Crosstalk measurement method and device for coaxial cable of dilution refrigerator, dilution refrigerator and superconducting quantum computing equipment

Abstract

The invention provides a crosstalk measurement method and device for a coaxial cable of a dilution refrigerator, the dilution refrigerator and superconducting quantum computing equipment. The crosstalk measurement method comprises the following steps: loading a square wave pulse signal to one end of a reference coaxial cable group through an arbitrary wave generation assembly; acquiring amplitude information of a square wave pulse signal at the other end of the reference coaxial cable group through a first port of the oscillographic assembly; acquiring grounding crosstalk peak information and space 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 a second port of the oscillographic component; determining a crosstalk proportion of the crosstalk type according to the amplitude information, the grounding crosstalk peak information and the space crosstalk peak information; wherein the crosstalk type comprises a grounding crosstalk type and a space crosstalk type, and the crosstalk proportion comprises a grounding crosstalk proportion and a space crosstalk proportion.

Description

Technical Field

[0001] The present invention relates to the technical field of dilution refrigerators, and in particular to a method and device for measuring crosstalk of a coaxial cable of a dilution refrigerator, a dilution refrigerator, and a superconducting quantum computing device. Background Art

[0002] Superconducting quantum computing is a physical implementation method of quantum computing that uses the quantum properties of superconducting materials. Experiments in superconducting quantum computing must be conducted at ultra-low temperatures (such as less than 20mK). Dilution refrigerators are key equipment for providing ultra-low cooling for superconducting quantum computing. The dilution refrigerator is equipped with multiple stages of cold plates, which are one of the core components of the dilution refrigerator and are used to maintain a low-temperature environment and control the temperature. Superconducting quantum chips and various electronic devices (such as attenuators, etc.) are arranged on the cold plates, and signals (such as DC to more than ten GHz) are transmitted between the cold plates at each level through coaxial cables.

[0003] The inventors have found that during signal transmission in a coaxial cable, due to the electromagnetic coupling effect, the current change of one signal line will induce current or voltage in other signal lines, thereby forming a crosstalk phenomenon. This crosstalk phenomenon will affect the transmission quality of the signal, which may lead to problems such as signal distortion, data loss and instability of the communication system. For example, when square wave pulse signals with different pulse widths are applied to the coaxial cable of a dilution refrigerator, different types of crosstalk will be formed.

[0004] The type and ratio of crosstalk are of great significance to the study of crosstalk phenomenon. Therefore, the inventor believes that how to determine the type and ratio of crosstalk between coaxial cables in a dilution refrigerator is a technical problem that needs to be solved.

[0005] The contents of the background technology section are merely the technologies known to the public and do not necessarily represent the existing technologies in the field. Summary of the invention

[0006] According to one aspect of the present invention, the present invention provides a crosstalk measurement method for a coaxial cable of a dilution refrigerator, the coaxial cable comprising a reference coaxial cable group and a crosstalk measurement coaxial cable group, one end of the crosstalk measurement coaxial cable group being provided with a preset load, the crosstalk measurement method comprising: loading a square wave pulse signal to one end of the reference coaxial cable group through an arbitrary wave generating 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 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 a signal amplification component through a second port of the oscilloscope component; determining a crosstalk ratio of a crosstalk type according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak 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.

[0007] According to some embodiments of the present invention, determining the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information, and the 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 is the ground crosstalk ratio, V 地 is the ground crosstalk peak information, N is the amplification factor of the signal amplification component, and V is the amplitude information.

[0010] According to some embodiments of the present invention, determining the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information, and the 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 is the spatial crosstalk ratio, V 电磁 is the spatial crosstalk peak information, N is the amplification factor of the signal amplification component, and V is the amplitude information.

[0013] According to some embodiments of the present invention, when the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group; or when the crosstalk measurement method is performed 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 via a preset line.

[0014] According to one aspect of the present invention, the present invention provides a crosstalk measurement device for a coaxial cable of a dilution refrigerator, comprising an arbitrary wave generating component, a signal amplifying component, an oscilloscope component and a signal processing component. The coaxial cable comprises a reference coaxial cable group and a crosstalk measuring coaxial cable group, and a preset load is arranged at one end of the crosstalk measuring coaxial cable group. The arbitrary wave generating component loads a square wave pulse signal to one end of the reference coaxial cable group; the signal amplifying component amplifies the crosstalk pulse signal at the other end of the crosstalk measuring coaxial cable group; the oscilloscope component collects the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through a first port; the ground crosstalk peak information and the spatial crosstalk peak information of the crosstalk pulse signal at the other end of the crosstalk measuring coaxial cable group after amplification and processing by the signal amplifying component are collected through a second port; the signal processing component determines the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information; wherein the crosstalk type comprises the ground crosstalk type and the spatial crosstalk type, and the crosstalk ratio comprises the ground crosstalk ratio and the 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 is the ground crosstalk ratio, V 地 is the ground crosstalk peak information, N is the amplification factor of the signal amplification component, and V is 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 is the spatial crosstalk ratio, V 电磁 is the spatial crosstalk peak information, N is the amplification factor of the signal amplification component, and V is the amplitude information.

[0021] According to some embodiments of the present invention, when the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group; or when the crosstalk measurement method is performed 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 via a preset line.

[0022] According to another aspect of the present invention, the present invention further provides a dilution refrigerator, which comprises the crosstalk measurement device as described above.

[0023] According to another aspect of the present invention, the present invention further provides a superconducting quantum computing device, which includes the dilution refrigerator as described above.

[0024] Beneficial Effects

[0025] The present invention loads a square wave pulse signal to one end of a reference coaxial cable group through an arbitrary wave generating component, collects 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, and collects 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 a signal amplification component through a second port of the oscilloscope component. The crosstalk type and crosstalk ratio between coaxial cables in a room temperature environment can be determined according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information through a calculation formula.

[0026] The crosstalk measurement method of the coaxial cable provided by the present invention can measure the type of square wave pulse signal crosstalk through a simple crosstalk measurement device, and can calibrate the crosstalk ratio for different types of crosstalk. The present invention can provide data support for crosstalk suppression for the crosstalk phenomenon of the coaxial cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0029] Figure 2 Another structural schematic diagram showing the crosstalk measurement method according to an embodiment of the present invention;

[0030] Figure 3 A schematic diagram showing a flow chart of a crosstalk measurement method according to an embodiment of the present invention;

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

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

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

[0034] Description of reference numerals:

[0035] Crosstalk measuring device 1; arbitrary wave generating component 10; signal amplifying component 20; oscilloscope component 30; signal processing component 40. DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0037] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices, etc. may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0038] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

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

[0040] The technical solution of the present invention is described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0041] According to one aspect of the present invention, a method for measuring crosstalk of coaxial cables of a dilution refrigerator is provided, which is used to measure the crosstalk type and crosstalk ratio between coaxial cables in room temperature environment and low temperature environment.

[0042] Figure 1 A schematic diagram showing a structure of a crosstalk measurement method according to an embodiment of the present invention; Figure 2 Another structural schematic diagram of the crosstalk measurement method according to an embodiment of the present invention is shown.

[0043] According to an exemplary embodiment, the dilution refrigerator 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 refrigerator may include five cold plates, such as Figure 1 or Figure 2 The first cold plate, the second cold plate, the third cold plate, the fourth cold plate and the fifth cold plate are shown. The first cold plate, the second cold plate, the third cold plate, the fourth cold plate and the fifth cold plate are adjacent to each other and have different temperature layers. The first temperature layer, the second temperature layer and the third temperature layer may be provided with an attenuation component, such as an attenuator.

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

[0046] According to example embodiments, the coaxial cables of the dilution refrigerator may include at least two coaxial cable groups. It is understood that the coaxial cables sequentially connecting the first cold plate, the second cold plate, the third cold plate, the fourth cold plate and the fifth cold plate may be regarded as one coaxial cable group.

[0047] According to an example embodiment, the cold plates of each stage of the dilution refrigerator may be connected by coaxial cables, and the two groups of coaxial cables may include a reference coaxial cable group S1 and a crosstalk measurement coaxial cable group S2.

[0048] Exemplarily, the reference coaxial cable group S1 can be used as a reference signal transmission channel, that is, a channel for transmitting actual signals; the crosstalk measurement coaxial cable group S2 can be used as a crosstalk measurement signal transmission channel, that is, a signal measurement channel for measuring the crosstalk of the coaxial cable transmission signal to the group of coaxial cable groups.

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

[0050] Optionally, when the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group.

[0051] For example, Figure 1As shown, under room temperature environment, the reference coaxial cable set S1 is composed of a set of coaxial cable sets.

[0052] Optionally, when the crosstalk measurement method is performed 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 via a preset line.

[0053] For example, Figure 2 As shown, the reference coaxial cable group S1 is composed of two coaxial cable groups, and the first coaxial cable group L1 and the second coaxial cable group L2 are connected at the bottom end of the fifth cold plate through a soft coaxial cable.

[0054] In this way, the present invention can use different reference coaxial cable structures to make the crosstalk measurement method provided by the present invention applicable to various temperature environments such as room temperature and low temperature environments, and will not be affected by changes in environmental factors.

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

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

[0057] The other end of the crosstalk measurement coaxial cable set S2 is connected to the signal amplifier component and the oscilloscope component in sequence. The crosstalk pulse signal outputted from the other end of the crosstalk measurement coaxial cable set S2 is amplified by the signal amplifier component and then connected to the second port 2 of the oscilloscope component. Exemplarily, the signal amplifier component may be a low-frequency signal amplifier.

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

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

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

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

[0062] For example, the crosstalk measurement device can load the square wave pulse signal generated by the arbitrary wave generating component to one end of the reference coaxial cable group according to user needs. Then the crosstalk measurement device collects the amplitude information V and pulse width information T of the square wave pulse signal through the first port 1 of the oscilloscope component (such as Figure 4 shown).

[0063] In step S300, the crosstalk measurement device collects 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 being amplified by the signal amplification component through the second port of the oscilloscope component.

[0064] For example, 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), and 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 part that is collected by the oscilloscope component and is inserted through the ground loop. 地 ; The spatial crosstalk peak information can be the peak value V of the overcharge signal part caused by the spatial crosstalk collected by the oscilloscope component 电磁 .

[0066] In step S400, the crosstalk measurement device determines the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information. The crosstalk type includes the ground crosstalk type and the spatial crosstalk type, and the crosstalk ratio includes the ground crosstalk ratio and the spatial crosstalk ratio.

[0067] For example, the crosstalk types of the coaxial cable of the dilution refrigerator include ground crosstalk type and space crosstalk type, and the corresponding crosstalk ratio can be determined through the signal information collected by the oscilloscope component.

[0068] Optionally, in step S400, the calculation formula of the ground crosstalk ratio may be:

[0069] P 接地串扰 =20·lg(V 地 / (N·V))

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

[0071] Optionally, in step S400, the calculation formula of the spatial crosstalk ratio may be:

[0072] P 空间串扰 =20·lg(V 电磁 / (N·V))

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

[0074] It can be understood here that since attenuators with different attenuation values ​​can be used between different cold plates, the distribution of attenuators can also affect the crosstalk, so quantitative comparison of crosstalk can be performed by replacing different attenuators. In addition, based on the same principle as the crosstalk measurement method of the present invention, the crosstalk type and crosstalk ratio of coaxial cables with different distances from the signal transmission channel can also be measured, and the present invention is not limited to this.

[0075] Through the above embodiments, the present invention loads a square wave pulse signal to one end of a reference coaxial cable group through an arbitrary wave generating component, collects 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, and collects the ground crosstalk peak information and the 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 component through the second port of the oscilloscope component. The crosstalk type and crosstalk ratio between the coaxial cables at room temperature can be determined according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information through a calculation formula.

[0076] The crosstalk measurement method of the coaxial cable provided by the present invention can measure the type of square wave pulse signal crosstalk through a simple crosstalk measurement device, and can calibrate the crosstalk ratio for different types of crosstalk. The present invention can provide data support for crosstalk suppression for the crosstalk phenomenon of the coaxial cable.

[0077] According to another aspect of the present invention, the present invention provides a crosstalk measurement device for coaxial cables of a dilution refrigerator, which is used to measure the crosstalk type and crosstalk ratio between coaxial cables in room temperature environment and low temperature environment.

[0078] Figure 6 FIG. 2 is a schematic diagram showing a structure of a crosstalk measurement device according to an embodiment of the present invention. Figure 6 As shown, the crosstalk measurement device 1 includes an arbitrary wave generating component 10 , a signal amplifying component 20 , an oscilloscope component 30 and a signal processing component 40 .

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

[0080] Exemplarily, the reference coaxial cable group S1 can be used as a reference signal transmission channel, that is, a channel for transmitting actual signals; the crosstalk measurement coaxial cable group S2 can be used as a crosstalk measurement signal transmission channel, that is, a signal measurement channel for measuring the crosstalk of the coaxial cable transmission signal to the group of coaxial cable groups.

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

[0082] Optionally, when the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group.

[0083] For example, Figure 1 As shown, under room temperature environment, the reference coaxial cable set S1 is composed of a set of coaxial cable sets.

[0084] Optionally, when the crosstalk measurement method is performed 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 via a preset line.

[0085] For example, Figure 2 As shown, the reference coaxial cable group S1 is composed of two coaxial cable groups, and the first coaxial cable group L1 and the second coaxial cable group L2 are connected at the bottom end of the fifth cold plate through a soft coaxial cable.

[0086] In this way, the present invention can use different reference coaxial cable structures to make the crosstalk measurement method provided by the present invention applicable to various temperature environments such as room temperature and low temperature environments, and will not be affected by changes in environmental factors.

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

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

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

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

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

[0092] For example, the arbitrary wave generating component 10 can load the square wave pulse signal generated by the arbitrary wave generating component 10 to one end of the reference coaxial cable group according to user needs. Then the oscilloscope component 30 collects the amplitude information V and pulse width information T of the square wave pulse signal through the first port 1 (such as Figure 4 shown).

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

[0094] For example, 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). After the crosstalk pulse signal in the crosstalk measurement coaxial cable group S2 is amplified N times by the low-frequency signal amplifier, it is connected to the second port 2 of the oscilloscope component 30.

[0095] like Figure 5 As shown in FIG. 1 , the ground crosstalk peak information can be the peak value V of the signal part that is inserted through the ground loop and collected by the oscilloscope.地 ; The spatial crosstalk peak information can be the peak value V of the overcharge signal part caused by the spatial crosstalk 电磁 .

[0096] The signal processing component 40 determines the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information. The crosstalk type includes the ground crosstalk type and the spatial crosstalk type, and the crosstalk ratio includes the ground crosstalk ratio and the spatial crosstalk ratio.

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

[0098] Optionally, a calculation formula for the ground crosstalk ratio may be:

[0099] P 接地串扰 =20·lg(V 地 / (N·V))

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

[0101] Optionally, the calculation formula of the spatial crosstalk ratio may be:

[0102] P 空间串扰 =20·lg(V 电磁 / (N·V))

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

[0104] It can be understood here that since attenuators with different attenuation values ​​can be used between different cold plates, the distribution of attenuators can also affect the crosstalk, so quantitative comparison of crosstalk can be performed by replacing different attenuators. In addition, based on the same principle as the crosstalk measurement method of the present invention, the crosstalk measurement device can also measure the crosstalk type and crosstalk ratio of coaxial cables at different distances from the signal transmission channel, and the present invention is not limited to this.

[0105] Through the above embodiments, the present invention loads a square wave pulse signal to one end of a reference coaxial cable group through an arbitrary wave generating component, collects 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, and collects the ground crosstalk peak information and the 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 component through the second port of the oscilloscope component. The crosstalk type and crosstalk ratio between the coaxial cables at room temperature can be determined according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information through a calculation formula.

[0106] The crosstalk measurement method of the coaxial cable provided by the present invention can measure the type of square wave pulse signal crosstalk through a simple crosstalk measurement device, and can calibrate the crosstalk ratio for different types of crosstalk. The present invention can provide data support for crosstalk suppression for the crosstalk phenomenon of the coaxial cable.

[0107] According to another aspect of the present invention, the present invention further provides a dilution refrigerator, which comprises the crosstalk measurement device as described above.

[0108] According to another aspect of the present invention, the present invention further provides a superconducting quantum computing device, which includes the dilution refrigerator as described above.

[0109] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions of the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring crosstalk of a coaxial cable of a dilution refrigerator, characterized in that: The coaxial cable comprises 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 method comprises: Loading a square wave pulse signal to one end of the reference coaxial cable group through an arbitrary wave generating component; Collecting 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; Collecting the ground crosstalk peak information and the spatial crosstalk peak information of the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group after being amplified by the signal amplification component through the second port of the oscilloscope component; Determining a crosstalk ratio of a crosstalk type according to the amplitude information, the ground crosstalk peak information, and the spatial crosstalk peak information; The crosstalk types include a ground crosstalk type and a spatial crosstalk type, and the crosstalk ratio includes a ground crosstalk ratio and a spatial crosstalk ratio.

2. The crosstalk measurement method according to claim 1, characterized in that: Determining the crosstalk ratio of the crosstalk type according to 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 is the ground crosstalk ratio, V 地 is the ground crosstalk peak information, N is the amplification factor of the signal amplifying component, and V is the amplitude information.

3. The crosstalk measurement method according to claim 1, characterized in that: Determining the crosstalk ratio of the crosstalk type according to 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 is the spatial crosstalk ratio, V 电磁 is the spatial crosstalk peak information, N is the amplification factor of the signal amplifying component, and V is the amplitude information.

4. The crosstalk measurement method according to claim 1, characterized in that: When the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group; or When the crosstalk measurement method is performed 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 via a preset line.

5. A crosstalk measurement device for a coaxial cable of a dilution refrigerator, characterized in that: The crosstalk measurement device is used to perform the crosstalk measurement method according to any one of claims 1 to 4, the coaxial cable comprises 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 comprises: An arbitrary wave generating component, which loads a square wave pulse signal to one end of the reference coaxial cable group; A signal amplifying component, amplifying the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group; The oscilloscope component collects the amplitude information of the square wave pulse signal at the other end of the reference coaxial cable group through the first port; collects the ground crosstalk peak information and the spatial crosstalk peak information of the crosstalk pulse signal at the other end of the crosstalk measurement coaxial cable group after being amplified by the signal amplification component through the second port; The signal processing component determines the crosstalk ratio of the crosstalk type according to the amplitude information, the ground crosstalk peak information and the spatial crosstalk peak information; wherein the crosstalk type includes a ground crosstalk type and a spatial crosstalk type, and the crosstalk ratio includes a ground crosstalk ratio and a spatial crosstalk ratio.

6. The crosstalk measurement device according to claim 5, characterized in that: 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 is the ground crosstalk ratio, V 地 is the ground crosstalk peak information, N is the amplification factor of the signal amplifying component, and V is the amplitude information.

7. The crosstalk measurement device according to claim 5, characterized in that: 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 is the spatial crosstalk ratio, V 电磁 is the spatial crosstalk peak information, N is the amplification factor of the signal amplifying component, and V is the amplitude information.

8. The crosstalk measurement device according to claim 5, characterized in that: When the crosstalk measurement method is performed in a room temperature environment, the reference coaxial cable group includes at least one coaxial cable group; or When the crosstalk measurement method is performed 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 via a preset line.

9. A dilution refrigerator, characterized in that: It comprises a crosstalk measurement device as described in any one of claims 5-8.

10. A superconducting quantum computing device, characterized in that: Comprising the dilution refrigerator as claimed in claim 9.

Images