CN219285284U - Measuring device and system - Google Patents

Abstract

The application discloses a measuring device and a measuring system, and belongs to the field of quantum computing. The measuring device comprises a resistance measuring instrument and a switching circuit. The resistance measuring instrument is provided with a first measuring joint and a second measuring joint; the switch circuit has a first port, a selection switch, and a plurality of second ports. The first measurement junction is electrically connected to a first port, the second port is electrically connected to a first electrode of the josephson junction, and the second measurement junction is electrically connected to a second electrode of the josephson junction. The measuring device can be used for measuring a plurality of Josephson junctions by one device, so that the problem of configuring a plurality of measuring devices can be avoided, and the measuring efficiency is improved.

Description

Measuring device and system

Technical Field

The present application belongs to the field of quantum information, in particular to the field of quantum computing technology, and in particular, the present application relates to a method of quantum information.

Background

In practical engineering, the superconducting qubit is mostly formed by using Josephson junction parallel capacitors.

Wherein the josephson junction can be equivalently a nonlinear inductance. Under the condition of stable process conditions, the normal temperature resistance of the Josephson junction has a certain corresponding relation with the bit frequency. Therefore, the bit frequency at extremely low temperature can be estimated by calibrating the normal temperature resistance of the Josephson junction, and the relevant performance of the superconducting qubit can be further estimated by the bit frequency.

Josephson junctions are heterostructures in the form of superconductor-insulator-superconductors, and most commonly Al-AlOx-Al junctions. This particular structure is extremely susceptible to the surrounding environment and this effect will lead to damage of the junction, such as electrostatic breakdown, etc.

In some practice, the junction resistance is tested using bond extraction to the package or extraction through a non-destructive probe station and then interconnected with the test meter. Typically, each set of meter test channels can only test one junction resistance. When testing multiple junctions or monitoring multiple junction resistances, it is necessary to add test meter channels or re-wire/move probes to the next junction, the operation is complex or the occupied meters are excessive, and the risk of junction damage is increased by excessive operation steps.

Disclosure of Invention

Examples of the present application provide a measurement apparatus and system that can be used in one device to test a plurality of josephson junctions, thus reducing the number of meters that need to be occupied for measurement, and operating less on the josephson junctions, which are less prone to junction damage.

The scheme exemplified by the application is implemented as follows.

In a first aspect, examples of the present application propose a measurement device that can be used to measure junction resistances of a plurality of josephson junctions.

The measuring device includes:

a resistance measuring instrument having a first measuring joint and a second measuring joint;

a switching circuit having a first port, a selection switch configured to controllably electrically connect the plurality of second ports one by one with the first port to form a plurality of conductive paths corresponding to the number of second ports and each being independent within a preset time range, the plurality of conductive paths being electrically conductive at the same time when there are no more than two conductive paths within the preset time range;

wherein the first measurement junction is electrically connected to a first port, the second port is configured to be electrically connected to a first electrode of the josephson junction, and the second measurement junction is configured to be electrically connected to a second electrode of the plurality of josephson junctions.

In the measuring device, the resistance measuring instrument is used as a direct measuring josephson junction for measuring the junction resistance thereof. And the switch circuit is an intermediate structure for electrically connecting the resistance measuring instrument and the electrodes of the plurality of Josephson junctions. Since the switching circuit can provide a plurality of conductive paths and each of the plurality of conductive paths can be selectively turned on or off, each josephson junction can be measured individually. The two electrodes of the plurality of josephson junctions are thus connected by means of the second port and the second measurement junction of the measuring device, and the junction resistance of each josephson junction is obtained by selecting the switching action during the test.

Since a surge may be generated when the selection switch is switched during the measurement, resulting in damage to the josephson junction or the measuring instrument, a protection circuit may be optionally configured.

In some examples of the present application, the first measurement connector is electrically connected to the first port indirectly through a first protection circuit; and/or the second port is configured to be indirectly electrically connected with the first electrode through the second protection circuit; and/or the second measuring joint is indirectly and electrically connected with the second electrode through a third protection circuit.

The protection circuit may employ various circuit structures known in the art. In some examples of the present application, the first protection circuit, the second protection circuit, and the third protection circuit are each independent surge voltage protection circuits; alternatively, any or all of the first protection circuit, the second protection circuit, and the third protection circuit are a single resistor or a multi-resistance series circuit.

In some examples of the present application, the selection switch comprises a mechanical switch; or the selection switch is a relay switch or a change-over switch; alternatively, the resistance meter includes a source meter.

In some examples of the present application, the measurement device further comprises a host computer having one or more of the following limitations;

first definition: the upper computer is configured to be electrically connected with the resistance measuring instrument so as to control the resistance measuring instrument to output an electric signal and collect measurement data from the resistance measuring instrument;

a second definition: the upper computer is configured to be electrically connected with the selection switch and operate the selection switch within a preset time range to form a plurality of conductive paths.

In some examples of the present application, the preset time range can be adjusted and implemented by configuration by the upper computer.

In a second aspect, examples of the present application provide a measurement system comprising:

the aforementioned measuring device; and

a contact device having a probe configured to confine the superconducting quantum chip and to electrically contact an electrode of a josephson junction in the superconducting quantum chip through the probe;

wherein the contacting means provides an electrical port through the probe to the electrode of the josephson junction;

a second port in the measurement device and a second measurement connector are matingly and electrically connected with an electrical port provided by the probe.

The configuration of the contact device can restrict the superconducting quantum chip, and avoid the chip from generating unexpected movement. Meanwhile, the probe can also enable the measuring device to be electrically connected with the electrode of the chip more conveniently, and the chip can be detached from the system conveniently after the measurement is completed. Thus, the system can more efficiently perform chip tests in multiple batches.

In some examples of the present application, the superconducting quantum chip is a bare chip; alternatively, the superconducting quantum chip is mounted to the package.

In some examples of the present application, the contacting means comprises:

a carrier having a chip slot for accommodating the superconducting quantum chip;

a plurality of probes connected to the carrier are configured to be electrically connected to electrodes of the josephson junctions of the superconducting quantum chip.

In some examples of the present application, the contact device further comprises a multi-axis displacement mechanism by which the plurality of probes are controllably movably connected to the stage;

and/or the contact device further comprises a cover plate detachably connected with the carrier, wherein the cover plate is configured to cover the chip groove and expose the electrode of the superconducting quantum chip positioned in the chip groove or expose the bonding pad of the superconducting quantum chip positioned in the chip groove, and the bonding pad is formed by extending the electrode of the superconducting quantum chip through a wire so as to be in electrical contact with the probe.

The beneficial effects are that:

the need exists for junction resistance measurements of multiple josephson junctions in a short or continuous period of time, and the measurement apparatus and system in the examples of this application can provide multiple interfaces that electrically mate with the electrodes of multiple josephson junctions, thereby eliminating the need for frequent disassembly or configuration of multiple sets of gauges. The different junctions are tested one by switching through a selection switch in the measuring device.

Drawings

For a clearer description, the drawings that are required to be used in the description will be briefly introduced below.

FIG. 1 is a schematic view of the structural principle of a measuring device in the example of the present application;

FIG. 2 is a schematic diagram showing the structure of the switching circuit in FIG. 1;

FIG. 3 is a schematic diagram of the structure of a probe in the measurement system exemplified by the present application;

fig. 4 is a schematic structural diagram of a measurement system in the example of the present application.

Reference numerals illustrate: 100-measuring device; 101-a resistance measuring instrument; 102-a switching circuit; 103-josephson junction; 201-a first port; 202-a second port; 203-a selection switch; 300-measuring system; 301-probe; 3011-a connection; 3012-contact; 3013-tip; 302-a carrier; 400-superconducting quantum chip.

Detailed Description

A quantum chip based on superconducting quantum circuit contains superconducting circuit structure such as quantum bit and microwave resonant cavity. The qubit is a two-level system formed by using a capacitor and a Josephson junction with nonlinear inductance characteristic. The electric parameter states of capacitance, inductance and the like of different targets are realized by designing the electric sensor into different shapes and sizes.

Wherein the performance of the josephson junctions (which may be simplified as described) affects the performance of the quantum chip to a large extent. In order to determine if the qubit is normal, there is a test need for josephson junctions. One of the important test items is to test the junction resistance of josephson junctions, such as the normal temperature resistance or junction resistance at various suitable temperatures. The normal temperature resistance of a josephson junction has a linear relationship with the bit frequency of the superconducting qubit constructed based on the josephson junction at low temperature. Thus, the resistance of the josephson junction affects the frequency of the corresponding superconducting qubit. Therefore, the primary screening efficiency of the sample can be improved by screening the sample with a proper resistance value.

A typical josephson junction is a device comprising two electrodes and a thin insulating barrier separating the two electrodes. And the materials of the two electrodes may exhibit a superconducting property at a critical temperature of themselves or a superconducting property below the critical temperature property.

For a single josephson junction, it is possible to choose to measure the resistance by voltammetry, e.g. two terminal method, by combining the two electrodes of the junction, without extensive measurement tasks; alternatively, resistance can be measured using a four-terminal method, such as Kelvin four-wire detection.

However, in practical development, especially when rapid technical iterations are required, the need for a short-term prescreening of a large number of junction resistances arises for evaluating very low temperature bit frequencies. Alternatively, there may be a need to monitor junction resistance over time and at different temperatures in order to study the stability of the josephson junctions. Therefore, for the task of continuously testing the junction resistances of a plurality of junctions or monitoring the junction resistances for a long time, it is necessary to configure a plurality of sets of measuring equipment, or to frequently disassemble the test meter and the line connection and disconnection operations when the measuring equipment is insufficient. These current situations indicate that the problem of rapid and convenient multi-junction measurement cannot be well solved at present.

To this end, the examples of the present application provide a measuring device, which overcomes the above-mentioned problems to a large extent. In general, the measuring device is capable of providing a plurality of interfaces. These interfaces can be connected to the electrodes of the josephson junction. Thus, when multiple junctions are to be tested, the electrodes of the junctions may be connected in advance through these interfaces. Junction resistance measurements are then made by selecting the connection of the two electrodes of any single junction to the meter, respectively. Wherein the selection of the measurement circuits to have different junctions measured may be by using switches to selectively turn on the corresponding junctions.

In other words, the scheme of switching different junctions into the measuring circuit is realized by frequently switching wires or providing more testing equipment, in the application, a plurality of junctions are selected to be switched into the measuring circuit through the design of the circuit in the measuring device, and then the conduction test of the measuring circuit of the different junctions is performed through the switching of the switch. Compared with the scheme of frequently replacing connection and configuring more measuring instruments, the scheme of using the switch to conduct different firm test schemes through switching in the application example has lower implementation cost, is more convenient to implement and has higher test efficiency.

The one measurement device in the example may be used to measure junction resistances of a plurality of josephson junctions. And it will be appreciated that although in the examples junction resistance measurements of josephson junctions are mainly described, in other examples the measurement apparatus may alternatively be used in applications where other resistance measurements are required, for example resistance measurements of various electrical components in a quantum chip.

In an example, as shown in fig. 1, the measuring apparatus 100 mainly includes a resistance measuring instrument 101 and a switching circuit 102, which have a structure as shown in fig. 2.

Wherein the resistance measuring instrument 101 has a first measuring joint and a second measuring joint. The first measurement junction and the second measurement junction of the resistance measurement instrument 101 are coupled to the two electrodes of the josephson junction 103, and measurements can be made. The first measuring joint and the second measuring joint can realize measuring resistance by a two-terminal method or a four-terminal method through proper selection and configuration. The resistance measuring instrument 101 is, for example, a source meter, lockin, nanovoltmeter, or the like.

The switching circuit 102 has a first port 201, a selection switch 203, and a plurality of second ports 202. The first port 201 is connected to a plurality of second ports 202 through a selection switch 203. And switching of the selector switch 203 may electrically connect the first port 201 to a specific one of the second ports 202. Also, the selection switch 203 can controllably electrically connect the plurality of second ports 202 to the first ports 201 one by one, thereby forming a plurality of conductive paths corresponding to the number of second ports 202 and each independently within a preset time range. And, a plurality of conductive paths do not exist more than two conductive paths in a preset time range and are electrically conducted at the same time.

It will be appreciated that the number of second ports 202 in the measurement apparatus 100 determines the number of josephson junctions 103 that the apparatus is able to make measurements. Also, it should be appreciated that when the number of knots to be measured is less than the number of second ports 202, there is no need to additionally configure more knots when using the measurement device 100. In short, not all of the second ports 202 in the measurement device 100 need to have all access to the circuitry. Similarly, not all of the measurement terminals of the resistance meter 101 need be connected to circuitry (more specifically, to a junction).

As a way of fitting the resistance measuring instrument 101 and the switching circuit 102, a first measuring terminal of the resistance measuring instrument 101 is electrically connected to the first port 201 of the switching circuit 102. The second port 202 of the switching circuit 102 is then arranged to be electrically connected to the first electrode of the josephson junction 103, while the second measurement connection is arranged to be electrically connected to the second electrodes of the plurality of josephson junctions 103.

In the example shown in fig. 1, the second measurement junction is electrically connected to the second electrodes of the three josephson junctions 103 by three branches. Meanwhile, the switching circuit 102 is electrically connected to the first electrodes of the three josephson junctions 103 described above via three second ports 202.

The switch circuit 102 may be implemented in various ways, and is not particularly limited in this application. For example, the selection switch 203 includes a mechanical switch; and the selection switch 203 may be a relay switch, or a change-over switch, for example. Other types or implementations of switching schemes may be selected for rapid switching and to improve automation of the test.

For example, in some examples, such switching circuit 102 may be described as having a current inlet and a plurality of current outlets in series, and having a switch, such as a single pole, multiple throw switch, at the current inlet and the plurality of current outlets that can be selected for switching by a user. Thus, it will be appreciated that the switching circuit 102 essentially provides a plurality of sub-circuits that are constructed in parallel. These sub-circuits are controlled to be on-off by the same device/switch and can be operated by the switch such that only one sub-circuit is electrically conducted together with the current inlet and the current outlet, respectively, to measure a single junction. For example, in the case of using a relay switch, the relay switch is controlled by the host computer, so that only one path of the relay switch is in an on state in a certain time node, and the other paths of the relay switch are in an off state.

For multiple junctions that need to be measured in a short time, the switch may be required to switch quickly, and there may be instances where the junction is destroyed. Thus, to implement a large number of junction measurements in a short period of time, a protection circuit may be configured in some examples to overcome the hazard of circuit surges at the time of switching.

For example, the measuring device 100 may be configured with a first protection circuit, and the first measuring tap of the resistance measuring instrument 101 is indirectly electrically connected to the first port 201 through the first protection circuit. Alternatively, the measurement device 100 may be configured with a second protection circuit, and the second port 202 of the switching circuit 102 is electrically connected indirectly to the first electrode through the second protection circuit. Alternatively, the measuring device 100 may be provided with a third protection circuit, and the second measuring tap of the resistance measuring instrument 101 meter is indirectly electrically connected to the second electrode through the third protection circuit. The protection circuits described above may be selectively arranged in one or more of them, and are limited in that the junction can be protected from damage.

The first protection circuit, the second protection circuit, and the third protection circuit may be of the same type, or may each be of a different type, or may be of a partially used type. And similar strategies can be adopted on specific structures or circuit structures of the protection circuit. Thus, the type or structure of each protection circuit, the circuit implementation can be adaptively adjusted according to the connected position, etc., so as to be able to achieve at least the protection junction as a limit, without other necessary limitations.

The first protection circuit, the second protection circuit and the third protection circuit are respectively independent surge voltage protection circuits. As an alternative specific example, any one or all of the first protection circuit, the second protection circuit, and the third protection circuit is a single resistor or a multi-resistance series circuit, that is, a single large-resistance resistor, or a plurality of small-resistance resistors are connected in series.

In addition, for the control of the switch, if the frequency of switching allows, manual control by an operator may be considered on the basis of the implementation based on the switch and if necessary. Alternatively, the switching operation of the switch may be performed in a manner selected to be non-manually operated in some cases. For example, when there is a fast switching to perform a multi-junction test, such as where a large number of junction measurements need to be made in a short time; in these cases, it is difficult to achieve high frequency switching by manual operation. Or when a long multi-junction measurement is required; in these cases, it is difficult to reach long duty by manual manipulation. In other words, the manual operation is difficult to meet in terms of switching frequency of the switch, switching for a long time, and the like.

Thus, in some examples, the measurement device 100 also includes an upper computer. The upper computer can execute corresponding switch switching operation by pre-solidifying the program or manually configuring the program according to the operation requirement of the site. And thus in such an example, the upper computer is configured to be electrically connected with the selection switch 203 and operate the selection switch 203 within a preset time range to form a plurality of conductive paths.

Further, the host computer may be configured to be linked with the resistance measuring instrument 101. Accordingly, the host computer may be electrically connected to the resistance measuring instrument 101, and thus may be used to control the resistance measuring instrument 101 to output an electrical signal and collect measurement data from the resistance measuring instrument 101.

Then, it is understood that in the case where the measuring apparatus 100 is configured with an upper computer, the upper computer may be selectively engaged with either one or both of the switching circuit 102 and the resistance measuring instrument 101. When the two are respectively matched with the upper computer, the measuring efficiency of the resistance of the multiple junction can be improved, and even the automatic rapid measurement is realized. For example, a preset time range and a measurement program that can be freely set are configured by the upper computer so that a specified number of knots are measured during the time period by automatically switching the switch and operating the measuring instrument.

The upper computer is a computer or a single chip microcomputer which can send operation instructions, and generally provides a user operation interaction interface and displays feedback data to a user. In some non-limiting examples, typical types of host computer devices include, for example: computers, cell phones, tablets, panels or touch screens, etc. In an example, the host computer is selected as a computer that can directly issue a manipulation command, such as a test computer with a control script.

In order to realize the corresponding functions, the upper computer can be configured with various lower computers, various proper devices or equipment, and can perform corresponding type selection, structure and functional configuration on the switch and the measuring instrument in the switch circuit 102 so as to adapt to the requirements of automatic or electric operation.

The example also proposes a measurement system 300 based on the above-described measurement apparatus 100, based on the consideration of further improving the measurement efficiency, simplifying the operation, and the like.

The measuring system 300 comprises a measuring device 100 and a contacting device. The measurement device 100 therein is similar in structure to the example measurement device 100 previously described. And the contact device have the same beneficial effects, and even have better use effect and use experience under the cooperation of the contact device and the contact device. Because of this, the measurement device 100 will not be described in detail here. Technical details relating to the measurement device 100 are not disclosed in relation to the measurement system 300 embodiments, and will be understood by those skilled in the art with reference to the above description.

The contact means are capable of confining the superconducting quantum chip 400 and are also in electrical contact with the electrodes of the josephson junctions 103 in the superconducting quantum chip 400 (e.g. a bare chip or a superconducting quantum chip 400 mounted in a package) by means of probes 301 configured as shown in fig. 3. The probe 301 is typically (but not necessarily) provided with elastic members so as to be capable of telescoping, and thus, the probe 301 can be pressed to the electrode by applying pressure, and is mated with the superconducting quantum chip 400 stably and nondestructively. The probes 301 may also be described as current probes 301, test probes 301, pcb-specific probes 301, pogo pins, etc.; and may be adapted based on superconducting quantum chip 400. The probe 301 generally has a contact portion 3012 with a tip 3013, and a connection portion 3011 to connect to other circuitry. The contact portion 3012 and the connection portion 3011 are sleeved on each other and engaged by an elastic element such as a spring.

In performing measurements using the measurement system 300, the contact means provides an electrical port through the probe 301 to the electrode of the josephson junction 103. Thus, the second port 202 and the second measurement connector in the measurement device 100 are matingly and electrically connected to the electrical port provided by the probe 301. Wherein the second port 202 and the second measurement structure may be selectively fixedly connected or detachably connected to the probe 301. By using the probe 301 as an intermediate structure for the connection between the measurement device 100 and the josephson junction 103 (superconducting quantum chip 400), the ease of chip mounting or dismounting, or more specifically the mating with the junction, can be improved.

It is noted that, due to the very small size of the josephson junction 103, the electrodes are typically routed through the wires by wire bonding using pads arranged to form the wires together when the junction is made, and then electrically contacted or connected to measurement circuitry (e.g. probe 301) through the pads.

A schematic structural diagram of a measurement system 300 is schematically shown in fig. 4. It is noted that it is necessary to connect two electrodes of a junction, such as metallic aluminum electrodes at both ends of aluminum oxide as an insulating layer, when measuring the resistance of the junction as described above. In fig. 4, only the superconducting quantum chip 400 is drawn to be connected to the measuring device 100 by one line, but this is merely a simplified illustration; it should be understood that it represents a matching electrical connection of superconducting quantum chip 400 to second port 202 of measurement device 100 and a second measurement junction to an electrical port provided by probe 301.

Although the description may vary, the contact device in the present application may use various probe 301 stages known to the inventors, in particular, a detection device for use in the testing of the superconducting quantum chip 400 and realized based on the probe 301. Illustratively, the contact device in the example has a carrier 302, and the carrier 302 also has a chip slot that accommodates the superconducting quantum chip 400.

Further, the contact device also has a plurality of probes 301 connected to a stage 302; these probes 301 can be electrically connected to the electrodes of the josephson junctions 103 of the superconducting quantum chip 400 as described previously. In some examples, the contact device has a pair of probes 301, such as two probes 301. When measurements are required for different junctions, the probe 301 may be moved, optionally in combination with a switch in the measuring device 100.

Accordingly, the contact device in the measurement system 300 may also be configured with a multi-axis displacement mechanism for moving the probe 301. Wherein the probes 301 are controllably coupled to a stage 302 in a movable manner by a multi-axis displacement mechanism. The multi-axis displacement mechanism is, for example, an XYZ three-axis displacement mechanism. For example by cooperating with guide rails, screws, sliders, motors, speed reducers, linear motors, cylinders, etc.; those skilled in the art can obtain the related art through existing commercial products or disclosures, and the detailed description thereof will be omitted herein.

Considering that small relative movements of the contact between the probe 301 and the chip, such as slight shifts in the contact position (even if still in contact), may have an unacceptable impact on the measurement results and the quality of the junction, it is also possible in some examples to provide a cover plate in the contact device that is detachably connected to the carrier 302.

The cover plate may be removably coupled to the carrier 302. When the two are connected, the cap plate may cover the chip groove and expose the electrode of the superconducting quantum chip 400 located in the chip groove or expose the pad of the superconducting quantum chip 400 located in the chip groove. Wherein the pads are formed by extending electrodes of the superconducting quantum chip 400 through wires for electrical contact with the probes 301.

The embodiments described above by referring to the drawings are exemplary only and are not to be construed as limiting the present application.

For purposes of clarity, technical solutions, and advantages of embodiments of the present application, one or more embodiments have been described above with reference to the accompanying drawings. Wherein like reference numerals are used to refer to like elements throughout. In the description above, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that one or more embodiments may be practiced without these specific details, and that such embodiments may be incorporated by reference herein without departing from the scope of the claims.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The foregoing detailed description of the construction, features and advantages of the present application will be presented in terms of embodiments illustrated in the drawings, wherein the foregoing description is merely illustrative of preferred embodiments of the application, and the scope of the application is not limited to the embodiments illustrated in the drawings.

Claims (10)

1. A measurement device for measuring junction resistance of a plurality of josephson junctions, the measurement device comprising:

a resistance measuring instrument having a first measuring joint and a second measuring joint;

a switching circuit having a first port, a selection switch configured to controllably electrically connect the plurality of second ports one by one with the first port to form a plurality of conductive paths corresponding to the number of second ports and each being independent within a preset time range, the plurality of conductive paths being electrically conductive at the same time when there are no more than two conductive paths within the preset time range;

wherein the first measurement junction is electrically connected to a first port, the second port is configured to be electrically connected to a first electrode of the josephson junctions, and the second measurement junction is configured to be electrically connected to a second electrode of the plurality of josephson junctions.

2. The measurement device of claim 1, wherein the first measurement connection is electrically connected to the first port indirectly through a first protection circuit;

and/or the second port is configured to be indirectly electrically connected with the first electrode through a second protection circuit;

and/or the second measuring joint is indirectly and electrically connected with the second electrode through a third protection circuit.

3. The measurement device of claim 2, wherein the first protection circuit, the second protection circuit, and the third protection circuit are respective independent surge voltage protection circuits;

alternatively, any or all of the first protection circuit, the second protection circuit, and the third protection circuit are a single resistor or a multi-resistance series circuit.

4. The measurement device of claim 1, wherein the selection switch comprises a mechanical switch;

or the selection switch is a relay switch or a change-over switch;

alternatively, the resistance meter includes a source meter.

5. The measurement device of claim 1, further comprising a host computer, the host computer having one or more of the following limitations;

first definition: the upper computer is configured to be electrically connected with the resistance measuring instrument so as to control the resistance measuring instrument to output an electric signal and collect measurement data from the resistance measuring instrument;

a second definition: the upper computer is configured to be electrically connected with the selection switch and operate the selection switch within a preset time range to form the plurality of conductive paths.

6. The measurement device of claim 5, wherein the preset time range is adjustable and is configured by the host computer.

7. A measurement system, comprising:

the measurement device according to any one of claims 1 to 6; and

a contact device having a probe configured to confine the superconducting quantum chip and to electrically contact an electrode of a josephson junction in the superconducting quantum chip through the probe;

wherein the contact means provides an electrical port through the probe to the electrode of the josephson junction;

a second port and a second measurement connector in the measurement device are electrically connected in matching with an electrical port provided by the probe.

8. The measurement system of claim 7, wherein the superconducting quantum chip is a bare chip; alternatively, the superconducting quantum chip is mounted to the package.

9. The measurement system of claim 7, wherein the contact device comprises:

a carrier having a chip slot for accommodating the superconducting quantum chip;

a plurality of probes connected to the carrier are configured to be electrically connected to electrodes of josephson junctions of the superconducting quantum chip.

10. The measurement system of claim 9, wherein the contacting device further comprises a multi-axis displacement mechanism by which the plurality of probes are controllably movably coupled to the stage;

and/or the contact device further comprises a cover plate detachably connected with the carrier, wherein the cover plate is configured to cover the chip groove and expose the electrode of the superconducting quantum chip positioned in the chip groove or expose the bonding pad of the superconducting quantum chip positioned in the chip groove, and the bonding pad is formed by extending the electrode of the superconducting quantum chip through a wire so as to be in electrical contact with the probe.

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