrolidone solution is greater than 99.9%.

6. A system for controlling the bit frequency of a superconducting quantum chip, characterized in that, include: A water bath container, pre-filled with a preset organic solvent, is used to hold the superconducting quantum chip; A hot plate, on which the water bath container is placed; A temperature controller, electrically connected to the hot plate, is used to adjust the heating temperature and heating time of the hot plate; The resistance measurement module is used to measure the initial resistance value of the Josephson junction on the superconducting quantum chip in its initial state. The central control module is electrically connected to the resistance measurement module and the temperature controller. Based on the initial resistance value and the target resistance value of the Josephson junction, the temperature controller is controlled to adjust the heating temperature and the heating time, so as to perform global heating and annealing of the Josephson junction by water bath method through the thermal conduction of the preset organic solvent, thereby controlling the resistance value of the Josephson junction and controlling the bit frequency of the superconducting quantum chip.

7. The control system according to claim 6, characterized in that, The central control module determines the adjustment resistance value based on the initial resistance value and the target resistance value; The central control module determines the adjustment ratio based on the adjustment resistance value and the initial resistance value; When the adjustment ratio is less than a first threshold, the central control module controls the heating temperature of the hot plate to a first temperature range and the heating time to a first time range. When the adjustment ratio is not less than the first threshold, the central control module controls the heating temperature of the hot plate to a second temperature range and the heating time to a second time range.

8. The control system according to claim 6, characterized in that, The temperature controller is a PID controller.

9. The control system according to claim 6, characterized in that, The preset organic solvent is an electronic-grade N-methylpyrrolidone solution.

10. The control system according to claim 9, characterized in that, The purity of the electronic-grade N-methylpyrrolidone solution is greater than 99.9%.

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