Semiconductor device

Abstract

To achieve data communication via wiring with low power consumption in a semiconductor device.SOLUTION: A second control device includes a signal modulation section that changes the impedance of a path by selecting one of two control values, and a first control device includes a signal demodulation section that reproduces a data value from the impedance of the path.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device. [Background technology]

[0002] The performance improvements achieved through miniaturization of semiconductor elements, which have supported the advancement of computers for over half a century, are expected to reach their limits in the near future due to the comparison between process rules and the interatomic distance of silicon.

[0003] Quantum computers are an attempt to overcome these limitations through new computational principles and devices, and quantum computing devices and computing methods have been proposed that utilize superconducting circuits, ion traps, photons, silicon quantum dots, etc. In addition, as a preliminary step toward the future vision of running large-scale, practical applications on error-tolerant general-purpose quantum computer systems, progress is currently being made in demonstrating the principle and exploring algorithms for a system called NISQ (Noisy Intermediate-Scale Quantum Device), which is based on the concept that the number of qubits is small (around 100), making quantum error correction impossible.

[0004] To realize a quantum computer system that applies quantum computing devices that operate on quantum effects that manifest at extremely low temperatures, such as the spin of a single electron in a silicon quantum dot, it is common to choose a dilution refrigerator as the device to incorporate the device into.

[0005] In this case, the quantum computing device is in thermal contact with the mixing chamber, which has the lowest temperature within the dilution refrigerator, and is cooled to, for example, about 100 mK. Various signals required to control the operation of the quantum computing device are generated in a region inside the dilution refrigerator that is hotter than the mixing chamber, and / or by instrumentation equipment (including semiconductor chips) located outside the dilution refrigerator. Similarly, measurements to obtain the quantum dot state, which is the calculation result, are performed using these instrumentation equipment, which is typically configured like an experimental device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2002-501329 [Patent Document 2] Special Publication No. 2019-533353 Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 discloses a technology for achieving signal transmission by comparing, on the transmitting means side, a transmission signal from a transmitting means with a reflected signal having a predetermined meaning that is reflected from a receiving means due to intentional impedance mismatch, and interpreting the information superimposed on the signal, in relation to communication between devices connected by a transmission line.

[0008] Patent Document 2 discloses a technology in which a master device and at least one slave device are connected via a current loop path, and by opening and closing switches and bypass circuits that constitute part of the path based on a predetermined procedure, the total impedance of the path can be varied along the time axis, and this technology is used to notify device status and transmit operation requests.

[0009] A quantum computer that uses quantum operation devices with an array of quantum dots as its operation elements effectively behaves as an analog computer endowed with analog information in the form of electron spin. To achieve the desired fidelity of quantum operations, which determines the ultimate calculation accuracy of a quantum computer, it is not enough to simply combine and connect instrumentation devices, such as bias voltage generators and high-frequency generators with sufficient accuracy and characteristics, and minute voltage / current amplifiers used to read the electron spin state of quantum dots, to the quantum operation device.

[0010] In other words, the requirement is to specify the order and content of operation of each device so that cooperation between instrumentation devices is possible according to the quantum operations to be performed, and to realize sequence control that matches (synchronizes) the relative operation timing with high time precision (for example, 10 nanoseconds).

[0011] Furthermore, future trends in quantum computer technology, specifically the scaling up of quantum computers by increasing the number of quantum dots, and the advancement of system control, including improved functionality such as dynamic acquisition / calibration of quantum dot characteristics and quantum error correction, are expected to further increase the importance of collaboration between the increased number of control layers.

[0012] To make this possible, in addition to a means of communication in the downstream direction, i.e., from the upper level to the lower level in the control hierarchy, an upstream communication means is required that combines sufficient time accuracy with strict power consumption constraints, starting from a quantum computing device placed in an extremely low temperature environment or a control device that acts as an instrumentation device that controls the quantum computing device.

[0013] In quantum computers, communication is performed via wiring between stages with different temperatures. In data communication between devices with significantly asymmetric power consumption constraints due to temperature differences in the cryogenic region, driver circuits and resistive elements for impedance matching are required for communication from the device with stricter constraints, but the power consumption caused by these may make it impossible to comply with the constraints.

[0014] In Patent Document 1, communication between devices is carried out via a transmission line, but quantum computers are not envisioned, and the asymmetry of power consumption constraints is not taken into consideration.

[0015] Furthermore, Patent Document 2 does not take into consideration the asymmetry of power consumption constraints. Furthermore, although the impedance is modulated by a switching means, this is not desirable because the power consumption constraints on the slave device side are strict.

[0016] In the first place, Patent Documents 1 and 2 do not describe at all a quantum computer that provides a low-power communication means necessary for high-speed control of quantum operations that can be applied to devices in cryogenic environments where power consumption constraints are particularly asymmetric.

[0017] An object of the present invention is to realize data communication via wiring in a semiconductor device with low power consumption. [Means for solving the problem]

[0018] A semiconductor device according to one embodiment of the present invention has a first control device and a second control device, and performs data communication between the first control device and the second control device. The semiconductor device is arranged between the first control device and the second control device, and includes a path including at least two wires through which currents flow in opposite directions. The second control device has a signal modulation unit that receives input of a binary control value and changes the impedance of the path by selecting one of the binary control values ​​based on a data value to be output to the first control device. The first control device has a power supply that outputs an approximately constant current or an approximately constant voltage to the path, and a signal demodulation unit that regenerates the data value from the impedance of the path. [Effects of the Invention]

[0019] According to one embodiment of the present invention, in a semiconductor device, data communication via wiring can be achieved with low power consumption. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a block diagram showing a configuration of a communication interface in a quantum computing system 1 according to a first embodiment. [Figure 2] FIG. 10 is a block diagram showing the configuration of a signal modulation unit 320. [Figure 3] FIG. 2 is a block diagram showing the configuration of a signal demodulation unit 230. [Figure 4]FIG. 3 is a diagram illustrating the characteristics and operating points of an impedance modulation circuit 3211 according to the first embodiment. [Figure 5] 4 is a timing chart showing a modulation / demodulation operation according to the first embodiment. [Figure 6] FIG. 10 is a block diagram showing the configuration of a communication interface in a quantum computing system 1A according to a second embodiment. [Figure 7] FIG. 2 is a block diagram showing the configuration of a signal demodulation unit 240. [Figure 8] FIG. 10 is a diagram illustrating the characteristics and operating points of an impedance modulation circuit 3211 according to the second embodiment. [Figure 9] 10 is a timing chart showing a modulation / demodulation operation according to the second embodiment. [Figure 10] FIG. 10 is a block diagram showing the configuration of a communication interface in a quantum computing system 1B according to a third embodiment. [Figure 11] FIG. 10 is a block diagram showing the configuration of a signal modulation unit 330. [Figure 12] FIG. 2 is a block diagram showing the configuration of a signal demodulation unit 250. [Figure 13] 10 is a timing chart showing a modulation / demodulation operation according to the third embodiment. [Figure 14] FIG. 10 is a block diagram showing the configuration of a communication interface in a quantum computing system 1C according to a fourth embodiment. [Figure 15] FIG. 2 is a block diagram showing the configuration of a sequence control unit 280. [Figure 16] FIG. 2 is a block diagram showing the configuration of a signal demodulation unit 260. [Figure 17] FIG. 10 is a table showing an example of settings in a control sequence table 2820. [Figure 18] 10 is a timing chart showing a procedure of control sequence synchronous inter-device communication according to the fourth embodiment. [Figure 19] FIG. 1 is a block diagram showing a typical configuration of a quantum computing system 10. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same or corresponding numerals. Note that the accompanying drawings show embodiments and examples according to the principles of the present disclosure, but these are for understanding the present disclosure and are not to be used to interpret the present disclosure in a limiting manner. The descriptions in this specification are merely typical examples and are not intended to limit the scope or application of the present disclosure in any way.

[0022] Although the present embodiment has been described in sufficient detail to enable a person skilled in the art to implement the present disclosure, it should be understood that other implementations and forms are possible, and that changes in configuration and structure and substitutions of various elements are possible without departing from the scope and spirit of the technical idea of ​​the present disclosure. Therefore, the following description should not be interpreted as being limited thereto.

[0023] In the configurations of the embodiments described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and redundant explanations may be omitted.

[0024] When there are multiple elements having the same or similar functions, they may be described using the same reference numeral with different subscripts. However, when there is no need to distinguish between multiple elements, the subscripts may be omitted.

[0025] The terms "first," "second," and the like used in this specification are used to identify components and do not necessarily limit the number, order, or content of the components. Furthermore, numbers used to identify components are used in different contexts, and numbers used in one context do not necessarily indicate the same configuration in another context. Furthermore, this does not prevent a component identified by a certain number from also fulfilling the function of a component identified by another number.

[0026] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings etc. may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings etc.

[0027] The publications, patents, and patent applications cited herein are incorporated by reference in their entirety as part of the description of this specification. Elements referred to in the singular herein include the plural unless the context clearly dictates otherwise.

[0028] In the examples, as an example, a quantum computer system is described that combines multiple instrumentation / control devices placed in an ambient temperature environment ranging from room temperature to extremely low temperatures, and that combines these devices to operate in coordination with high timing accuracy to achieve desired quantum operations.The examples describe a configuration that provides a low-power communication means suitable for data communication between devices with significantly asymmetric power consumption constraints, as well as a quantum computer system that includes the communication means.

[0029] A quantum computing system according to one embodiment of the present invention comprises a path including at least two wires through which currents flow in opposite directions between a first control device that has a power consumption margin and is the receiving end of data communication, and a second control device that has strict power consumption constraints and is the sending end of data communication, wherein the second control device further comprises an impedance modulation circuit that changes the impedance of the path based on a data value output to the first control device, and the first control device further comprises a voltage that outputs an approximately constant current or an approximately constant voltage to the path, and a signal regeneration circuit that regenerates the data value from the impedance of the path.

[0030] The impedance modulation circuit is typically a circuit whose impedance can be varied depending on the voltage value applied to the control input, and by selecting one of the two control values ​​(voltage values) input to the second control device according to the data value and combining it with a modulation signal generation function to apply it to the control input, impedance modulation based on the data value becomes possible.

[0031] According to the data communication method of the embodiment, there is no need to implement termination elements for impedance matching or driver circuits capable of driving high loads related to long-distance wiring, which are the main causes of increased power consumption. This makes it possible to provide a low-power communication means that can be applied to devices with strict power consumption constraints, and to realize a highly functional and practical quantum computing system in which multiple instrumentation devices and control devices work together.

[0032] First, with reference to FIG. 19, a typical configuration of a quantum computing system 10 that is the premise of the present invention will be described.

[0033] This system combines a system control device 100 and instrumentation devices 1010, 1020, and 1030, all of which are placed in a room temperature environment 20, a first control device 200 placed on a 4K plate 30 where the ambient temperature inside the dilution refrigerator (not shown) is about 4 Kelvin (approximately -269°C), and a second control device 300 placed on a mixing chamber plate 40 where the ambient temperature inside the dilution refrigerator (not shown) is about 100 milliKelvin (approximately -273°C).

[0034] The inside and outside of the dilution refrigerator, and the plates within the dilution refrigerator, are connected by multiple normal-conducting or superconducting cables (not shown) with lengths ranging from several tens of centimeters to several meters in order to obtain the desired thermal conductivity and signal transmission characteristics.

[0035] The system control device 100 generates control instruction information based on the quantum operation to be executed, and sends the control instructions to the first control device 200 and the instrumentation devices 1010, 1020, and 1030 via communication means 101, 1001, 1002, and 1003, respectively.

[0036] The instrumentation device 1010 has a bias voltage control function 1011 and outputs a predetermined bias voltage 1012 based on control instruction information from the communication means 1001. The instrumentation device 1020 has a high-frequency signal generation function 1021 and outputs a predetermined high-frequency signal 1022 based on control instruction information from the communication means 1002. The instrumentation device 1030 has a current / voltage measurement function 1031 and measures an output signal 3005 output by the second control device 300 based on control instruction information from the communication means 1003. The measurement results can be read out from the system control device 100 via the communication means 1003.

[0037] The first control device 200 has an operation setting function 2001, a sequence control function 2002, and a data communication function 2003, and generates new local control instruction information for the second control device 300 based on control instruction information from the communication means 101, and sends a control instruction to the second control device 300 via control means 2004. In addition, based on a response signal 3004 output by the second control device 300, the first control device 200 updates the local control instruction information and outputs information indicating its own operating status and / or the contents of the response signal 3004 to the system control device 100 as an output signal 232. The response signal 3004 and the output signal 3005 may be the same signal.

[0038] The second control device 300 includes a quantum operation control function 3001, a quantum operation execution function 3002, and a data communication function 3003, temporarily stores control instruction information from the control means 2004, executes quantum operations in accordance with instructions in the stored control instruction information, and outputs information indicating its own operating status and / or the result of the quantum operation to the first control device 200 as the response signal 3004. The result of the quantum operation is further output to the instrumentation device 1030 as the output signal 3005.

[0039] The present invention relates to a gate-type quantum computer system, and more particularly to a device-to-device communication method for configuring a system in which a quantum computing device having an array of single-electron spin quantum dots in a cryogenic environment is connected to one or more control devices and / or instrumentation devices in a temperature environment higher than the cryogenic environment to generate control signals and measure computation results. The following describes the embodiments with reference to the accompanying drawings. [Example]

[0040] 1 shows the configuration of a quantum computing system 1 according to a first embodiment of the present invention. This embodiment is a system formed by combining a second control device 300 having a function of executing predetermined processing (which may include quantum operations using quantum dots) and outputting the execution results, a system control device 100 having a system setting function for setting and managing the entire system, and a first control device 200 that controls the operation of the second control device 300 and the reading of output from the second control device 300. It should be noted that, to avoid cluttering the drawing, components, interfaces, and other functions that are not directly involved in data transfer between devices according to the present invention are omitted.

[0041] The system control device 100 is usually installed in a room temperature environment (e.g., 20°C). On the other hand, the semiconductor chip constituting the second control device 300 is installed in an extremely low temperature environment (approximately -273°C) realized by a mixing chamber, which is the lowest temperature in a cooling device such as a dilution refrigerator, and the first control device 200 (including the aspect of the semiconductor chip) is installed in an environment (e.g., -269°C) that is hotter than the extremely low temperature environment in a dilution refrigerator.

[0042] The system control device 100 is a general information processing device equipped with a microprocessor, memory, storage device, input device, output device, etc. (not shown), and is assumed to run a system control application that realizes the system setting function. The system setting function may include, for example, a function to perform device-specific settings on the instrumentation devices (including the first control device 200) that make up the system, a function to acquire execution results in the second control device 300 that are read out according to a predetermined procedure, and may additionally include a function to monitor and manage the operating status of the entire quantum computing system 1.

[0043] The system control application performs predetermined communications, such as supplying specific setting information to the first control device from the system control device 100 via communication means 101 based on the information to be set as the initial state of the quantum computing system 1 or the results of interpreting the control sequence of the quantum operation specified by the user as the target to be executed, and transferring the output signal 232 output from the first control device 200 to the system control device 100.

[0044] Here, the communication means 101 and the output signal 232 may be interfaces based on standard communication specifications such as USB (trademark), SPI (trademark), I2C (trademark), RS-232C, GP-IB, PCI Express (trademark), Ethernet (trademark), etc., or may be unique specifications based on a general-purpose input / output port.

[0045] The first control device 200 includes an operation setting unit 210, a voltage generating unit 220, and a signal demodulating unit 230. The operation setting unit 210 instructs the voltage value to be output by the voltage generating unit 220 via voltage setting unit control means 211 based on setting information supplied from the system control device 100 by the communication means 101.

[0046] Upon receiving the instruction, the voltage generating unit 220 outputs an H-side reference control voltage 221 (VGSH) and an L-side reference control voltage 222 (VGSL), which usually have different voltage values, to the second control device 300, and outputs a reference threshold voltage 223 (VRTH) to the signal demodulating unit 230.

[0047] In addition, depending on the power consumption constraints, output voltage stability, etc. imposed on the first control device 200 due to the implementation requirements of the quantum computing system 1, the system configuration and the interface of the first control device 200 may be changed so that at least a portion of the H-side reference control voltage 221, the L-side reference control voltage 222, and the reference threshold voltage 223 are output from an instrumentation device independent of the first control device 200.

[0048] The signal demodulation unit 230 outputs an outgoing signal, i.e., outgoing communication means 231 (OUTWARD), required for inter-device data communication based on impedance modulation to the second control device 300, and also receives a return signal, i.e., return communication means 321 (RETURN), as an input to regenerate the data value before impedance modulation, and outputs the result to the system control device 100 as the output signal 232. A more detailed internal configuration and operation will be described later with reference to another drawing. The second control device 300 is configured to include a function unit 310 and a signal modulation unit 320.

[0049] The functional unit 310 executes a predetermined process (which may include quantum operations by quantum dots if quantum dots are integrated in the second control device 300) under control of a control means (not shown), and outputs, although not limited to, a binary representation of the execution result as a functional unit output signal 311 (DOUT) to the signal modulation unit 320. The execution result may be, for example, an operating state of the functional unit 310, a value that can identify the execution timing of at least one of the predetermined processes, or a value obtained by converting the quantum state of at least one of the quantum dots into a binary representation.

[0050] The signal modulation unit 320 incorporates an impedance modulation unit whose impedance can be varied depending on the voltage value applied to the control input. Based on the state (binary value) of the functional unit output signal 311, either the H-side reference control voltage 221 or the L-side reference control voltage 222 can be selected as the control input, thereby modulating the impedance between the outgoing path communication means 231 and the incoming path communication means 321. A more detailed internal configuration and operation will be described later with reference to other drawings.

[0051] In comparison with the typical configuration of the quantum operation system 10 described in conjunction with Figure 19, the H-side reference control voltage 221, the L-side reference control voltage 222, and the outbound communication means 231 correspond to part of the control means 2004, and the return communication means 321 corresponds to part of the response signal 3004, respectively.

[0052] 2 is a block diagram showing a detailed configuration of the signal modulation section 320. The signal modulation section 320 includes a modulated signal generation section 3200 and an impedance modulation section 3210.

[0053] Modulation signal generation unit 3200 is functionally equivalent to a two-input, one-output analog multiplexer circuit. Modulation signal generation unit 3200 is composed of switch circuits 3201 and 3202, both of which are turned on when the state of their control inputs is 1 or H, and an inversion circuit 3203 that inverts the logical state. In addition, it has, as an internal signal, functional unit output inverted signal 3204, the logical state of which is the functional unit output signal 311 inverted by inversion circuit 3203.

[0054] When the state of the functional unit output signal 311 is 1 or H (i.e., when the functional unit output inversion signal 3204 is 0 or L), the switch circuit 3201 is on and the switch circuit 3202 is off, and the voltage applied to the H-side reference control voltage 221 is output to the impedance modulation unit 3210 as modulation signal 3205.

[0055] When the state of the functional unit output signal 311 is 0 or L (i.e., when the functional unit output inverted signal 3204 is 1 or H), the switch circuit 3201 is turned off and the switch circuit 3202 is turned on, and the voltage applied to the L-side reference control voltage 222 is output to the impedance modulation unit 3210 as the modulation signal 3205. In other words, the voltage value of the modulation signal 3205 takes one of two values ​​depending on the state of the functional unit output signal 311.

[0056] The impedance modulation unit 3210 is an impedance modulation circuit 3211 whose impedance characteristics are variable according to the voltage value applied to a control input. From the viewpoint of reducing power consumption, the simpler the impedance modulation circuit 3211, the more preferable it is, and one implementation form thereof is an N-channel field effect transistor operating in enhancement mode. Note that the gate terminal, source terminal, and drain terminal indicated by symbols G, S, and D are connected to the modulation signal 3205, the outbound communication means 231, and the return communication means 321, respectively.

[0057] The impedance characteristics of the impedance modulation circuit 3211, i.e., the current-voltage (IDS-VDS) characteristics between the drain terminal and the source terminal, correspond to the binary voltage values ​​input from the modulation signal 3205 and are one of two curves statically determined from the voltage applied between the gate terminal and the source terminal.

[0058] Since the transmission impedances of the outbound communication means 231 and the return communication means 321 are usually fixed values, by measuring the total impedance value of the communication path, which is the sum of the transmission impedances of the outbound communication means 231 and the return communication means 321 and the impedance of the impedance modulation unit 3210, using a predetermined procedure described below, the output state of the functional unit output signal 311 can be reproduced as an approximately instantaneous value on the signal demodulation unit 230 side without introducing a complex communication protocol that leads to increased power consumption and time fluctuations.

[0059] 3 is a block diagram showing a detailed configuration of the signal demodulation unit 230. The signal demodulation unit 230 includes a constant current source 2300, a voltage input impedance measurement unit 2330, and a signal reproduction unit 2360.

[0060] The constant current source 2300 is a power supply circuit that outputs a substantially constant current, which is required to measure the total impedance of the communication path, and which has a value fixed at the time of design or a value that can be changed by a procedure not shown, and its current output is connected to the outbound communication means 231.

[0061] The output current value of the constant current source 2300 can be selected so that the drain terminal-source terminal voltage (VDS) in the impedance modulation circuit 3211 during impedance modulation operation is the minimum necessary voltage change, for example, 300 mV, taking into consideration the balance between the signal-to-noise ratio requirements required for the communication path and the power consumption of the impedance modulation circuit 3211 itself, thereby reducing unnecessary power consumption.

[0062] The voltage input impedance measurement unit 2330 is a differential amplifier circuit 2331 having a fixed gain G, and amplifies the differential voltage between the outbound communication means 231 and the return communication means 321 (grounded within the signal demodulation unit 230) by G times in order to measure the total impedance of the communication path. The amplified voltage is output as an amplified signal 2332. Here, the fixed gain G should be selected so that the amplified signal 2332 is equal to or lower than the power supply voltage of the first control device 200 and equal to or lower than the maximum input voltage allowed by the signal regeneration unit 2360.

[0063] The signal regeneration unit 2360 is a comparison circuit 2361 itself that determines the magnitude relationship between two positive and negative voltage inputs, and outputs a voltage representing 1 or H in binary representation if the voltage value of the amplified signal 2332 is smaller than the voltage value of the reference threshold voltage 223, and 0 or L if not.

[0064] The output of the comparison circuit 2361 connected to the output signal 232 corresponds to the output value of the functional unit output signal 311, which is reproduced based on the total impedance measurement result of the communication path. Note that a method for selecting a voltage value to be set as the reference threshold voltage 223 will be described later.

[0065] Whether the amplified signal 2332 and the reference threshold voltage 223 should be connected to the positive or negative input of the comparison circuit 2361 depends on the impedance characteristics of the impedance modulation circuit 3211. That is, when the magnitude relationship between the voltage values ​​of the functional unit output signal 311 and the magnitude relationship between the potential difference (the difference between the voltage value of the outbound communication means 231 and the voltage value of the return communication means 321) generated by the impedance modulation circuit 3211 is reversed, the amplified signal 2332 is connected to the negative input of the comparison circuit 2361; otherwise, the amplified signal 2332 is connected to the positive input, thereby enabling the intended signal reproduction operation.

[0066] FIG. 4 is a diagram showing the characteristics and operating points of the impedance modulation circuit 3211 according to the first embodiment.

[0067] The drain-source current-voltage (IDS-VDS) characteristics and operating point of the impedance modulation circuit 3211 change as follows according to the gate-source voltage (VGS) applied from the modulation signal 3205:

[0068] (1) When the functional unit output signal 311 (DOUT) is 1 or H, the voltage value of VGS becomes approximately equal to the voltage value of the H-side reference control voltage 221 (VGSH), resulting in the impedance characteristics shown by the curve CURH. At this time, the intersection OPH with the line ISUP, which has a value equal to the current value output by the constant current source 2300, becomes the operating point, and the horizontal axis (VDS) component is the voltage value (VDSH) of VDS.

[0069] (2) When the functional unit output signal 311 (DOUT) is 0 or L, the voltage value of VGS becomes approximately equal to the voltage value of the L-side reference control voltage 222 (VGSL), resulting in the impedance characteristics shown by the curve CURL. At this time, the intersection OPL with the line ISUP, which has a value equal to the current value output by the constant current source 2300, becomes the operating point, and the horizontal axis (VDS) component is the voltage value (VDSL) of VDS.

[0070] In order to reduce the power consumption of the impedance modulation circuit 3211, it is effective to suppress the output current of the constant current source 2300 in order to reduce the voltage fluctuation of VDS.

[0071] However, in an actual system, the curves CURH and CURL and the straight line ISUP have widths that correspond to variations in characteristics due to manufacturing variations in the impedance modulation circuit 3211, variations in characteristics due to fluctuations in ambient temperature during operation, and the stability of the output current of the constant current source 2300, and it is necessary to take into account that the intersection points OPH and OPL, which correspond to the operating points, also fluctuate within a specific current / voltage range.

[0072] In order to enable the signal demodulation unit 230 to distinguish the voltage values ​​of VDS (VDSH and VDSL) at the two operating points, it is preferable to select the output current of the constant current source 2300 on the condition that the specific current-voltage ranges related to the intersections OPH and OPL do not overlap and are separated by at least a predetermined voltage margin required by the system.

[0073] 5 is a timing chart showing, from an overview, the operation of impedance modulation data communication realized between the signal modulation unit 320 and the signal demodulation unit 230 in Example 1. As an example, it shows that the time-series data (consecutive values ​​1 and 0) output by the function unit 310 is correctly reproduced by the signal reproduction unit 2360.

[0074] Via the functional unit output signal 311, the signal modulation unit 320 that has received the data to be output by the functional unit 310 performs an impedance modulation operation based on the data value (1(H) or 0(L)). As a result of the modulation operation, a potential difference of VDSH or VDSL occurs between the terminal on the signal modulation unit 320 side of the forward communication means 231 and the terminal on the signal modulation unit 320 side of the reverse communication means 321.

[0075] The terminal on the signal demodulation unit 230 side of the reverse communication means 321 is grounded internally and connected to the negative input of the differential amplifier circuit 2331, and a voltage with a value obtained by superimposing an offset (OFST) on VDSH or VDSL is applied to the positive input.

[0076] The offset corresponds to the voltage drop due to the total transmission impedance of the forward communication means 231 and the reverse communication means 321, and becomes a substantially fixed value that usually does not depend on the data value, excluding variations caused by the environmental temperature gradient of the transmission cable. The differential amplifier circuit 2331 with a fixed gain G outputs, as the amplified signal 2332, a signal having a voltage value of (VDSH + OFST) × G or (VDSL + OFST) × G.

[0077] [[ID=1"]]

[0078] In the connection form to the comparison circuit 2361 described above, a correct comparison result can be obtained only when the impedance modulation circuit 3211 has a modulation characteristic that satisfies VDSH < VDSL. When the modulation characteristic becomes VDSH > VDSL, it is advisable to swap the connections of the positive input and the negative input of the comparison circuit 2361.

[0079] Furthermore, the voltage value of the reference threshold voltage 223 may be selected to be approximately the center of the voltage fluctuation range of the amplified signal 2332, and can be determined experimentally after the quantum operation system 1 is constructed.

[0080] Thus, Example 1 is a semiconductor device (1) having a first control device (200) and a second control device (300), and performing data communication between the first control device (200) and the second control device (300).

[0081] The control device is provided with a path including at least two wires (231, 321) disposed between the first control device (200) and the second control device (300) and through which currents flow in opposite directions.

[0082] The second control device (300) has a signal modulation unit (320) that receives binary control values ​​(221, 222) as input and changes the impedance of the path (231, 321) by selecting one of the binary control values ​​(221, 222) based on a data value (311) to be output to the first control device (200).

[0083] The first control device (200) has a power supply (2300) that outputs an approximately constant current or an approximately constant voltage to the path, and a signal demodulation unit (230) that recovers the data value from the impedance of the path (231, 321).

[0084] The reason why we use the term "approximately constant current" or "approximately constant voltage" is that even if the current or voltage value is not completely constant (i.e., even if there is a certain degree of error), it will operate normally as long as the operating point can be clearly separated.

[0085] The signal modulation unit (320) has an impedance modulation circuit (3211), and the impedance modulation circuit (3211) has a control input (G) that applies a predetermined voltage to control the impedance, and the two wires (231, 321) whose output current-voltage characteristics can be changed by the voltage applied to the control input (G). The two wires (231, 321) and the impedance modulation circuit (3211) together form a loop path (231 → 3211 → 321).

[0086] The impedance modulation circuit (3211) changes the output current-voltage characteristic to a first output current-voltage characteristic and a second output current-voltage characteristic, respectively, in accordance with the binary control values ​​(221, 222) given to the control input (G), and operates within a predetermined current-voltage range enclosed by a first characteristic curve (CURH in FIG. 4) showing the first output current-voltage characteristic and a second characteristic curve (CURL in FIG. 4) showing the second output current-voltage characteristic.

[0087] When the impedance modulation circuit (3211) outputs the approximately constant current from the power supply (2300) to the path, the operating point (OPH, OPL in FIG. 4) of the impedance modulation circuit (3211) is determined as the intersection of the first characteristic curve (CURH in FIG. 4), the second characteristic curve (CURL in FIG. 4), and the straight line (ISUP in FIG. 4) indicating the magnitude of the approximately constant current.

[0088] The signal demodulation unit (230) has an impedance measurement unit (2330) that measures the impedance of the path (231, 321) based on the potential difference between both ends of the path (231, 321) when the approximately constant current is output from the power supply (2300) to the path, and a signal reproduction unit (2360) that reproduces the data value by comparing the measurement result by the impedance measurement unit (2330) with a predetermined threshold value (VRTH).

[0089] The predetermined threshold value (VRTH) is set to approximately the center (VRTH (223) in FIG. 5) of the range of values ​​that the impedance measurement result obtained by the impedance measurement unit (2330) can take.

[0090] As described above, according to the first embodiment, in the case of communication between devices in a cryogenic environment where power consumption constraints are significantly asymmetric, such as in a quantum computing system, only the minimum power consumption elements necessary to realize impedance modulation are arranged in the modulation side device, which has strict power consumption constraints, and the other elements are concentrated in the demodulation side device, which has a comparatively large margin in power consumption, thereby enabling remote impedance measurement. This makes it possible to realize a low-power consumption communication means in which the power consumption constraints are satisfied in both the modulation and demodulation side devices.

[0091] In addition, the modulation device has a reference control voltage input for adjusting the impedance modulation characteristics, and the demodulation device has a reference threshold voltage input for adjusting the data reproduction characteristics, including the voltage margin related to transmission between devices, providing a means for optimizing the power consumption required for data communication between devices in accordance with system requirements, which is expected to improve the practicality of the present invention and expand the range of its application. [Example]

[0092] Second Embodiment A quantum computing system 1A according to a second embodiment of the present invention will be described with reference to Fig. 6. The system configuration of the second embodiment is substantially the same as that of the first embodiment, and therefore a duplicated description will be omitted.

[0093] The configuration of the quantum computing system 1A differs from the configuration of the quantum computing system 1 shown in Fig. 1 in the following respects. That is, the signal demodulation unit 230 is replaced with a signal demodulation unit 240 that has a different communication path impedance measurement method and internal configuration. In addition, to reflect or clearly indicate the above-mentioned replacement, the reference numeral of the first control device 200 is changed to 200A, the reference numeral of the outbound communication means 231 is changed to 241, and the reference numeral of the output signal 232 is changed to 242. The other components are common to the quantum computing system 1.

[0094] 7 is a block diagram showing a detailed configuration of the signal demodulation unit 240. The signal demodulation unit 240 includes a constant voltage source 2420, a current input impedance measurement unit 2440, and a signal reproduction unit 2460.

[0095] The constant voltage source 2420 is a power supply circuit that outputs an approximately constant voltage, which is required to measure the total impedance of the communication path formed by the outbound communication means 241, the signal modulation unit 320, and the return communication means 321, and which has a value fixed at the time of design or a value that can be changed by a procedure not shown, and its voltage output is connected to the outbound communication means 241.

[0096] The output voltage value of the constant voltage source 2420 can be selected so that the drain terminal-source terminal voltage (VDS) in the impedance modulation circuit 3211 in the signal modulation unit 320 during impedance modulation operation is the minimum necessary voltage change, for example, 300 mV, taking into consideration the balance between the signal-to-noise ratio requirements required for the communication path and the power consumption of the impedance modulation circuit 3211 itself, thereby reducing unnecessary power consumption.

[0097] The current input impedance measuring section 2440 is functionally equivalent to a differential amplifier circuit having a current-voltage conversion function and a fixed gain G. The current input impedance measuring section 2440 is composed of a current detection circuit 2441 and a differential amplifier circuit 2442.

[0098] The current detection circuit 2441 is typically a resistive element having a fixed resistance value R, and converts the current value of the current flowing through the communication path into a voltage value (=current value×R). The differential amplifier circuit 2442 is common to the differential amplifier circuit 2331 having a fixed gain G, and amplifies the potential difference between both ends of the current detection circuit 2441 by G times.

[0099] The amplified voltage is output as an amplified signal 2443. Here, the fixed gain G may be selected so that the amplified signal 2443 is equal to or lower than the power supply voltage of the first control device 200A and equal to or lower than the maximum input voltage allowed by the signal regeneration unit 2460.

[0100] The signal regeneration unit 2460 is a comparison circuit 2461 that determines the magnitude relationship between two positive and negative voltage inputs, and outputs a voltage representing 0 or L in binary representation if the voltage value of the amplified signal 2443 is smaller than the voltage value of the reference threshold voltage 223, and 1 or H if not.

[0101] The output of the comparison circuit 2461 connected to the output signal 242 corresponds to the output value of the functional unit output signal 311, which is reproduced based on the total impedance measurement result of the communication path. Note that a method for selecting a voltage value to be set as the reference threshold voltage 223 will be described later.

[0102] Whether the amplified signal 2443 and the reference threshold voltage 223 should be connected to the positive or negative input of the comparison circuit 2461 depends on the impedance characteristics of the impedance modulation circuit 3211. That is, when the magnitude relationship between the voltage values ​​of the functional unit output signal 311 and the magnitude relationship between the potential difference generated at both ends of the current detection circuit 2441 are reversed, the amplified signal 2443 is connected to the negative side of the comparison circuit 2461, and when this is not the case, the amplified signal 2443 is connected to the positive side, thereby enabling the intended signal reproduction operation.

[0103] 8 is a diagram showing the characteristics and operating points of the impedance modulation circuit 3211 according to the second embodiment. The drain-source current-voltage (IDS-VDS) characteristics and operating point of the impedance modulation circuit 3211 change as follows according to the gate-source voltage (VGS) applied by the modulation signal 3205:

[0104] (1) When the functional unit output signal 311 (DOUT) is 1 or H, the voltage value of VGS becomes approximately equal to the voltage value of the H-side reference control voltage 221 (VGSH), resulting in the impedance characteristics shown by the curve CURH. At this time, the intersection OPH with the line VSUP, which corresponds to the current-voltage characteristics of the communication path, becomes the operating point, and the vertical axis (IDS) component represents the current value (IDSH) flowing through the communication path.

[0105] (2) When the functional unit output signal 311 (DOUT) is 0 or L, the voltage value of VGS becomes approximately equal to the voltage value of the L-side reference control voltage 222 (VGSL), resulting in the impedance characteristics shown by the curve CURL. At this time, the intersection OPL with the line VSUP, which corresponds to the current-voltage characteristics of the communication path, becomes the operating point, and the vertical axis (IDS) component is the current value (IDSL) flowing through the communication path.

[0106] Here, R is the resistance value of the current detection circuit 2441, and OFST is proportional to the current value flowing through the communication path, and corresponds to the voltage drop due to the sum of the transmission impedances of the outbound communication means 231 and the inbound communication means 321.

[0107] Suppressing the current value flowing through the communication path in order to reduce fluctuations in the voltage value of VDS is an effective way to reduce the power consumption of the impedance modulation circuit 3211. However, in an actual system, the curves CURH and CURL and the straight line VSUP have widths that correspond to characteristics variations due to manufacturing of the impedance modulation circuit 3211, characteristics variations due to fluctuations in the ambient temperature during operation, and the stability of the output voltage of the constant voltage source 2420, and it is necessary to take into account that the intersections OPH and OPL, which correspond to the operating points, also fluctuate within a specific current / voltage range.

[0108] In order to enable the signal demodulation unit 240 to distinguish the current values ​​(IDSH and IDSL) of IDS at the two operating points, it is advisable to select the output voltage of the constant voltage source 2420 on the condition that the specific current-voltage ranges related to the intersections OPH and OPL do not overlap and are separated by at least a predetermined current margin required by the system.

[0109] 9 is a timing chart showing, from an overview, the operation of impedance modulation data communication realized between the signal modulation unit 320 and the signal demodulation unit 240 in Example 2. As an example, it shows that the time-series data (consecutive values ​​1 and 0) output by the function unit 310 is correctly reproduced by the signal reproduction unit 2460.

[0110] Via the functional unit output signal 311, the signal modulation unit 320 that has received the data to be output by the functional unit 310 performs an impedance modulation operation based on the data value (1(H) or 0(L)). As a result of the modulation operation, a current having a current value of IDSH or IDSL flows through the communication path.

[0111] The termination on the signal demodulation unit 240 side of the demultiplexing communication means 321 is grounded internally via the current detection circuit 2441. The potential difference across both ends of the current detection circuit 2441, that is, the result of converting from the current value flowing through the communication path to a voltage value (IDSH×R or IDSL×R) is input to the differential amplification circuit 2442. The differential amplification circuit 2442 having a fixed gain G outputs a signal having a voltage value of IDSH×R×G or IDSL×R×G as the amplified signal 2443.

[0112] The amplified signal 2443 is connected to the positive input of the comparison circuit 2461, and the magnitude of the voltage value is compared with the reference threshold voltage 223 connected to the negative input. When the former is larger, the data value 1(H) is output as the comparison result to the output signal 242, and when it is not, the data value 0(L) is output.

[0113] In the connection form to the comparison circuit 2461 described above, a correct comparison result can be obtained only when the impedance modulation circuit 3211 has a modulation characteristic satisfying IDSH>IDSL. When the modulation characteristic becomes IDSH<IDSL, it is advisable to swap the connections of the positive input and the negative input of the comparison circuit 2461.

[0114] The voltage value of the reference threshold voltage 223 is preferably selected to be a value near the center of the voltage fluctuation range of the amplified signal 2443 and can be determined experimentally after the construction of the quantum computing system ......

[0115] Compared to Example 1, Example 2 differs in its configuration based on the impedance measurement method. The effects and scope of application of the method to device-to-device communication are the same, and a more suitable method may be selected depending on the system requirements and ease of design. [Example]

[0116] A quantum computing system 1B according to a third embodiment of the present invention will be described with reference to Fig. 10. The system configuration of the third embodiment is substantially the same as that of the first embodiment, and therefore, overlapping descriptions will be omitted.

[0117] 1, the configuration of the quantum processing system 1B differs in the following respects: That is, the outbound communication means 231 (OUTWARD) is divided into two, that is, outbound communication means 1 251-1 (OUTWARD1) and outbound communication means 251-2 (OUTWARD2), and the return communication means 321 (RETURN) is divided into two, that is, return communication means 1 331-1 (RETURN1) and return communication means 2 331-2 (RETURN2), thereby duplexing the communication paths, and in addition, in order to accommodate the duplexing of the communication paths, the signal demodulation unit 230 is replaced with a signal demodulation unit 250, and the signal modulation unit 320 is replaced with a signal modulation unit 330.

[0118] Furthermore, to reflect or clarify the above-mentioned substitution, the reference numerals of the first control device 200, the second control device 300, and the output signal 232 are changed to 200B, 300B, and 252, respectively. The other components are common to the quantum computing system 1.

[0119] 11 is a block diagram showing a detailed configuration of the signal modulation unit 330. The signal modulation unit 330 is configured to include modulation signal generation units 3300-1 and 3300-2 that have a common internal configuration and operation, and impedance modulation units 3310-1 and 3310-2 that have substantially the same impedance modulation characteristics.

[0120] The modulation signal generation unit 3300-1 (or 3300-2) is functionally equivalent to a two-input, one-output analog multiplexer circuit. The modulation signal generation unit 3300-1 (or 3300-2) is composed of switch circuits 3301 and 3302 that are both turned on when the state of the control input is 1 or H, and an inversion circuit 3303 that inverts the logical state. In addition, as an internal signal, it has a functional unit output inverted signal 3304 in which the logical state of the functional unit output signal 311 is inverted by the inversion circuit 3303.

[0121] When the state of the functional unit output signal 311 is 1 or H (i.e., when the functional unit output inversion signal 3304 is 0 or L), the switch circuit 3301 is on and the switch circuit 3302 is off, and the voltage applied to the H-side reference control voltage 221 is output to the impedance modulation unit 3310-1 (or 3310-2) as modulation signal 3305-1 (or 3305-2).

[0122] When the state of the functional unit output signal 311 is 0 or L (i.e., when the functional unit output inverted signal 3304 is 1 or H), the switch circuit 3301 is off and the switch circuit 3302 is on, and the voltage applied to the L-side reference control voltage 222 is output to the impedance modulation unit 3310-1 (or 3310-2) as the modulation signal 3305-1 (or 3305-2). In other words, the voltage value of the modulation signal 3305-1 (or 3305-2) takes one of two values ​​depending on the state of the functional unit output signal 311.

[0123] The impedance modulation unit 3310-1 (or 3310-2) is an impedance modulation circuit 3311 whose impedance characteristics are variable according to the voltage value applied to a control input, and one implementation form thereof is an N-channel field effect transistor operating in enhancement mode, similar to the impedance modulation unit 3210. Note that a gate terminal, a source terminal, and a drain terminal indicated by symbols G, S, and D are connected to the modulation signal 3305-1 (or 3305-2), the outgoing path 1 communication means 251-1 (or the outgoing path 2 communication means 251-2), and the return path 1 communication means 331-1 (or the return path 2 communication means 331-2), respectively.

[0124] The impedance characteristics of the impedance modulation circuit 3311, i.e., the current-voltage (IDS-VDS) characteristics between the drain terminal and the source terminal, correspond to the binary voltage values ​​input from the modulation signal 3305-1 (or 3305-2), and are one of two curves statically determined from the voltage applied between the gate terminal and the source terminal.

[0125] Since the transmission impedance of the outbound path 1 communication means 251-1 (or the outbound path 2 communication means 251-2) and the return path 1 communication means 331-1 (or the return path 2 communication means 331-2) is usually a fixed value, for each of the duplicated communication paths, the total impedance value of the communication path, which is the sum of the transmission impedances of the outbound path 1 communication means 251-1 and the return path 1 communication means 331-1 and the impedance of the impedance modulation unit 3310-1 (or the sum of the transmission impedances of the outbound path 2 communication means 251-2 and the return path 2 communication means 331-2 and the impedance modulation unit 3310-2), is measured according to a predetermined procedure described below.

[0126] This allows the output state of the functional unit output signal 311 to be reproduced as a substantially instantaneous value on the signal demodulation unit 250 side without introducing a complex communication protocol that increases power consumption and time fluctuations.

[0127] 12 is a block diagram showing a detailed configuration of the signal demodulation unit 250. The signal demodulation unit 250 includes a constant current source 2510 with a current mirror function, a differential voltage input impedance measurement unit 2550, and a signal regeneration unit 2560.

[0128] The constant current source 2510 with current mirror function is a power supply circuit that outputs two systems of approximately constant current, which is required for measuring the total impedance of the duplicated communication path, and has a value fixed at the time of design or a value that can be changed by a procedure not shown, and its current output is connected to the outbound path 1 communication means 251-1 and the outbound path 2 communication means 252-2.

[0129] The output current value of the constant current source 2510 with current mirror function to each system can be reduced by selecting the minimum necessary voltage change, for example, 300 mV, in consideration of the balance between the signal-to-source terminal voltage (VDS) in the impedance modulation circuit 3311 during impedance modulation operation and the power consumption of the impedance modulation circuit 3211 itself, taking into account the signal-to-noise ratio requirement required for the communication path. Note that the function of the constant current source 2510 with current mirror function is to output currents with approximately the same current value to each system.

[0130] The differential voltage input impedance measurement unit 2550 has a function of measuring the total impedance of each duplicated communication path and calculating the difference between the measurement results. The differential amplifier circuit 2551 has a fixed gain G, amplifies the differential voltage between the outbound path 1 communication means 251-1 and the return path 1 communication means 331-1 (grounded within the signal demodulation unit 250) by G times, and outputs the amplified voltage as an amplified signal 2553. The differential amplifier circuit 2552 has a fixed gain G, amplifies the differential voltage between the outbound path 2 communication means 251-2 and the return path 2 communication means 331-2 (grounded within the signal demodulation unit 250) by G times, and outputs the amplified voltage as an amplified signal 2554.

[0131] Differential amplifier circuit 2555 has a fixed gain of 1, and outputs a differential voltage between amplified signal 2553 and amplified signal 2554 as differential signal 2556. Here, the fixed gain G may be selected so as to satisfy the following: both amplified signal 2553 and amplified signal 2554 are within the voltage range of the positive and negative power supplies of the first control device 200B and the input voltage range allowed by the differential amplifier circuit 2555; and further, the differential signal 2556 is within the voltage range of the positive and negative power supplies of the first control device 200B and the input voltage range allowed by the signal regeneration unit 2560.

[0132] The signal regeneration unit 2560 is a comparison circuit 2561 itself that determines the magnitude relationship between two positive and negative voltage inputs, and outputs a binary representation of 1 or H if the voltage value of the differential signal 2556 is smaller than the voltage value of the reference threshold voltage 223, and outputs a voltage indicating 0 or L if not. The output of the comparison circuit 2561 connected to the output signal 252 corresponds to the output value of the functional unit output signal 311 regenerated based on the total impedance measurement result of the duplicated communication path. A method for selecting the voltage value to be set as the reference threshold voltage 223 will be described later.

[0133] Whether the differential signal 2556 and the reference threshold voltage 223 should be connected to the positive or negative input of the comparator circuit 2561 depends on the impedance characteristics of the impedance modulation circuit 3311 .

[0134] In other words, if the magnitude relationship between the voltage values ​​of the functional unit output signal 311 and the magnitude relationship between the potential difference generated by the impedance modulation circuit 3311 (the difference between the voltage values ​​of the outbound path 1 communication means 251-1 and the return path 1 communication means 331-1, and the same applies to the outbound path 2 communication means 251-2 and the return path 2 communication means 331-2) is reversed, the differential signal 2556 is connected to the negative side of the comparison circuit 2561, and if not, to the positive side, thereby enabling the intended signal regeneration operation.

[0135] 13 is a timing chart showing, from an overview, the operation of impedance modulation data communication realized between the signal modulation unit 330 and the signal demodulation unit 250 in Example 3. As an example, it shows that the time-series data (consecutive values ​​1 and 0) output by the function unit 310 is correctly reproduced by the signal reproduction unit 2560.

[0136] The signal conversion unit 330, which has received the data to be output by the functional unit 310 via the functional unit output signal 311, performs an impedance modulation operation based on the data value (1 (H) or 0 (L)). As a result of the modulation operation, a VDSH or VDSL potential difference is generated between the terminal of the outgoing path 1 communication means 251-1 on the signal modulation unit 330 side and the terminal of the incoming path 1 communication means 331-1 on the signal modulation unit 330 side. The same applies to the outgoing path 2 communication means 251-2 and the incoming path 2 communication means 331-2.

[0137] An end of the signal demodulation unit 250 side of the return path 1 communication means 331-1 is grounded internally and connected to the negative input of the differential amplifier circuit 2551, and a voltage having a value obtained by superimposing a first offset (OFST1) on VDSH or VDSL is applied between the return path 1 communication means 331-1 and the outgoing path 1 communication means 251-1 connected to the positive input. Also, an end of the signal demodulation unit 250 side of the return path 2 communication means 331-2 is grounded internally and connected to the positive input of the differential amplifier circuit 2552, and a voltage having a value obtained by superimposing a second offset (OFST2) on VDSH or VDSL is applied in the negative direction between the return path 2 communication means 331-2 and the outgoing path 2 communication means 251-2 connected to the negative input.

[0138] The first offset (OFST1) corresponds to the voltage drop due to the sum of the transmission impedances of the forward path 1 communication means 251-1 and the reverse path 1 communication means 331-1, and the second offset (OFST2) corresponds to the voltage drop due to the sum of the transmission impedances of the forward path 2 communication means 251-2 and the reverse path 2 communication means 331-2. Excluding variations caused by the environmental temperature gradient of the transmission cable, it is generally a substantially fixed value that does not depend on the data value. However, it should be noted that OFST1 and OFST2 do not necessarily match due to reasons such as differences in the wire material and wiring length of the transmission cable.

[0139] From the signals amplified by G times by the differential amplifier circuits 2551 and 2552 respectively, the differential amplifier circuit 2555 takes the difference, and as the amplified signal 2556, outputs a signal having a voltage value of (2×VDSH + OFST1 + OFST2)×G or (2×VDSL + OFST1 + OFST2)×G.

[0140] The amplified signal 2556 is connected to the negative input of the comparison circuit 2561, and the magnitude of the voltage value is compared with the reference threshold voltage 223 connected to the positive input. When the former is smaller, the data value 1 (H) is output as the comparison result to the output signal 252, and when it is not, the data value 0 (L) is output.

[0141] In the connection form to the comparison circuit 2561 described above, a correct comparison result can be obtained only when the impedance modulation circuit 3311 has a modulation characteristic that satisfies VDSH < VDSL. When the modulation characteristic becomes VDSH > VDSL, it is advisable to swap the connections of the positive input and the negative input of the comparison circuit 2561.

[0142] Also, the voltage value of the reference threshold voltage 223 may be selected to be a value near the center of the voltage fluctuation range of the amplified signal 2556, and it can be determined experimentally after the construction of the quantum computing system 1C.

[0143] Compared to the form of the above-mentioned Example 1, in Example 3, the communication paths are duplicated, which increases the number of elements that can be added and adjusted in the system construction phase, such as the selection of wire materials and routing of the transmission cables used for each communication path. The robustness of this communication method is improved by providing a means for statically or dynamically correcting the modulation characteristics of the impedance modulation circuit, which are determined at the time of semiconductor chip manufacturing, by adjusting the combination of transmission cables and the reference threshold voltage. [Example]

[0144] A quantum computing system 1C according to the fourth embodiment will be described with reference to Fig. 14. The system configuration of the fourth embodiment is substantially the same as that of the first embodiment, and therefore, a duplicated description will be omitted.

[0145] 1 , the configuration of the quantum processing system 1C differs in the following respects: That is, in order to realize control coordination and synchronous communication between the first control device and the second control device, the functional unit 310 is replaced with a functional unit 340 that can receive a control signal including a predetermined timing signal via a functional unit control means 281, the signal demodulation unit 230 is replaced with a signal demodulation unit 260 that can input a predetermined control signal via a signal demodulation unit control means 282, and a sequence control unit 280 that generates the functional unit control means 281 and the signal demodulation unit control means 282, and a communication means 102 that sends the control instruction information from the system control device 100 to the sequence control unit 280 are added.

[0146] In this embodiment, the output signal 231 output from the signal demodulation unit 230 is used as a trigger input signal 262 from the signal demodulation unit 260 to the sequence control unit 280. In addition, in order to reflect or clarify the above-mentioned substitution, the reference numeral of the first control device 200 is changed to 200C, the reference numeral of the outbound communication means 231 is changed to 261, the reference numeral of the second control device 300 is changed to 300C, and the reference numeral of the functional unit output signal 311 is changed to 341. The other components are common to those of the quantum operation system 1.

[0147] 15 is a block diagram showing a detailed configuration of the sequence control unit 280. The sequence control unit 280 includes a communication interface unit 2800, a control sequence table 2810, and a control signal generation unit 2820.

[0148] The communication interface unit 2800 controls communication with the system control device 100 connected via the communication means 102, and converts various control signals between an internal communication means 2801 that controls access to the control signal generation unit 2810 and an internal communication means 2802 that controls access to the control sequence table 2820.

[0149] It is assumed that the sequence table 2820 pre-stores one or more command sequences that define the operations to be performed by the sequence control unit 280, which are at least part of the control instruction information from the system control device 100 via the communication means 102 and the internal communication means 2802.

[0150] Based on an instruction from the system control device 100 via the communication means 102 and the internal communication means 2801, the control signal generation unit 2810 starts command processing starting from the beginning of the command string or a specified position.

[0151] The control signal generation unit 2810 first reads information specifying the entry in which the command to be executed first is stored, outputs it to entry information 2811, and requests the control sequence table 2820 to read control information required for processing the command. Upon receiving the request, the control sequence table 2820 reads control information related to the command from the specified entry, and outputs it to the control signal generation unit 2810 as sequence control information 2821.

[0152] The control signal generation unit 2810, which has acquired the control information linked to the specified command via the sequence control information 2821, performs a control operation specific to the command based on the interpretation of the control information. Note that the following explanation is about a command set defined as an example assuming control cooperation between devices, and does not prevent some commands from being deleted from the command set or new commands such as data transfer from being added to the command set.

[0153] FCONFIG command: A command for transmitting functional configuration information of the functional unit 340, and control information regarding the specified functional configuration is output together with the command to the functional unit control means 281. When the output of the control information is complete, the contents of the read entry information 2811 are updated and the subsequent command is processed. Meanwhile, the functional unit 340 that has received the control signal temporarily stores the received control signal in an internal storage means.

[0154] FUPDATE command: This is a command that instructs the functional unit 340 to reflect control information temporarily stored in the storage means inside the functional unit 340, and outputs a predetermined timing signal that can identify this command to the functional unit control means 281. When the output of the timing signal is complete, the contents of the read entry information 2811 are updated and subsequent commands are processed. Meanwhile, the functional unit 340 that has received the timing signal updates the configuration state of the functional unit 340 based on the temporarily stored control information.

[0155] FSTART command: This is a command requesting the functional unit 340 to start operating, and a predetermined timing signal that can be identified as this command is output to the functional unit control means 281. When the output of the timing signal is completed, the contents of the read entry information 2811 are updated and the subsequent command is processed. Meanwhile, when the functional unit 340 receives the timing signal, if it is in an inactive state at the time of reception, it transitions to an active state and starts executing predetermined processing according to the configuration, and if it is in an active state at the time of reception, it continues the processing that is currently being executed.

[0156] FSTOP command: This is a command that requests the functional unit 340 to stop operating, and a predetermined timing signal that can identify this command is output to the functional unit control means 281. When the output of the timing signal is complete, the contents of the read entry information 2811 are updated and the subsequent command is processed. On the other hand, when the functional unit 340 receives the timing signal, if it is in an operating state at the time of reception, it stops the processing it is currently performing and then transitions to an inactive state, and if it is in an inactive state at the time of reception, it does nothing.

[0157] WAIT command: When the trigger input signal 262 indicates a negated state, the operation of the control signal generator 2810 is temporarily stopped until the trigger input signal 262 transitions to an asserted state, and the subsequent command is processed after the transition to the asserted state. When the trigger input signal 262 indicates an asserted state, nothing is done.

[0158] END command: A command to stop the operation of the control signal generation unit 2810, and updates the contents of the read entry information 2811 to point to the command following this command, but does not process the sequence control information 2821 obtained from the control sequence table 2820.

[0159] COM_ON command: A predetermined signal that enables the operation of the signal demodulation unit 260 is output to the signal demodulation unit control means 282. When the output of the signal is completed, the contents of the read entry information 2811 are updated and subsequent commands are processed. Specific operations on the signal demodulation unit 260 side will be described later.

[0160] COM_OFF command: A predetermined signal for disabling the operation of the signal demodulation unit 260 is output to the signal demodulation unit control means 282. When the output of the signal is completed, the contents of the read entry information 2811 are updated and subsequent commands are processed. The specific operation on the signal demodulation unit 260 side will be described later.

[0161] 16 is a block diagram showing a detailed configuration of the signal demodulation unit 260. The signal demodulation unit 260 includes a constant current source 2600 with an operation enable input, a voltage input impedance measurement unit 2630 with an operation enable input, a signal regeneration unit 2660 with an operation enable input, and a signal demodulation control unit 2670.

[0162] The constant current source 2600 with operation enable input is substantially the same as the constant current source 2300, and differs functionally in that its operation state can be enabled or disabled based on an instruction from operation control means 2671. More specifically, when the request indicates that the operation of the signal demodulation unit 260 is enabled, the same current as the output of the constant current source 2300 is output as the outgoing communication means 261, and when the request indicates that the operation is disabled, the operation of the constant current source 2600 with operation enable input itself and / or the output of the outgoing communication means 261 is stopped.

[0163] The voltage impedance measurement unit 2630 with operation enable input is substantially the same as the voltage input impedance measurement unit 2330 (the operation of the differential amplifier circuit 2631 is the same as that of the differential amplifier circuit 2331), and differs functionally in that its operation state can be enabled or disabled based on an instruction from operation control means 2672. More specifically, if the request indicates that the signal demodulation unit 260 should be enabled, it outputs the same signal as the output of the voltage impedance measurement unit 2330 as an amplified signal 2632, and if the request indicates that it should be disabled, it stops the operation of the voltage impedance measurement unit 2630 with operation enable input itself and / or the output of the amplified signal 2632.

[0164] The signal regenerator 2660 with operation enable input is substantially the same as the signal regenerator 2360 (the operation of the comparator circuit 2661 is the same as that of the comparator circuit 2361), and differs functionally in that its operation state can be enabled or disabled based on an instruction from operation control means 2673. More specifically, if the request indicates that the operation of the signal demodulator 260 is to be enabled, it outputs the same signal as the output of the signal regenerator 2360 as the trigger input signal 262, and if the request indicates that it is to be disabled, it stops the operation of the signal regenerator 2660 itself and / or the output of the trigger input signal 262.

[0165] The signal demodulation control unit 2670 manages the operation state of the signal demodulation unit 260 in accordance with the request content output from the signal demodulation unit control means 282 when the sequence control unit 280 processes a COM_ON or COM_OFF command. If the operation state is an enable state, it operates the constant current source 2600 with operation enable input, the voltage impedance measurement unit 2630 with operation enable input, and the signal regeneration unit 2660 with operation enable input via the operation control means 2671, 2672, and 2673, and stops their operation if the operation state is a disable state.

[0166] By including a command that controls the operating state of the signal demodulation unit 260 in the command set supported by the sequence control unit 280, the operating state of the signal demodulation unit 260 can be enabled in a limited manner in synchronization with the timing at which inter-device communication occurs during the processing of a specific control sequence, thereby reducing average power consumption.

[0167] 17 shows an example of settings in the control sequence table 2820. The control sequence table 2820 is made up of a plurality of entries each identifiable by an entry number, and each entry can store control information for one command (a combination of information identifying the command and processing parameters for that command) from among the commands included in the command set that the sequence control unit 280 can process.

[0168] When the control sequence table 2820 receives a control information read request from the control signal generation unit 2810 via the read entry information 2811, it reads control information from the entry corresponding to the entry number included in the read entry information 2811 and outputs the control information to the control signal generation unit 2810 as the sequence control information 2821.

[0169] FIG. 18 is a time chart that outlines the procedure for executing inter-device communication in synchronization with control sequence processing based on the settings of the control sequence table 2820 illustrated in FIG. 17 in the quantum computing system 1C according to the fourth embodiment.

[0170] The entire control sequence is made up of eight consecutive commands. Prior to the start of processing of the control sequence, the contents of the control sequence table 2820 are set by the system control application running on the system control device 100 via the communication means 102 and the internal communication means 2802.

[0171] When the setting is completed, the system control device 100 instructs the control signal generation unit 2810 to start execution from entry 0 corresponding to the beginning of the control sequence via the communication means 102 and the internal communication means 2801. Upon receiving the instruction, the control signal generation unit 2810 transitions the operation state from a stopped state to an executing state, and requests, via the read entry information 2811, reading of the control information stored in entry 0 of the control sequence table 2820. Upon receiving the request, the sequence table 2820 outputs the control information as the sequence control information 2821.

[0172] The control signal generation unit 2810, which has interpreted the sequence control information 2821 as indicating an FCONFIG command, extracts control information (configuration information) relating to the functional configuration of the functional unit 340 as part of the received control information, and outputs the configuration information to the functional unit control means 281. The functional unit 340, which has received the configuration information, temporarily stores the configuration information in an internal storage means. Meanwhile, it outputs a predetermined signal (NOP) indicating that there is no instruction to the signal demodulation unit control means 282. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts command processing of entry 1.

[0173] The control signal generation unit 2810, which interprets the control information read from entry 1 of the control sequence table 2820 as indicating an FUPDATE command, outputs a predetermined signal to the function unit control means 281, instructing the function unit 340 to reflect the configuration information temporarily stored in the function unit 340. Upon receiving the predetermined signal, the function unit 340 updates its function based on the control information temporarily stored in its internal storage means. On the other hand, it outputs a predetermined signal (NOP) indicating no instruction to the signal demodulation unit control means 282. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts processing the command of entry 2.

[0174] The control signal generation unit 2810, which interprets the control information read from entry 2 of the control sequence table 2820 as indicating a COM_ON command, outputs a predetermined signal requesting the signal demodulation unit 260 to be enabled, to the signal demodulation unit control means 282. Upon receiving the predetermined signal, the signal demodulation control unit 2670 transitions the operation state of the signal demodulation unit 260 to an enabled state and starts operation of each unit via the operation control means 2671, 2672, and 2673. On the other hand, it outputs a predetermined signal (NOP) indicating that there is no instruction to the function unit control means 281. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts processing the command of entry 3.

[0175] The control signal generation unit 2810, which interprets the control information read from entry 3 of the control sequence table 2820 as indicating an FSTART command, outputs a predetermined timing signal to the function unit control means 281 to instruct the function unit 340 to start operating. Upon receiving the predetermined timing signal, the function unit 340 transitions from a non-operating state to an operating state and begins executing predetermined processing according to the configuration. On the other hand, it outputs a predetermined signal (NOP) to the signal demodulation unit control means 282 indicating that there is no instruction. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts processing the command of entry 4.

[0176] The control signal generation unit 2810, which has interpreted the control information read from entry 4 of the control sequence table 2820 as indicating a WAIT command, transitions the operating state from an execution state to a wait state and suspends operation until the trigger input signal 262 indicates an asserted state. It outputs a predetermined signal (NOP) to both the function unit control means 281 and the signal demodulation unit control means 282, indicating that no instruction has been given.

[0177] If the trigger input signal 262 is in an asserted state at the time of processing the command, or if the operation state of the control signal generation unit 281 is in a wait state and then the trigger input signal 262 transitions from a negated state to an asserted state, the control signal generation unit 2810 maintains the operation state in an execution state or transitions the operation state from the wait state to the execution state, then increments the entry number and starts processing the command of entry 5.

[0178] The control signal generation unit 2810, which interprets the control information read from entry 5 of the control sequence table 2820 as indicating an FSTOP command, outputs a predetermined timing signal to the functional unit control means 281 to instruct the functional unit 340 to stop operating. Upon receiving the predetermined timing signal, the functional unit 340 transitions from an operating state to a non-operating state, fixes the functional unit output signal 341 to a predetermined state, and stops operating. On the other hand, it outputs a predetermined signal (NOP) indicating that there is no instruction to the signal demodulation unit control means 282. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts processing the command of entry 6.

[0179] The control signal generation unit 2810, which interprets the control information read from entry 6 of the control sequence table 2820 as indicating a COM_OFF command, outputs a predetermined signal to the signal demodulation unit control means 282 requesting disabling of the operation of the signal demodulation unit 260. The signal demodulation control unit 2670, which has received the predetermined signal, transitions the operation state of the signal demodulation unit 260 to a disabled state and stops the operation of each unit via the operation control means 2671, 2672, and 2673. On the other hand, it outputs a predetermined signal (NOP) indicating that there is no instruction to the function unit control means 281. When processing of the command is completed, the control signal generation unit 2810 increments the entry number and starts processing the command of entry 7.

[0180] The control signal generation unit 2810, which interprets the control information read from entry 7 of the control sequence table 2820 as indicating an END command, transitions the operating state from the execution state to the stop state. It outputs a predetermined signal (NOP) indicating no instruction to both the function unit control means 281 and the signal demodulation unit control means 282. When processing of the command is completed, the control signal generation unit 2810 increments the entry number but does not process commands in subsequent entries, and waits for a new request to be sent from the system control device 100.

[0181] Compared with the above-described embodiment 1, in embodiment 4, the operation of the functional unit 340, the output timing of desired data for the functional unit output signal 341, the timing at which data on the communication path connecting the signal modulation unit 330 and the signal demodulation unit 260 becomes valid, and the timing at which valid reproduced data is output from the signal demodulation unit 260 can be managed in a unified manner in synchronization with the processing by the control signal generation unit 2810 regarding the command sequence stored in the control sequence table 2820, thereby further significantly improving the practicality of the present invention.

[0182] According to the above embodiment, it is possible to provide a low-power consumption communication means required for high-speed control of quantum operations, which is particularly applicable to devices in cryogenic environments where power consumption constraints are significantly asymmetric.

[0183] Furthermore, according to the above embodiment, it is not necessary to provide a driver circuit or a resistive element for data communication in the second control device, and data communication via long-distance wiring can be realized with low power consumption, which contributes to achieving the power consumption constraints in the second control device.

[0184] Furthermore, according to the above embodiment, it becomes possible to realize a quantum computer of a practical scale, which will consume less energy, reduce carbon emissions, prevent global warming, and contribute to the realization of a sustainable society.

[0185] Although the embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0186] The components described in the embodiments may be realized by dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or by programmable hardware such as an FPGA (Field-Programmable Gate Array).Furthermore, at least some of the functions may be realized by a system control application running on a system control device.

[0187] Furthermore, in the above embodiment, a quantum computer has been used as an example for explanation, but the present invention is not limited to quantum computers and can also be applied to communication with devices with strict power consumption restrictions, such as sensor devices. [Explanation of symbols]

[0188] 1, 1A, 1B, 1C, 10: Quantum computing system 100: System control device 200, 200A, 200B, 200C: First control device 210: Operation setting section 220: Voltage generation unit 230, 240, 250, 260: Signal demodulation section 280: Sequence control unit 300, 300B, 300C: Second control device 310, 340: Functional section 320, 330: signal modulation section 2300: Constant current source 2330: Voltage input impedance measurement unit 2331, 2442: Differential amplifier circuit 2332, 2443: Amplified signal 2360, 2460, 2560: Signal regeneration section 2361, 2461, 2561: Comparison circuit 2420: Constant voltage source 2440: Current input impedance measurement unit 2441: Current detection circuit 2510: Constant current source with current mirror function 2550: Differential voltage input impedance measurement unit 2551, 2552, 2555: Differential amplifier circuit 2600: Constant current source with operation enable input 2630: Voltage input impedance measurement unit with operation enable input 2631: Differential amplifier circuit 2660: Signal regeneration unit with operation enable input 2661: Comparison circuit 2670: Signal demodulation control section 2800: Communication interface section 2810: Control signal generation unit 2820: Control sequence table 3200, 3300-1, 3300-2: Modulation signal generator 3201, 3202, 3301, 3302: Switch circuits 3203, 3303: Inverter circuit 3210, 3310-1, 3310-2: Impedance modulation section 3211, 3311: Impedance modulation circuit

Claims

1. A semiconductor device having a first control device and a second control device, and performing data communication between the first control device and the second control device, a path including at least two wires arranged between the first control device and the second control device, through which currents flow in opposite directions to each other; The second control device a signal modulation unit that receives an input of a binary control value and selects one of the binary control values ​​based on a data value to be output to the first control device, thereby changing the impedance of the path; The first control device a power source that outputs a substantially constant current or a substantially constant voltage to the path; a signal demodulator for recovering the data value from the impedance of the path; A semiconductor device comprising:

2. The signal modulation unit an impedance modulation circuit; The impedance modulation circuit a control input for applying a predetermined voltage to control the impedance; and the two wirings whose output current-voltage characteristics can be changed by the voltage applied to the control input; 2. The semiconductor device according to claim 1, wherein the two wirings and the impedance modulation circuit together form a loop path.

3. The impedance modulation circuit changing the output current-voltage characteristic to a first output current-voltage characteristic and a second output current-voltage characteristic in accordance with the binary control value applied to the control input; 3. The semiconductor device according to claim 2, wherein the semiconductor device operates within a predetermined current-voltage range encompassed by a first characteristic curve showing the first output current-voltage characteristic and a second characteristic curve showing the second output current-voltage characteristic.

4. The impedance modulation circuit 4. The semiconductor device according to claim 3, wherein, when the approximately constant current is output from the power supply to the path, the operating point of the impedance modulation circuit is determined as the intersection of the first characteristic curve, the second characteristic curve, and a straight line indicating the magnitude of the approximately constant current.

5. The impedance modulation circuit 4. The semiconductor device according to claim 3, wherein, when the power supply outputs the approximately constant voltage to the path, the operating point of the impedance modulation circuit is determined as the intersection of the first characteristic curve, the second characteristic curve, and a straight line indicating the current-voltage characteristics to be satisfied by the impedance modulation circuit, which is obtained by subtracting the impedances of the two wirings from the total impedance of the path.

6. The signal demodulation unit an impedance measurement unit that measures the impedance of the path based on a potential difference between both ends of the path when the substantially constant current is output from the power supply to the path; a signal regenerating unit that regenerates the data value by comparing the measurement result by the impedance measuring unit with a predetermined threshold value; 2. The semiconductor device according to claim 1, further comprising:

7. The signal demodulation unit an impedance measurement unit that measures the impedance of the path based on a current value flowing through the path when the approximately constant voltage is output from the power supply to the path; a signal regenerating unit that regenerates the data value by comparing the measurement result by the impedance measuring unit with a predetermined threshold value; 2. The semiconductor device according to claim 1, further comprising:

8. The predetermined threshold value is 8. The semiconductor device according to claim 7, wherein the impedance measurement result by the impedance measurement unit is set to be approximately in the center of a range of possible values.

9. 3. The semiconductor device according to claim 2, wherein a plurality of the loop-shaped paths are arranged in parallel to each other, thereby multiplexing the paths.

10. The first control device A sequence control unit is provided. The sequence control unit Holds multiple commands, processing said commands sequentially; outputting a predetermined control signal to at least one of the first control device and the second control device based on the specific command; delaying the processing of a subsequent command until a predetermined data value is output from the signal modulation unit based on the specific command; The second control device changing the impedance of the path in synchronization with the predetermined control signal; The signal demodulation unit 2. The semiconductor device according to claim 1, wherein the data value is reproduced from a measurement result of the impedance of the path in synchronization with the predetermined control signal.

11. The sequence control unit a control sequence table; The control sequence table 11. The semiconductor device according to claim 10, wherein the contents of the first control device are programmable from outside.

12. The sequence control unit 11. The semiconductor device according to claim 10, wherein control is performed so that the processing time of each of the commands to be processed consecutively is constant.

13. 11. The semiconductor device according to claim 10, wherein the predetermined control signal includes an instruction to turn on or off the operation of the signal demodulation unit.

14. The first control device placed in a first portion having a first temperature cooled by a cooling device; The second control device 2. The semiconductor device according to claim 1, wherein the semiconductor device is disposed in a second portion having a second temperature lower than the first temperature.

15. The second control device 2. The semiconductor device according to claim 1, wherein the semiconductor device executes at least quantum operations.

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