Processing apparatus, processing method, and program

Abstract

To provide a processing device capable of achieving multiplexing of reading when oscillation frequencies of a plurality of Josephson parametric oscillators are the same.SOLUTION: And an identification processing unit configured to identify states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result of a real part and an imaginary part between a Fourier transform value of the signal output by the plurality of Josephson parametric oscillators and a calculated value obtained from a parameter of a pump signal input to the plurality of Josephson parametric oscillators.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a processing device, a processing method, and a program. [Background technology]

[0002] Quantum computers are being developed as one way to speed up computer calculation processing. Patent Document 1 discloses a related technology, which is frequency division multiplexing of quantum bits. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-535169 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technical field related to Patent Document 1, there is a demand for a technique that can realize multiplexing of readout when a plurality of Josephson parametric oscillators have the same oscillation frequency.

[0005] One of the objectives of each aspect of the present disclosure is to provide a processing device, a processing method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a processing device includes a control processing unit that controls the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same, and an identification processing unit that identifies the states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result of a real part and an imaginary part of a Fourier transform value of the signals output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators.

[0007] According to another aspect of the present disclosure, a processing method includes controlling oscillation frequencies of signals output by a plurality of Josephson parametric oscillators to be the same, and identifying states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result of a real part and an imaginary part of a Fourier transform value of the signals output by the plurality of Josephson parametric oscillators with a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators.

[0008] According to another aspect of the present disclosure, a program causes a computer to control the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same, and identify states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result of a real part and an imaginary part of a Fourier transform value of the signals output from the plurality of Josephson parametric oscillators with a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators. [Effects of the Invention]

[0009] According to each aspect of the present disclosure, when the oscillation frequencies of a plurality of Josephson parametric oscillators are the same, multiplexing of readout can be achieved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of a configuration of a processing device according to some embodiments of the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating an example of a processing flow of a processing device according to some embodiments of the present disclosure. [Figure 3] FIG. 10 is a diagram illustrating a first example of control by a processing device according to some embodiments of the present disclosure. [Figure 4] FIG. 10 is a diagram illustrating a second example of control by a processing device according to some embodiments of the present disclosure. [Figure 5]FIG. 10 is a diagram illustrating a third example of control by a processing device according to some embodiments of the present disclosure. [Figure 6] FIG. 1 illustrates an example of a configuration of a processing device according to some embodiments of the present disclosure. [Figure 7] FIG. 1 illustrates an example of a configuration of a processing device according to some embodiments of the present disclosure. [Figure 8] FIG. 1 is a diagram illustrating an example of a processing flow of a processing device according to some embodiments of the present disclosure. [Figure 9] FIG. 1 is a schematic block diagram illustrating the configuration of a computer according to at least one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings. <Embodiment> A processing device 1 according to an embodiment of the present disclosure will be described with reference to the drawings. The processing device 1 is a device that can realize readout multiplexing when multiple Josephson parametric oscillators (hereinafter referred to as "JPOs") have the same oscillation frequency.

[0012] (Configuration of processing device) Fig. 1 is a diagram illustrating an example of the configuration of a processing device 1 according to some embodiments of the present disclosure. As shown in Fig. 1, the processing device 1 includes a signal output unit 10, JPOs 20a1, 20a2, ..., 20aN, couplers 30a1, 30a2, ..., 30aN, a readout unit 40, and a control unit 50. The JPOs 20a1, 20a2, ..., 20aN may be collectively referred to as JPOs 20a. The couplers 30a1, 30a2, ..., 30aN may be collectively referred to as couplers 30a. N is an integer equal to or greater than 2.

[0013] The signal output unit 10 has N output terminals corresponding to the N channels. Under the control of the control unit 50, the signal output unit 10 outputs pump signals to the magnetic field generating units 201 of the JPOs 30 (described later) via the N output terminals. For example, the signal output unit 10 outputs pump signals whose parameters, voltage amplitude V1i and phase θ1i (described later), are manipulated for each channel i (1≦i≦N) by the control unit 50 to set the Fourier transform V(f|{bi}) of the readout signal measured by the readout unit 40 to a desired value. Note that channel i is the ith channel among the N channels. The frequency f of the pump signal is the same for all channels. Examples of the signal output unit 10 include an arbitrary waveform generator, an IQ (In-phase Quadrature) mixer, and a DAC (Digital-to-Analog Converter). However, the signal output unit 10 is not limited to these.

[0014] Each JPO 20a generates an oscillation signal by oscillating in response to an AC magnetic field generated in response to a pump signal. Each JPO 20a outputs the generated oscillation signal to the readout unit 40 via a corresponding coupler 30a. The corresponding coupler 30a is coupler 30a1 for JPO 20a1, coupler 30a2 for JPO 20a2, and coupler 30aN for JPO 20aN.

[0015] 1, each of the JPOs 20a includes a magnetic field generating unit 201, a loop circuit 202, and a capacitor 203. The magnetic field generating unit 201 generates an AC magnetic field in response to a pump signal having a voltage amplitude V2i and a phase θ2i (described later) received from the signal output unit 10. For example, the magnetic field generating unit 201 is magnetically coupled to the loop circuit 202 via mutual inductance. The magnetic field generating unit 201 generates an AC magnetic field and applies the AC magnetic field to the loop circuit 202.

[0016] 1, the loop circuit 202 includes Josephson junctions 2021 and 2022. When each of the JPOs 20a has the configuration shown in FIG. 1, each of the JPOs 20a oscillates at a frequency (f / 2) that is half the frequency f in response to the AC magnetic field generated by the magnetic field generating unit 201.

[0017] Each coupler 30a couples a corresponding JPO 20a to the readout unit 40. Examples of couplers 30a include capacitive coupling, inductive coupling, and resonators. However, the couplers 30a are not limited to these. The corresponding JPO 20a is JPO 20a1 for coupler 30a1, JPO 20a2 for coupler 30a2, and JPO 20aN for coupler 30aN.

[0018] The readout unit 40 receives oscillation signals from the corresponding JPOs 20a via each of the couplers 30a. The readout unit 40 measures the oscillation signals received from each of the JPOs 20a. For example, the readout unit 40 samples the received oscillation signals under the control of the control unit 50 (i.e., according to a sampling frequency specified by the control unit 50). The readout unit 40 then outputs the sampled oscillation signal to the control unit 50. Examples of the readout unit 40 include an ADC (Analog to Digital Converter), a downconverter, and a mixer. However, the readout unit 40 is not limited to these.

[0019] The control unit 50 controls the pump signals that the signal output unit 10 outputs to the magnetic field generation units 201 of the JPOs 20a via the N output terminals. For example, the control unit 50 manipulates the voltage amplitude V1i and phase θ1i (described later), which are parameters of the pump signal, for each channel i (1≦i≦N), in order to set the Fourier transform V(f|{bi}) of the readout signal measured by the readout unit 40 to a desired value.

[0020] Furthermore, the control unit 50 receives from the readout unit 40 the values ​​measured by the readout unit 40. The control unit 50 performs a discrete Fourier transform on the signal indicated by the values ​​received from the readout unit 40. Examples of components of the control unit 50 include, but are not limited to, a personal computer, an FPGA (Field Programmable Gate Array), and a frequency mixing circuit.

[0021] The processing performed by the processing device 1 according to an embodiment of the present disclosure is not limited to the above-described processing. For example, the processing device 1 may perform the processing described below.

[0022] (Processing performed by the processing device) 2 is a diagram illustrating an example of a processing flow of the processing device 1 according to some embodiments of the present disclosure. Next, the processing performed by the processing device 1 will be described with reference to FIG. 2. Here, the processing performed by the processing device 1 will be described, in which the control unit 50 identifies the quantum bit states of multiple JPOs 20 by comparing the Fourier transform value of the measurement signal measured by the readout unit 40 with a calculated value obtained from the parameters of the pump signal input to the JPOs 20.

[0023] The control unit 50 controls the pump signals that the signal output unit 10 outputs to the magnetic field generation units 201 of the JPOs 20a via the N output terminals (step S1). For example, the control unit 50 manipulates the voltage amplitude V1i and phase θ1i, which are parameters of the pump signal, for each channel i (1≦i≦N) in order to set the Fourier transform V(f|{bi}) of the readout signal measured by the readout unit 40 to a desired value.

[0024] Under the control of the control unit 50, the signal output unit 10 outputs pump signals to the magnetic field generation units 201 of each JPO 30 via N output terminals (step S2). For example, the signal output unit 10 outputs a pump signal whose parameters, voltage amplitude V1i and phase θ1i, have been manipulated for each channel i (1≦i≦N) by the control unit 50 in order to set the Fourier transform V(f|{bi}) of the readout signal measured by the readout unit 40 to a desired value. The pump signal P1i(t) output by the signal output unit 10 for channel i can be expressed by a voltage signal shown in equation (1).

[0025]

number

[0026] Here, t represents time, V1i represents voltage amplitude, f1 represents frequency, θ1i represents phase, and gi(t) represents the pulse envelope. Examples of pulse envelopes include a Gaussian function, a rectangular function, and a trapezoidal function. However, the pulse envelope is not limited to these.

[0027] Considering the signal propagation delay along the path from the signal output unit 10 to the magnetic field generating unit 201, the pump signal P2i(t) in the magnetic field generating unit 201 can be expressed by a voltage signal shown in equation (2).

[0028]

number

[0029] Here, V2i indicates the voltage amplitude, and θ2i indicates the phase. The phase θ2i can be expressed as in equation (3).

[0030]

number

[0031] Here, δ1i represents a path delay from the signal output unit 10 to the magnetic field generation unit 201. In general, the voltage amplitude V2i is proportional to the voltage amplitude V1i.

[0032] The magnetic field generating unit 201 generates an AC magnetic field in response to the pump signal having a voltage amplitude V2i and a phase θ2i received from the signal output unit 10 (step S3). Each of the JPOs 20a (i.e., the i-th JPO 20a) outputs an oscillation signal P3i(t) shown in equation (4) in response to the AC magnetic field generated by the magnetic field generating unit 201 (step S4).

[0033]

number

[0034] Here, V3i indicates the voltage amplitude. bi (=±1) is a variable that represents the state of the quantum bit of the i-th JPO20a. For example, the quantum bit states 0 and 1 can be associated with bi = +1 and bi = -1, respectively. f2 indicates the frequency. The frequency f2 can be expressed as in equation (5).

[0035]

number

[0036] θ3i indicates a phase. The phase θ3i can be expressed as in equation (6). The voltage amplitude V3i depends on the voltage amplitude V2i of the pump signal. Therefore, the voltage amplitude V3i is adjustable.

[0037]

number

[0038]

number

[0039]

number

[0040] Here, δ2i represents the path delay from the JPO 20a to the readout unit 40.

[0041] The control unit 50 applies a discrete Fourier transform of frequency f2 to the signal V(t|{bi}) received by the readout unit 40 (step S6). As a result, the control unit 50 obtains the discrete Fourier transform result V(f2|{bi})_measurement value shown in equation (9), which is the result of the discrete Fourier transform of the signal V(t|{bi}) (step S7).

[0042]

number

[0043] Here, j represents an imaginary number. A(f) represents the discrete Fourier transform of A(t) shown in equation (10) at frequency f. gi(f) represents the discrete Fourier transform of gi(t) at frequency f. * represents the circular convolution operator of D points. D represents the number of data points measured by the readout unit 40.

[0044]

number

[0045] If the pulse width of the envelope gi(t) is sufficiently long (i.e., if the reciprocal of the time indicated by the pulse width of the envelope gi(t) is less than a fraction to one-tenth of the frequency f2), the signal V(t|{bi}) can be approximated as a continuous wave, and equation (9) can be simplified to equation (11).

[0046]

number

[0047] The process performed by the control unit 50 in step S1, in which the signal output unit 10 controls the pump signals output to the magnetic field generation units 201 of the JPOs 20a via the N output terminals, is a process of determining the discrete Fourier transform result V(f2|{bi})_set value based on equation (9) or (11). As described above, the voltage amplitude V4i and phase θ4i of the pump signal can be adjusted by manipulating the voltage amplitude V1i and phase θ1i, and the discrete Fourier transform result V(f2|{bi})_set value can be adjusted based on equation (9) or (11).

[0048] The control unit 50 identifies the states of the quantum bits in the multiple (e.g., N) JPOs 20a based on the discrete Fourier transform result V(f2|{bi})_set value and the discrete Fourier transform result V(f2|{bi})_measured value (step S8). For example, the control unit 50 determines {bi} (bi=±1) that minimizes the function F shown in equation (12).

[0049]

number

[0050] In this way, the processing device 1 can identify the states of quantum bits in a plurality of JPOs 20a with the same oscillation frequency.

[0051] FIG. 3 is a diagram illustrating a first example of control by the processing device 1 according to some embodiments of the present disclosure. FIG. 4 is a diagram illustrating a second example of control by the processing device 1 according to some embodiments of the present disclosure. FIG. 5 is a diagram illustrating a third example of control by the processing device 1 according to some embodiments of the present disclosure. FIG. 3 is a diagram illustrating an example of a quantum bit state when there is one JPO 20a. FIG. 4 is a diagram illustrating an example of a quantum bit state when there are two JPOs 20a. FIG. 5 is a diagram illustrating an example of a quantum bit state when there are six JPOs 20a. In FIGS. 3 to 5, the horizontal axis represents the real part of the discrete Fourier transform result V(f2|{bi}) based on Equation (11). In addition, in FIGS. 3 to 5, the vertical axis represents the imaginary part of the discrete Fourier transform result V(f2|{bi}) based on Equation (11). In the examples illustrated in FIGS. 3 to 5, the voltage amplitude V4i of the oscillation signals output by each JPO 20a is the same. In the example illustrated in FIG. 3, the phase θ4i=0 (i=1). In the example shown in FIG. 4, the phase θ4i = (i-1)·π / 2 (i = 1, 2). In the example shown in FIG. 5, the phase θ4i = (i-1)·0.9π / 6 (i = 1, 2, . . . , 6). As can be seen from the examples shown in FIGS. 3 to 5, the quantum bit generated by the processing device 1 is represented by a combination of the real and imaginary parts of the discrete Fourier transform result V(f2|{bi}). Therefore, in the processing device 1, the control unit 50 confirms the combination of the real and imaginary parts by comparing the discrete Fourier transform result V(f2|{bi})_set value with the discrete Fourier transform result V(f2|{bi})_measured value. By comparing the combinations of the real and imaginary parts, the control unit 50 can identify the quantum bit states in multiple JPOs 20a with the same oscillation frequency.

[0052] (advantage) The processing device 1 according to one embodiment of the present disclosure has been described above. In the processing device 1, the control unit 50 (an example of a control processing unit) controls the oscillation frequencies of the oscillation signals P3i(t) (an example of a signal) output from N Josephson parametric oscillators 20a (an example of a plurality of Josephson parametric oscillators) to be the same. The control unit 50 (an example of an identification processing unit) identifies the states of the quantum bits of the N Josephson parametric oscillators 20a based on the results of comparing the Fourier transform values ​​of the oscillation signals P3i(t) output from the N Josephson parametric oscillators 20a with the real and imaginary parts of calculated values ​​obtained from parameters of the pump signals input to the N Josephson parametric oscillators 20a. This processing device 1 can realize readout multiplexing when the oscillation frequencies of the multiple Josephson parametric oscillators are the same.

[0053] <Modifications of the embodiment> A processing device 1 according to a modified example of an embodiment of the present disclosure will be described with reference to the drawings.

[0054] (Configuration of processing device) 6 is a diagram illustrating an example of the configuration of a processing device 1 according to some embodiments of the present disclosure. As shown in FIG. 6, the processing device 1 according to a modified embodiment of the present disclosure includes, similarly to the processing device 1 according to an embodiment of the present disclosure, a signal output unit 10, JPOs 20a1, 20a2, . . . , 20aN, couplers 30a1, 30a2, . . . , 30aN, a readout unit 40, and a control unit 50. Furthermore, as shown in FIG. 6, the processing device 1 according to a modified embodiment of the present disclosure further includes phase shifters 60a1, 60a2, . . . , 60aN. The phase shifters 60a1, 60a2, . . . , 60aN may be collectively referred to as phase shifter 60a.

[0055] The phase shifter 60a1 is provided between the coupler 30a1 and the readout unit 40. The phase shifter 60a2 is provided between the coupler 30a2 and the readout unit 40. The phase shifter 60aN is provided between the coupler 30aN and the readout unit 40. Each of the phase shifters 60a is capable of manipulating the phase of a high-frequency signal. Examples of the phase shifter 60a include a phase shifter, a delay circuit, and a filter. However, the phase shifter 60a is not limited to these. If the amount of phase shift obtained by the phase shifter 60a is δphase i, the phase of the signal received by the readout unit 40 is expressed as in equation (13).

[0056]

number

[0057] By adjusting the phase shift amount δ phase i of each phase shifter 60a, it is possible to independently adjust the phase θ4i of the signal received by the readout unit 40 and the phase θ3i of the oscillation signal P3i(t) output by the JPO 20a.

[0058] (advantage) The above has described the processing device 1 according to a modified example of an embodiment of the present disclosure. The phase shifter 60a included in the processing device 1 makes it possible to independently adjust the phase θ4i of the signal received by the readout unit 40 and the phase θ3i of the oscillation signal P3i(t) output by the JPO 20a.

[0059] A processing device 1 according to some embodiments of the present disclosure will be described. Fig. 7 is a diagram showing an example of the configuration of the processing device 1 according to some embodiments of the present disclosure. As shown in Fig. 7, the processing device 1 includes a control processing unit 701 and an identification processing unit 702.

[0060] A control processing unit 701 controls the oscillation frequencies of the signals output from the plurality of Josephson parametric oscillators to be the same. An identification processing unit 702 identifies the states of the quantum bits of the plurality of Josephson parametric oscillators based on the results of comparing the Fourier transform values ​​of the signals output from the plurality of Josephson parametric oscillators with the real and imaginary parts of calculated values ​​obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators.

[0061] The control processing unit 701 can be realized, for example, by using the functions of the control unit 50 illustrated in Figures 1 and 6. The identification processing unit 702 can be realized, for example, by using the functions of the control unit 50 illustrated in Figures 1 and 6.

[0062] Next, processing performed by the processing device 1 according to some embodiments of the present disclosure will be described. Fig. 8 is a diagram showing an example of a processing flow of the processing device 1 according to some embodiments of the present disclosure. Here, the processing of the processing device 1 will be described with reference to Fig. 8.

[0063] The control processing unit 701 controls the oscillation frequencies of the signals output from the plurality of Josephson parametric oscillators to be the same (step S101). The identification processing unit 702 identifies the states of the quantum bits of the plurality of Josephson parametric oscillators based on the results of comparing the Fourier transform values ​​of the signals output from the plurality of Josephson parametric oscillators with the real and imaginary parts of calculated values ​​obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators (step S102).

[0064] The processing device 1 according to some embodiments of the present disclosure has been described above. The processing device 1 can realize readout multiplexing when the oscillation frequencies of multiple Josephson parametric oscillators are the same.

[0065] The order of the processes in each embodiment of the present disclosure may be changed as long as the processes are performed appropriately.

[0066] Each embodiment of the present disclosure has been described. The processing device 1, signal output unit 10, JPO 20a, coupler 30a, readout unit 40, control unit 50, and other control devices may have a computer system built therein. The above-described processing steps are stored in the form of a program on a computer-readable recording medium, and the computer reads and executes this program to perform the above processing. Specific examples of computers are shown below.

[0067] 9 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. As shown in FIG. 9, the computer 5 includes a CPU (Central Processing Unit) 6, a main memory 7, a storage 8, and an interface 9.

[0068] For example, the above-mentioned processing device 1, signal output unit 10, JPO 20a, coupler 30a, readout unit 40, control unit 50, and other control devices are each implemented in a computer 5. The operations of the above-mentioned processing units are stored in the storage 8 in the form of a program. The CPU 6 reads the program from the storage 8, loads it into the main memory 7, and executes the above-mentioned processing in accordance with the program. The CPU 6 also allocates storage areas in the main memory 7 corresponding to the above-mentioned storage units in accordance with the program.

[0069] Examples of storage 8 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. Storage 8 may be an internal medium directly connected to the bus of computer 5, or an external medium connected to computer 5 via interface 9 or a communication line. In addition, when this program is distributed to computer 5 via a communication line, computer 5 that receives the program may load the program into main memory 7 and execute the above-mentioned processing. In at least one embodiment, storage 8 is a non-transitory tangible storage medium.

[0070] The program may also implement some of the functions described above. Furthermore, the program may be a file that can implement the functions described above in combination with a program already recorded in the computer system, a so-called differential file (differential program).

[0071] Although several embodiments of the present disclosure have been described, these embodiments are merely examples and do not limit the scope of the disclosure. Various additions, omissions, substitutions, and modifications may be made to these embodiments without departing from the spirit of the disclosure.

[0072] Note that part or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0073] (Appendix 1) a control processing unit that controls the oscillation frequencies of signals output from the plurality of Josephson parametric oscillators to be the same; an identification processing unit that identifies states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A processing device comprising:

[0074] (Appendix 2) The control processing unit The amplitude and phase parameters are adjustable. 10. The processing device of claim 1.

[0075] (Appendix 3) The identification processing unit identifying a state of the quantum bit based on a combination of the real part and the imaginary part of the Fourier transform value and a combination of the real part and the imaginary part of the calculated value; 10. The processing device of claim 1 or 2.

[0076] (Appendix 4) The combination of the real part and the imaginary part in the Fourier transform value is Identified by the amplitude and phase of the signals output by the plurality of Josephson parametric oscillators. 4. The processing device of claim 3.

[0077] (Appendix 5) The combination of the real part and the imaginary part in the calculated value is Identified based on the parameters amplitude and phase, 5. The processing device of claim 3 or 4.

[0078] (Appendix 6) a phase processing unit capable of adjusting the phases of the signals output from the plurality of Josephson parametric oscillators; 6. The processing device according to any one of claims 1 to 5, comprising:

[0079] (Appendix 7) Controlling the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same; Identifying the states of the quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A processing method comprising:

[0080] (Appendix 8) The parameters amplitude and phase are adjustable. The processing method described in Appendix 7.

[0081] (Appendix 9) identifying a state of the quantum bit based on a combination of the real and imaginary parts of the Fourier transform value and a combination of the real and imaginary parts of the calculated value; 10. The method of claim 7 or 8, comprising:

[0082] (Appendix 10) The combination of the real part and the imaginary part in the Fourier transform value is Identified by the amplitude and phase of the signals output by the plurality of Josephson parametric oscillators. The processing method described in Appendix 9.

[0083] (Appendix 11) The combination of the real part and the imaginary part in the calculated value is Identified based on the parameters amplitude and phase, 10. The method of claim 9 or 10.

[0084] (Appendix 12) the phases of the signals output by the plurality of Josephson parametric oscillators are adjustable; 12. The processing method according to any one of claims 7 to 11.

[0085] (Appendix 13) On the computer, Controlling the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same; Identifying the states of the quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A program that executes the following.

[0086] (Appendix 14) The parameters amplitude and phase are adjustable. 13. The program described in Appendix 13.

[0087] (Appendix 15) identifying a state of the quantum bit based on a combination of the real and imaginary parts of the Fourier transform value and a combination of the real and imaginary parts of the calculated value; 15. The program according to claim 13 or 14, which causes the computer to execute the above.

[0088] (Appendix 16) The combination of the real part and the imaginary part in the Fourier transform value is Identified by the amplitude and phase of the signals output by the plurality of Josephson parametric oscillators. 15. The program described in Appendix 15.

[0089] (Appendix 17) The combination of the real part and the imaginary part in the calculated value is Identified based on the parameters amplitude and phase, 17. The program according to claim 15 or 16.

[0090] (Appendix 18) the phases of the signals output by the plurality of Josephson parametric oscillators are adjustable; 18. A program according to any one of appendices 13 to 17. [Explanation of symbols]

[0091] 1 Processing equipment 5. Computer 6 CPU 7. Main memory 8. Storage 9. Interface 10. Signal output section 20a, 20a1, 20a2, 20aN...JPO 30a, 30a1, 30a2, 30aN...Coupler 40 Readout section 50 Control unit 201 Magnetic field generating unit 202 Loop circuit 203 Capacitor 2021, 2022···Josephson junction

Claims

1. a control processing unit that controls the oscillation frequencies of signals output from the plurality of Josephson parametric oscillators to be the same; an identification processing unit that identifies states of quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A processing device comprising:

2. The control processing unit The amplitude and phase parameters are adjustable. The processing device of claim 1 .

3. The identification processing unit identifying a state of the quantum bit based on a combination of the real part and the imaginary part of the Fourier transform value and a combination of the real part and the imaginary part of the calculated value; The processing device of claim 1 .

4. The combination of the real part and the imaginary part in the Fourier transform value is Identified by the amplitude and phase of the signals output by the plurality of Josephson parametric oscillators. The processing device according to claim 3 .

5. The combination of the real part and the imaginary part in the calculated value is Identified based on the parameters amplitude and phase, The processing device according to claim 3 .

6. a phase processing unit capable of adjusting the phases of the signals output from the plurality of Josephson parametric oscillators; The processing device of claim 1 , comprising:

7. Controlling the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same; Identifying the states of the quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A processing method comprising:

8. On the computer, Controlling the oscillation frequencies of signals output from a plurality of Josephson parametric oscillators to be the same; Identifying the states of the quantum bits of the plurality of Josephson parametric oscillators based on a comparison result between a real part and an imaginary part of a Fourier transform value of the signal output from the plurality of Josephson parametric oscillators and a calculated value obtained from parameters of pump signals input to the plurality of Josephson parametric oscillators; A program that executes the following.

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