Method and device for measuring crosstalk of coaxial cable of dilution refrigerator, dilution refrigerator and superconducting quantum computing device

Abstract

The application provides a crosstalk measurement method and device for coaxial cables of a dilution refrigerator, the dilution refrigerator and a superconducting quantum computing device. The crosstalk measurement method comprises: loading a square wave pulse signal to one end of a reference coaxial cable group through an arbitrary wave generation component; collecting amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through a first port of an oscilloscope component; collecting ground crosstalk peak value information and spatial crosstalk peak value information of a crosstalk pulse signal at the other end of a crosstalk measurement coaxial cable group after amplification processing by a signal amplification component through a second port of the oscilloscope component; and determining a crosstalk ratio of a crosstalk type according to the amplitude information, the ground crosstalk peak value information and the spatial crosstalk peak value information; wherein the crosstalk type comprises a ground crosstalk type and a spatial crosstalk type, and the crosstalk ratio comprises a ground crosstalk ratio and a spatial crosstalk ratio.

Description

Technical Field

[0001] This invention relates to the technical field of dilution refrigerators, and more specifically, to a method and apparatus for measuring crosstalk in the coaxial cable of a dilution refrigerator, a dilution refrigerator, and a superconducting quantum computing device. Background Technology

[0002] Superconducting quantum computing is a physical realization of quantum computing that utilizes the quantum properties of superconducting materials. Experiments in superconducting quantum computing must be conducted at ultra-low temperatures (e.g., less than 20 mK). A dilution refrigerator is a key device providing ultra-low cooling for superconducting quantum computing. The dilution refrigerator has multiple stages of cold plates, which are a core component used to maintain and control the low-temperature environment. Superconducting quantum chips and various electronic devices (such as attenuators) are mounted on the cold plates, and signals (e.g., from DC to tens of GHz) are transmitted between the different stages of the cold plates via coaxial cables.

[0003] The inventors discovered that during signal transmission in coaxial cables, due to electromagnetic coupling, a change in current in one signal line can induce current or voltage in other signal lines, resulting in crosstalk. This crosstalk affects signal transmission quality, potentially leading to signal distortion, data loss, and instability in communication systems. For example, applying square wave pulse signals of different pulse widths to the coaxial cable of a dilution refrigerator can generate different types of crosstalk.

[0004] The type and proportion of crosstalk are of great significance to the study of crosstalk phenomena. Therefore, the inventors believe that determining the type and proportion of crosstalk between coaxial cables in a dilution refrigeration unit is a technical problem that needs to be solved.

[0005] 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

[0006] According to one aspect of the present invention, a method for measuring crosstalk in a coaxial cable of a dilution refrigerator is provided. The coaxial cable includes a reference coaxial cable group and a crosstalk measurement coaxial cable group. One end of the crosstalk measurement coaxial cable group is provided with a preset load. The crosstalk measurement method includes: loading a square wave pulse signal onto one end of the reference coaxial cable group through an arbitrary wave generator; acquiring amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through a first port of an oscilloscope component; acquiring ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group, amplified by a signal amplification component, through a second port of the oscilloscope component; determining the crosstalk ratio of the crosstalk type based on the amplitude information, ground crosstalk peak information, and spatial crosstalk peak information; wherein the crosstalk type includes ground crosstalk type and spatial crosstalk type, and the crosstalk ratio includes ground crosstalk ratio and spatial crosstalk ratio.

[0007] According to some embodiments of the present invention, determining the crosstalk ratio of crosstalk types based on amplitude information, ground crosstalk peak information, and spatial crosstalk peak information includes:

[0008] P 接地串扰 =20·lg(V) 地 / (N·V))

[0009] Among them, P 接地串扰 V represents the ground crosstalk ratio. 地 This represents the peak value of ground crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0010] According to some embodiments of the present invention, determining the crosstalk ratio of crosstalk types based on amplitude information, ground crosstalk peak information, and spatial crosstalk peak information includes:

[0011] P 空间串扰 =20·lg(V) 电磁 / (N·V))

[0012] Among them, P 空间串扰 V represents the spatial crosstalk ratio. 电磁 Here, N represents the peak value of spatial crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0013] According to some embodiments of the present invention, when performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group; or when performing the crosstalk measurement method at low temperature, the reference coaxial cable group includes at least a first coaxial cable group and a second coaxial cable group; wherein the first coaxial cable group and the second coaxial cable group are connected by a preset line.

[0014] According to one aspect of the present invention, a crosstalk measurement device for a coaxial cable of a dilution refrigerator is provided, comprising an arbitrary wave generation component, a signal amplification component, an oscilloscope component, and a signal processing component. The coaxial cable includes a reference coaxial cable group and a crosstalk measurement coaxial cable group, with a preset load at one end of the crosstalk measurement coaxial cable group. The arbitrary wave generation component loads a square wave pulse signal onto one end of the reference coaxial cable group; the signal amplification component amplifies the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group; the oscilloscope component acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through a first port; and acquires the ground crosstalk peak value information and spatial crosstalk peak value information of the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group, amplified by the signal amplification component, through a second port; the signal processing component determines the crosstalk ratio of the crosstalk type based on the amplitude information, the ground crosstalk peak value information, and the spatial crosstalk peak value information; wherein the crosstalk type includes ground crosstalk type and spatial crosstalk type, and the crosstalk ratio includes ground crosstalk ratio and spatial crosstalk ratio.

[0015] According to some embodiments of the present invention, the signal processing component calculates the ground crosstalk ratio according to the following formula:

[0016] P 接地串扰 =20·lg(V) 地 / (N·V))

[0017] Among them, P 接地串扰 V represents the ground crosstalk ratio. 地 This represents the peak value of ground crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0018] According to some embodiments of the present invention, the signal processing component calculates the spatial crosstalk ratio according to the following formula:

[0019] P 空间串扰 =20·lg(V) 电磁 / (N·V))

[0020] Among them, P 空间串扰 V represents the spatial crosstalk ratio. 电磁 Here, N represents the peak value of spatial crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0021] According to some embodiments of the present invention, when performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group; or when performing the crosstalk measurement method at low temperature, the reference coaxial cable group includes at least a first coaxial cable group and a second coaxial cable group; wherein the first coaxial cable group and the second coaxial cable group are connected by a preset line.

[0022] According to another aspect of the invention, a dilution refrigerator is also provided. This dilution refrigerator includes the crosstalk measurement device as described above.

[0023] According to another aspect of the present invention, a superconducting quantum computing device is also provided. This superconducting quantum computing device includes the dilution refrigerator as described above.

[0024] Beneficial effects

[0025] This invention loads a square wave pulse signal onto one end of a reference coaxial cable assembly using an arbitrary wave generator. The amplitude information of the square wave pulse signal at the other end of the reference coaxial cable assembly is acquired through the first port of an oscilloscope assembly. Furthermore, the ground crosstalk peak value and spatial crosstalk peak value of the crosstalk pulse signal at the other end of the coaxial cable assembly, amplified by a signal amplification component, are acquired through the second port of the oscilloscope assembly. Based on this amplitude information, ground crosstalk peak value, and spatial crosstalk peak value, the type and proportion of crosstalk between coaxial cables at room temperature can be determined using a calculation formula.

[0026] The crosstalk measurement method for coaxial cables provided by this invention allows for the measurement of the type of crosstalk in square wave pulse signals using a simple crosstalk measurement device. Furthermore, the crosstalk ratio can be calibrated for different types of crosstalk. This invention provides data support for crosstalk suppression in coaxial cables. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the crosstalk measurement method according to an embodiment of the present invention is shown;

[0029] Figure 2 This diagram illustrates yet another structural schematic of the crosstalk measurement method according to an embodiment of the present invention;

[0030] Figure 3 A flowchart illustrating the crosstalk measurement method according to an embodiment of the present invention is shown;

[0031] Figure 4 A schematic diagram of a square wave pulse signal according to an embodiment of the present invention is shown;

[0032] Figure 5 A schematic diagram of a crosstalk pulse signal according to an embodiment of the present invention is shown;

[0033] Figure 6 A schematic diagram of the crosstalk measurement device according to an embodiment of the present invention is shown.

[0034] Explanation of reference numerals in the attached figures:

[0035] Crosstalk measurement device 1; arbitrary wave generation component 10; signal amplification component 20; oscilloscope component 30; signal processing component 40. Detailed Implementation

[0036] 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 the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed 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.

[0037] 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.

[0038] 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.

[0039] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, rather than to describe a specific order.

[0040] The technical solutions of the present invention 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 the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] According to one aspect of the present invention, the present invention provides a method for measuring crosstalk of coaxial cables in a dilution refrigerator, for measuring the type and proportion of crosstalk between coaxial cables in room temperature and low temperature environments.

[0042] Figure 1 A schematic diagram of the crosstalk measurement method according to an embodiment of the present invention is shown; Figure 2 This diagram illustrates another structural schematic of the crosstalk measurement method according to an embodiment of the present invention.

[0043] According to an example embodiment, the dilution refrigeration machine provided by the present invention includes at least a first temperature layer, a second temperature layer, a third temperature layer, and a fourth temperature layer.

[0044] The dilution refrigeration unit may include five stages of cold plates, such as Figure 1 or Figure 2 The diagram shows a first, second, third, fourth, and fifth cold plate. Adjacent cold plates are separated by different temperature zones. Attenuation components, such as attenuators, can be installed on the first, second, and third temperature zones.

[0045] For example, the first cold plate can be a 50K cold plate, the second cold plate can be a 4K cold plate, the third cold plate can be a 600mK distillation layer cold plate, the fourth cold plate can be a 100mK cold plate, and the fifth cold plate can be a 10mK mixing chamber cold plate.

[0046] According to an example embodiment, the coaxial cable of the dilution refrigeration unit may include at least two sets of coaxial cable groups. It is understood here that the coaxial cable sequentially connecting the first cold plate, the second cold plate, the third cold plate, the fourth cold plate, and the fifth cold plate can be considered as one set of coaxial cable groups.

[0047] According to the example embodiment, the cold plates of each stage of the dilution refrigeration unit can be connected by coaxial cables. The two sets of coaxial cables may include a reference coaxial cable set S1 and a crosstalk measurement coaxial cable set S2.

[0048] For example, the reference coaxial cable group S1 can be used as a reference signal transmission channel, that is, the channel through which the actual signal is transmitted; the crosstalk measurement coaxial cable group S2 can be used as a crosstalk measurement signal transmission channel, that is, the signal measurement channel through which the crosstalk of the measurement coaxial cable transmission signal to the coaxial cable group is transmitted.

[0049] According to the example embodiment, the crosstalk measurement method provided by the present invention can be performed at room temperature or at low temperature. For example, the room temperature environment can be 300K, and the low temperature environment can be 10mK-20mK.

[0050] Optionally, when performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group.

[0051] For example, such as Figure 1As shown, at room temperature, the reference coaxial cable group S1 consists of a set of coaxial cables.

[0052] Optionally, when performing crosstalk measurement in a low-temperature environment, the reference coaxial cable group S1 includes at least a first coaxial cable group L1 and a second coaxial cable group L2. The first coaxial cable group L1 and the second coaxial cable group L2 are connected by a preset line.

[0053] For example, such as Figure 2 As shown, the reference coaxial cable group S1 consists of two coaxial cable groups. The first coaxial cable group L1 and the second coaxial cable group L2 are connected at the bottom of the fifth cold plate by a flexible coaxial cable.

[0054] With this configuration, the present invention can make the crosstalk measurement method provided by the present invention applicable to various temperature environments such as room temperature environment and low temperature environment by using different reference coaxial cable structure settings, and is not affected by changes in environmental factors.

[0055] According to the example embodiment, such as Figure 1 or Figure 2 As shown, one end of the reference coaxial cable assembly S1 is connected to an arbitrary wave generator component. Exemplarily, this arbitrary wave generator component can be an arbitrary wave generator. The other end of the reference coaxial cable assembly S1 is connected to an oscilloscope component, and the other end of the reference coaxial cable assembly S1 is connected to the first port 1 of the oscilloscope component. Exemplarily, this oscilloscope component can be an oscilloscope.

[0056] like Figure 1 or Figure 2 As shown, a preset load is provided at one end of the crosstalk measurement coaxial cable group S2, so that the line containing the crosstalk measurement coaxial cable group S2 can be simulated as a signal transmission line under impedance matching corresponding to the preset load. For example, the preset load can be a 50Ω load.

[0057] The other end of the coaxial cable assembly S2 for crosstalk measurement is connected in sequence to a signal amplification component and an oscilloscope component. The crosstalk pulse signal output from the other end of the coaxial cable assembly S2 is amplified by the signal amplification component and then connected to the second port 2 of the oscilloscope component. For example, the signal amplification component can be a low-frequency signal amplifier.

[0058] Figure 3 A flowchart illustrating a crosstalk measurement method according to an embodiment of the present invention is shown. Figure 4 A schematic diagram of a square wave pulse signal according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of a crosstalk pulse signal according to an embodiment of the present invention is shown.

[0059] like Figure 3As shown, the crosstalk measurement method may include steps S100-S400. Exemplarily, the crosstalk measurement method may be performed by a crosstalk measurement device with computing capabilities.

[0060] In step S100, the crosstalk measurement device loads a square wave pulse signal onto one end of the reference coaxial cable group through the arbitrary wave generator component.

[0061] In step S200, the crosstalk measurement device acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through the first port of the oscilloscope component.

[0062] For example, the crosstalk measurement device can, according to user requirements, load a square wave pulse signal generated by an arbitrary wave generator onto one end of a reference coaxial cable assembly. The crosstalk measurement device then acquires the amplitude information V and pulse width information T of the square wave pulse signal through the first port 1 of the oscilloscope assembly (e.g., ...). Figure 4 (As shown).

[0063] In step S300, the crosstalk measurement device acquires the ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal amplified by the signal amplification component at the other end of the crosstalk measurement coaxial cable group through the second port of the oscilloscope component.

[0064] For example, such as Figure 1 or Figure 2 As shown, the other end of the crosstalk measurement coaxial cable group S2 is connected to a signal amplification component (such as a low-frequency signal amplifier). The crosstalk pulse signal in the crosstalk measurement coaxial cable group S2 is amplified N times by the signal amplification component and then connected to the second port 2 of the oscilloscope component.

[0065] like Figure 5 As shown, the ground crosstalk peak information can be the peak value V of the signal portion that enters through the ground loop, as acquired by the oscilloscope component. 地 Spatial crosstalk peak information can be the peak value V of the overcharge signal portion caused by spatial crosstalk, which is acquired by the oscilloscope components. 电磁 .

[0066] In step S400, the crosstalk measurement device determines the crosstalk ratio of each crosstalk type based on the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information. The crosstalk types include ground crosstalk and spatial crosstalk, and the crosstalk ratio includes the ground crosstalk ratio and the spatial crosstalk ratio.

[0067] For example, the crosstalk types of coaxial cables in a dilution chiller include ground crosstalk and spatial crosstalk, and the corresponding crosstalk ratio can be determined by the signal information collected by an oscilloscope.

[0068] Optionally, in step S400, the formula for calculating the ground crosstalk ratio can be:

[0069] P 接地串扰 =20·lg(V) 地 / (N·V))

[0070] Among them, P 接地串扰 This represents the ground crosstalk ratio, expressed in dB, V. 地 This represents the peak value of ground crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0071] Optionally, in step S400, the formula for calculating the spatial crosstalk ratio can be:

[0072] P 空间串扰 =20·lg(V) 电磁 / (N·V))

[0073] Among them, P 空间串扰 This represents the spatial crosstalk ratio, expressed in dB, V. 电磁 Here, N represents the peak value of spatial crosstalk, N represents the amplification factor of the signal amplification component, and V represents the amplitude information.

[0074] It is understood that since attenuators with different attenuation values ​​can be used between different cold plates, and the distribution of attenuators can also affect crosstalk, quantitative comparison of crosstalk can be performed by replacing different attenuators. Furthermore, based on the same principle as the crosstalk measurement method of this invention, the type and proportion of crosstalk in coaxial cables at different distances from the signal transmission channel can also be measured, and this invention does not limit this.

[0075] Through the above embodiments, the present invention loads a square wave pulse signal onto one end of a reference coaxial cable group using an arbitrary wave generator, acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through the first port of the oscilloscope, and acquires the ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal at the other end of the coaxial cable group after amplification by the signal amplification component through the second port of the oscilloscope. Based on the amplitude information, ground crosstalk peak information, and spatial crosstalk peak information, the crosstalk type and crosstalk ratio between coaxial cables under room temperature environment can be determined by calculation formula.

[0076] The crosstalk measurement method for coaxial cables provided by this invention allows for the measurement of the type of crosstalk in square wave pulse signals using a simple crosstalk measurement device. Furthermore, the crosstalk ratio can be calibrated for different types of crosstalk. This invention provides data support for crosstalk suppression in coaxial cables.

[0077] According to another aspect of the present invention, the present invention provides a crosstalk measuring device for coaxial cables of a dilution refrigerator, for measuring the type and proportion of crosstalk between coaxial cables under room temperature and low temperature environments.

[0078] Figure 6 A schematic diagram of a crosstalk measurement device according to an embodiment of the present invention is shown. Figure 6 As shown, the crosstalk measurement device 1 includes an arbitrary wave generation component 10, a signal amplification component 20, an oscilloscope component 30, and a signal processing component 40.

[0079] According to an example embodiment, the coaxial cable of the dilution refrigerator may include at least two sets of coaxial cable groups. The cold plates of each stage of the dilution refrigerator can be connected via coaxial cables, and these two sets of coaxial cable groups may include a reference coaxial cable group S1 and a crosstalk measurement coaxial cable group S2.

[0080] For example, the reference coaxial cable group S1 can be used as a reference signal transmission channel, that is, the channel through which the actual signal is transmitted; the crosstalk measurement coaxial cable group S2 can be used as a crosstalk measurement signal transmission channel, that is, the signal measurement channel through which the crosstalk of the measurement coaxial cable transmission signal to the coaxial cable group is transmitted.

[0081] According to the example embodiment, the crosstalk measurement device provided by the present invention can perform measurements at room temperature or at low temperature. For example, the room temperature environment can be 300K, and the low temperature environment can be 10mK-20mK.

[0082] Optionally, when performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group.

[0083] For example, such as Figure 1 As shown, at room temperature, the reference coaxial cable group S1 consists of a set of coaxial cables.

[0084] Optionally, when performing crosstalk measurement in a low-temperature environment, the reference coaxial cable group S1 includes at least a first coaxial cable group L1 and a second coaxial cable group L2. The first coaxial cable group L1 and the second coaxial cable group L2 are connected by a preset line.

[0085] For example, such as Figure 2 As shown, the reference coaxial cable group S1 consists of two coaxial cable groups. The first coaxial cable group L1 and the second coaxial cable group L2 are connected at the bottom of the fifth cold plate by a flexible coaxial cable.

[0086] With this configuration, the present invention can make the crosstalk measurement method provided by the present invention applicable to various temperature environments such as room temperature environment and low temperature environment by using different reference coaxial cable structure settings, and is not affected by changes in environmental factors.

[0087] According to the example embodiment, such as Figure 1 or Figure 2As shown, one end of the reference coaxial cable assembly S1 is connected to an arbitrary wave generator component 10. Exemplarily, the arbitrary wave generator component 10 can be an arbitrary wave generator. The other end of the reference coaxial cable assembly S1 is connected to an oscilloscope component 30, and the other end of the reference coaxial cable assembly S1 is connected to the first port 1 of the oscilloscope component 30. Exemplarily, the oscilloscope component 30 can be an oscilloscope.

[0088] like Figure 1 or Figure 2 As shown, a preset load is provided at one end of the crosstalk measurement coaxial cable group S2, so that the line containing the crosstalk measurement coaxial cable group S2 can be simulated as a signal transmission line under impedance matching corresponding to the preset load. For example, the preset load can be a 50Ω load.

[0089] The other end of the crosstalk measurement coaxial cable assembly S2 is connected in sequence to the signal amplification component 20 and the oscilloscope component 30. The crosstalk pulse signal output from the other end of the crosstalk measurement coaxial cable assembly S2 is amplified by the signal amplification component 20 and then connected to the second port 2 of the oscilloscope component 30. For example, the signal amplification component 20 can be a low-frequency signal amplifier.

[0090] According to an example embodiment, the arbitrary wave generating component 10 loads a square wave pulse signal onto one end of a reference coaxial cable assembly.

[0091] The oscilloscope assembly 30 acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable assembly through the first port.

[0092] For example, the arbitrary wave generator 10 can, according to user requirements, load the square wave pulse signal generated by the arbitrary wave generator 10 onto one end of the reference coaxial cable assembly. Then, the oscilloscope assembly 30 acquires the amplitude information V and pulse width information T (e.g., ...) of the square wave pulse signal through the first port 1. Figure 4 (As shown).

[0093] The oscilloscope component 30 acquires the ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal amplified and processed by the signal amplification component 20 at the other end of the crosstalk measurement coaxial cable group through the second port.

[0094] For example, such as Figure 1 or Figure 2 As shown, the other end of the crosstalk measurement coaxial cable group S2 is connected to the signal amplification component 20 (such as a low-frequency signal amplifier). The crosstalk pulse signal in the crosstalk measurement coaxial cable group S2 is amplified by N times by the low-frequency signal amplifier and then connected to the second port 2 of the oscilloscope component 30.

[0095] like Figure 5 As shown, the ground crosstalk peak information can be the peak value V of the signal portion that enters through the ground loop, as acquired by the oscilloscope.地 Spatial crosstalk peak information can be the peak value V of the overcharged signal portion caused by spatial crosstalk. 电磁 .

[0096] The signal processing component 40 determines the crosstalk ratio of each crosstalk type based on the amplitude information, the peak ground crosstalk information, and the peak spatial crosstalk information. Crosstalk types include ground crosstalk and spatial crosstalk, and the crosstalk ratio includes both ground crosstalk ratio and spatial crosstalk ratio.

[0097] For example, the crosstalk types of the coaxial cable of the dilution refrigerator include ground crosstalk and spatial crosstalk, and the signal processing component 40 can determine the corresponding crosstalk ratio through the signal information collected by the oscilloscope component.

[0098] Alternatively, the formula for calculating the ground crosstalk ratio can be:

[0099] P 接地串扰 =20·lg(V) 地 / (N·V))

[0100] Among them, P 接地串扰 This represents the ground crosstalk ratio, expressed in dB, V. 地 The value represents the peak ground crosstalk information, N represents the amplification factor of the signal amplification component 20, and V represents the amplitude information.

[0101] Alternatively, the formula for calculating the spatial crosstalk ratio can be:

[0102] P 空间串扰 =20·lg(V) 电磁 / (N·V))

[0103] Among them, P 空间串扰 This represents the spatial crosstalk ratio, expressed in dB, V. 电磁 N represents the peak value of spatial crosstalk, N represents the amplification factor of the signal amplification component 20, and V represents the amplitude information.

[0104] It is understood that since attenuators with different attenuation values ​​can be used between different cold plates, and the distribution of attenuators can also affect crosstalk, quantitative comparison of crosstalk can be performed by replacing different attenuators. Furthermore, based on the same principle as the crosstalk measurement method of this invention, the crosstalk measurement device can also measure the type and proportion of crosstalk in coaxial cables at different distances from the signal transmission channel; this invention does not limit this.

[0105] Through the above embodiments, the present invention loads a square wave pulse signal onto one end of a reference coaxial cable group using an arbitrary wave generator, acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through the first port of the oscilloscope, and acquires the ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal at the other end of the coaxial cable group after amplification by the signal amplification component through the second port of the oscilloscope. Based on the amplitude information, ground crosstalk peak information, and spatial crosstalk peak information, the crosstalk type and crosstalk ratio between coaxial cables under room temperature environment can be determined by calculation formula.

[0106] The crosstalk measurement method for coaxial cables provided by this invention allows for the measurement of the type of crosstalk in square wave pulse signals using a simple crosstalk measurement device. Furthermore, the crosstalk ratio can be calibrated for different types of crosstalk. This invention provides data support for crosstalk suppression in coaxial cables.

[0107] According to another aspect of the invention, a dilution refrigerator is also provided. This dilution refrigerator includes the crosstalk measurement device as described above.

[0108] According to another aspect of the present invention, a superconducting quantum computing device is also provided. This superconducting quantum computing device includes the dilution refrigerator as described above.

[0109] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention 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 the present invention should be included within the protection scope of the present invention.

Claims

1. A method for measuring crosstalk in a coaxial cable of a dilution refrigeration unit, characterized in that, The coaxial cable includes a reference coaxial cable group and a crosstalk measurement coaxial cable group. One end of the crosstalk measurement coaxial cable group is provided with a preset load. The crosstalk measurement method includes: A square wave pulse signal is applied to one end of the reference coaxial cable assembly by an arbitrary wave generator component. The amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group is acquired through the first port of the oscilloscope component. The ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal amplified by the signal amplification component are acquired through the second port of the oscilloscope component at the other end of the crosstalk measurement coaxial cable group. Based on the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information, the crosstalk ratio of the crosstalk type is determined; The crosstalk types include ground crosstalk and spatial crosstalk, and the crosstalk ratios include ground crosstalk ratios and spatial crosstalk ratios. The step of determining the crosstalk ratio of the crosstalk type based on the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information includes: P 接地串扰 =20·lg(V 地 / (N·V)) Among them, P 接地串扰 V is the ground crosstalk ratio. 地 The ground crosstalk peak value is N, the amplification factor of the signal amplification component is N, and the amplitude information is V. The step of determining the crosstalk ratio of the crosstalk type based on the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information includes: P 空间串扰 =20·lg(V 电磁 / (N·V)) Among them, P 空间串扰 V represents the spatial crosstalk ratio. 电磁 The spatial crosstalk peak information is given, N is the amplification factor of the signal amplification component, and V is the amplitude information.

2. The crosstalk measurement method according to claim 1, characterized in that, When performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group; or When performing the crosstalk measurement method in a low-temperature environment, the reference coaxial cable group includes at least a first coaxial cable group and a second coaxial cable group; wherein the first coaxial cable group and the second coaxial cable group are connected by a preset line.

3. A crosstalk measuring device for coaxial cables in a dilution refrigeration unit, characterized in that, The crosstalk measurement device is used to perform the crosstalk measurement method as described in any one of claims 1-2, the coaxial cable includes a reference coaxial cable group and a crosstalk measurement coaxial cable group, one end of the crosstalk measurement coaxial cable group is provided with a preset load, and the crosstalk measurement device includes: An arbitrary wave generator component applies a square wave pulse signal to one end of the reference coaxial cable assembly; The signal amplification component amplifies the crosstalk pulse signal at the other end of the coaxial cable assembly used for crosstalk measurement. The oscilloscope assembly acquires the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through the first port; and acquires the ground crosstalk peak information and spatial crosstalk peak information of the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group after amplification by the signal amplification assembly through the second port. The signal processing component determines the crosstalk ratio of the crosstalk type based on the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information; wherein the crosstalk type includes ground crosstalk type and spatial crosstalk type, and the crosstalk ratio includes ground crosstalk ratio and spatial crosstalk ratio; The signal processing component calculates the ground crosstalk ratio according to the following formula: P 接地串扰 =20·lg(V 地 / (N·V)) Among them, P 接地串扰 V is the ground crosstalk ratio. 地 The ground crosstalk peak value is N, the amplification factor of the signal amplification component is N, and the amplitude information is V. The signal processing component calculates the spatial crosstalk ratio according to the following formula: P 空间串扰 =20·lg(V 电磁 / (N·V)) Among them, P 空间串扰 V represents the spatial crosstalk ratio. 电磁 The spatial crosstalk peak information is given, N is the amplification factor of the signal amplification component, and V is the amplitude information.

4. The crosstalk measuring device according to claim 3, characterized in that, When performing the crosstalk measurement method at room temperature, the reference coaxial cable group includes at least one coaxial cable group; or When performing the crosstalk measurement method in a low-temperature environment, the reference coaxial cable group includes at least a first coaxial cable group and a second coaxial cable group; wherein the first coaxial cable group and the second coaxial cable group are connected by a preset line.

5. A dilution refrigeration machine, characterized in that, Includes the crosstalk measurement device as described in any one of claims 3-4.

6. A superconducting quantum computing device, characterized in that, Includes the dilution refrigeration unit as described in claim 5.

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