WO2021029063A1 - Quantum circuit system - Google Patents
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- WO2021029063A1 WO2021029063A1 PCT/JP2019/032042 JP2019032042W WO2021029063A1 WO 2021029063 A1 WO2021029063 A1 WO 2021029063A1 JP 2019032042 W JP2019032042 W JP 2019032042W WO 2021029063 A1 WO2021029063 A1 WO 2021029063A1
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N10/00—Quantum computing, i.e. information processing based on quantum-mechanical phenomena
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N60/00—Superconducting devices
- H10N60/10—Junction-based devices
Definitions
- the present invention relates to a quantum circuit system.
- Transmon is highly resistant to electrical noise and has a relatively long relaxation time.
- Patent Document 1 describes a quantum information processing system including a waveguide having an aperture, a nonlinear quantum circuit arranged in the waveguide, and an electromagnetic field source coupled to the aperture.
- Patent Document 2 describes an uninterrupted elongated thin film due to Josephson junction and a superconducting quantum interference device (SQUID) in electrical contact with the proximal end of the elongated thin film, with less than three Josephsons.
- a superconducting quantum interference device (SQUID) with junctions and a ground plane that is coplanar with the elongated thin film and is in electrical contact with the distal end of the elongated thin film, the thin film, SQUID and ground plane are designed.
- Quantum bit devices are described that include materials that are superconducting at the given operating temperature.
- the quantum state of a quantum circuit such as Transmon may be manipulated by propagating high-frequency power to a waveguide connected to the quantum circuit. At this time, the electromagnetic field propagating in the waveguide may leak and power may propagate to other waveguides, and the quantum state of the quantum circuit connected to the other waveguide may change unintentionally. is there.
- the present invention provides a quantum circuit system that can prevent unintended changes in the quantum state.
- the quantum circuit system includes a first quantum circuit and a second quantum circuit having at least two quantum states, respectively, and a first waveguide and a second quantum electromagnetically connected to the first quantum circuit.
- the quantum state of the second quantum circuit when the first quantum circuit is changed to a predetermined quantum state by propagating the first high-frequency power to the second waveguide electromagnetically connected to the circuit and the first waveguide.
- a high frequency power source that propagates the second high frequency power to the second waveguide directly or indirectly is provided so as to compensate for the change.
- the change in the quantum state of the second quantum circuit can be compensated, and the unintended change in the quantum state of the second quantum circuit can be prevented. can do.
- the high frequency power supply directly or indirectly performs the second induction so as to compensate for the change in the quantum state of the second quantum circuit after the timing when the first high frequency power is propagated to the first waveguide.
- the second high frequency power may be propagated through the waveguide.
- the high-frequency power supply changes the high-frequency power that compensates for the change in the quantum state of the second quantum circuit due to the propagation of the first high-frequency power through the first waveguide and the second quantum circuit into a predetermined quantum state.
- the second high-frequency power which is a superposition with the high-frequency power to be caused, may be directly or indirectly propagated to the second waveguide.
- the quantum state of the second quantum circuit is changed to a predetermined quantum state while compensating for the change of the quantum state of the second quantum circuit caused by changing the first quantum circuit to a predetermined quantum state. Can be made to.
- the high frequency power source propagates the first high frequency power to the first waveguide to change the first quantum circuit into a predetermined quantum state.
- the third high-frequency power may be propagated to the auxiliary waveguide and indirectly propagate the second high-frequency power to the second waveguide so as to compensate for the change in the quantum state of the second quantum circuit.
- the first quantum circuit when the first quantum circuit is changed to a predetermined quantum state, it is possible to compensate for the change in the quantum state of the second quantum circuit without propagating high-frequency power directly to the second waveguide. it can.
- the auxiliary waveguide may include a first portion and a second portion extending along the second waveguide, and a folded portion connecting the first portion and the second portion.
- the second high frequency power when the third high frequency power is propagated to the auxiliary waveguide, the second high frequency power can be propagated to the second waveguide more accurately.
- FIG. 1 is a diagram showing a network configuration of the quantum computing system 100 according to the embodiment of the present invention.
- the quantum computing system 100 includes a quantum circuit system 10 and a user terminal 20.
- the quantum circuit system 10 and the user terminal 20 are communicably connected to each other via a communication network N such as the Internet.
- the user of the quantum calculation system 100 inputs data to the quantum circuit system 10 using the user terminal 20 composed of a general-purpose classical computer, and acquires the result of the quantum calculation performed by the quantum circuit system 10. ..
- FIG. 2 is a diagram showing the configuration of the quantum circuit system 10 according to the present embodiment.
- the quantum circuit system 10 includes a first quantum circuit 11a and a second quantum circuit 11b having at least two quantum states, respectively, and a first waveguide 12a and a second quantum circuit 11b electromagnetically connected to the first quantum circuit 11a.
- a second waveguide 12b, which is electromagnetically connected to the circuit, is provided.
- the quantum circuit system 10 compensates for the change in the quantum state of the second quantum circuit 11b when the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a to a predetermined quantum state.
- a second high-frequency power supply 13b for propagating the second high-frequency power directly or indirectly to the second waveguide 12b is provided.
- the quantum circuit system 10 compensates for the change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first high-frequency power source 13a for propagating high-frequency power directly or indirectly to the first waveguide 12a is provided.
- the quantum circuit system 10 includes a third quantum circuit 11c and a fourth quantum circuit 11d having at least two quantum states, respectively, and a third waveguide 12c and a fourth quantum electromagnetically connected to the third quantum circuit 11c.
- a fourth waveguide 12d, which is electromagnetically connected to the circuit 11d, is further provided.
- the quantum circuit system 10 compensates for the change in the quantum state of the fourth quantum circuit 11d when the third high frequency power is propagated to the third waveguide 12c to change the third quantum circuit 11c to a predetermined quantum state.
- a fourth high-frequency power source 13d for propagating the fourth high-frequency power directly or indirectly to the fourth waveguide 12d is provided.
- the quantum circuit system 10 compensates for the change in the quantum state of the third quantum circuit 11c when the high frequency power is propagated to the fourth waveguide 12d to change the fourth quantum circuit 11d to a predetermined quantum state.
- a third high-frequency power source 13c that propagates high-frequency power directly or indirectly to the third waveguide 12c is provided.
- the first quantum circuit 11a, the second quantum circuit 11b, the third quantum circuit 11c, and the fourth quantum circuit 11d may each have the same configuration, and may be, for example, a quantum circuit containing Transmon.
- the first waveguide 12a, the second waveguide 12b, the third waveguide 12c, and the fourth waveguide 12d may each have the same configuration, and are, for example, a waveguide including a coplanar line, a microstrip line, and the like. Good.
- the first high-frequency power supply 13a, the second high-frequency power supply 13b, the third high-frequency power supply 13c, and the fourth high-frequency power supply 13d may each have the same configuration, and may include, for example, a power supply that outputs a high-frequency pulse of several GHz.
- a plurality of quantum circuits including the first quantum circuit 11a, the second quantum circuit 11b, the third quantum circuit 11c, and the fourth quantum circuit 11d are simply referred to as quantum circuits 11.
- a plurality of waveguides including the first waveguide 12a, the second waveguide 12b, the third waveguide 12c, and the fourth waveguide 12d are simply referred to as the waveguide 12, and the first high frequency power supply 13a and the second high frequency power supply 13b.
- a plurality of high-frequency power supplies including the third high-frequency power supply 13c and the fourth high-frequency power supply 13d are simply referred to as high-frequency power supplies 13.
- FIG. 2 illustrates a quantum circuit system 10 including four quantum circuits 11, four waveguides 12, and four high-frequency power supplies 13, but the number of quantum circuits 11, waveguides 12, and high-frequency power supplies 13 is illustrated. Is optional.
- the number of high-frequency power supplies 13 may be smaller than the number of quantum circuits 11, and the structure may be connected to the quantum circuits 11 via a demultiplexer or the like.
- FIG. 3 is an example of a circuit diagram of the quantum circuit 11 according to the present embodiment.
- Quantum circuit 11 includes a Toranzumon 111 including Josephson junction JJ and capacitor C B, a resonator 112 includes an inductor L r and a capacitor C r.
- the high-frequency power supply 13 is connected to one end of the input capacitor C in , and the high-frequency pulse output from the high-frequency power supply 13 is input to the transmon 111 via the gate capacitor C g to change the quantum state of the transmon 111.
- the number of Josephson junction JJs is not limited to one, but when two are connected in parallel to form a dc-SQUID configuration, or when Josephson junction JJs of different sizes are connected in parallel (Flux qubit, etc.), There may be cases where multiple Josephson-joined JJs of different sizes are connected (Fluxonium, etc.). In this way, the energy potential of the system may be adjusted according to the purpose depending on the number and size of the Josephson junction JJ.
- FIG. 4 is a diagram showing a first example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10 according to the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a a waveform graph showing the relationship between the voltage and time of the second waveguide 12b, and a bloch sphere showing the quantum state of the second quantum circuit 11b. It shows that.
- the voltage graph of the first waveguide 12a and the second waveguide 12b is shown, but the high frequency pulse propagates to the first waveguide 12a and the second waveguide 12b. Therefore, electric power that is not clearly separated into voltage and current is propagated.
- the change in the quantum state of the second quantum circuit 11b is compensated for.
- An example of propagating the second high-frequency power to the two waveguides 12b will be described, but the relationship may be reversed. That is, when high-frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state, the first waveguide is compensated for the change in the quantum state of the first quantum circuit 11a.
- High frequency power may be propagated to 12a.
- the same processing may be performed between the second waveguide 12b and the third waveguide 12c, or the same processing may be performed between the third waveguide 12c and the fourth waveguide 12d. ..
- the second high-frequency power source 13b directly or indirectly propagates the second high-frequency power to the second waveguide 12b so as to compensate for the change in the quantum state of the second quantum circuit 11b.
- the second high-frequency power supply 13b directly or indirectly compensates for the change in the quantum state of the second quantum circuit 11b after the timing when the first high-frequency power is propagated to the first waveguide 12a. Therefore, the second high frequency power is propagated through the second waveguide 12b. More specifically, in the case of this example, the second high-frequency power supply 13b compensates for the change in the quantum state of the second quantum circuit 11b after the timing at which the first high-frequency power is propagated to the first waveguide 12a. As described above, the second high frequency power is directly propagated to the second waveguide 12b.
- the quantum state of the second quantum circuit 11b after compensation is shown by a Bloch sphere in which the direction of the qubit is returned vertically upward.
- the magnitude of the second high-frequency power propagated to the second waveguide 12b so as to compensate for the change in the quantum state of the second quantum circuit 11b depends on the physical characteristics of the plurality of materials constituting the quantum circuit system 10 and the first. It may be calculated theoretically based on the arrangement of the 1 waveguide 12a and the 2nd waveguide 12b, or may be experimentally determined by actually operating the quantum circuit system 10.
- the change in the quantum state of the second quantum circuit 11b can be compensated, and the unintended change in the quantum state of the second quantum circuit 11b can be caused. Can be prevented.
- the high frequency power supply 13 other than the second high frequency power supply 13b it is possible to prevent an unintended change in the quantum state of the arbitrary quantum circuit 11.
- FIG. 5 is a diagram showing a second example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10 according to the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a a waveform graph showing the relationship between the voltage and time of the second waveguide 12b, and a bloch sphere showing the quantum state of the second quantum circuit 11b. It shows that.
- the voltage graph of the first waveguide 12a and the second waveguide 12b is shown, but the high frequency pulse propagates to the first waveguide 12a and the second waveguide 12b. Therefore, electric power that is not clearly separated into voltage and current is propagated.
- the change in the quantum state of the second quantum circuit 11b is compensated for.
- An example of propagating the second high-frequency power to the two waveguides 12b will be described, but the relationship may be reversed. That is, when high-frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state, the first waveguide is compensated for the change in the quantum state of the first quantum circuit 11a.
- High frequency power may be propagated to 12a.
- the same processing may be performed between the second waveguide 12b and the third waveguide 12c, or the same processing may be performed between the third waveguide 12c and the fourth waveguide 12d. ..
- the first high-frequency power When the first high-frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a into a predetermined quantum state, a relatively large first high-frequency power is input to the first waveguide 12a, and the first waveguide A leaking electromagnetic field is generated around 12a. Then, due to the influence of the leaking electromagnetic field, unintended high-frequency power propagates to the second waveguide 12b adjacent to the first waveguide 12a, and the quantum state of the second quantum circuit 11b changes.
- the second high-frequency power source 13b directly or indirectly propagates the second high-frequency power to the second waveguide 12b so as to compensate for the change in the quantum state of the second quantum circuit 11b.
- the second high-frequency power supply 13b directly compensates for the change in the quantum state of the second quantum circuit 11b at the same time as the timing at which the first high-frequency power is propagated to the first waveguide 12a.
- the second high frequency power is propagated in the second waveguide 12b.
- FIG. 5 shows that the quantum state of the second quantum circuit 11b does not change before and after the first high-frequency power is input by the Bloch sphere in which the direction of the qubit remains vertically upward and does not change. ..
- the change in the quantum state of the second quantum circuit 11b can be compensated, and the unintended change in the quantum state of the second quantum circuit 11b can be caused. Can be prevented.
- the high frequency power supply 13 other than the second high frequency power supply 13b it is possible to prevent an unintended change in the quantum state of the arbitrary quantum circuit 11.
- FIG. 6 is a diagram showing a third example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10 according to the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a a waveform graph showing the relationship between the voltage and time of the second waveguide 12b, and a bloch sphere showing the quantum state of the second quantum circuit 11b. It shows that.
- the voltage graph of the first waveguide 12a and the second waveguide 12b is shown, but the high frequency pulse propagates to the first waveguide 12a and the second waveguide 12b. Therefore, electric power that is not clearly separated into voltage and current is propagated.
- the change in the quantum state of the second quantum circuit 11b is compensated for.
- An example of propagating the second high-frequency power to the two waveguides 12b will be described, but the relationship may be reversed. That is, when high-frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state, the first waveguide is compensated for the change in the quantum state of the first quantum circuit 11a.
- High frequency power may be propagated to 12a.
- the same processing may be performed between the second waveguide 12b and the third waveguide 12c, or the same processing may be performed between the third waveguide 12c and the fourth waveguide 12d. ..
- the second high-frequency power supply 13b has a high-frequency power that compensates for a change in the quantum state of the second quantum circuit 11b due to propagation of the first high-frequency power through the first waveguide 12a, and a predetermined quantum state of the second quantum circuit 11b.
- the second high-frequency power which is a superposition with the high-frequency power that is changed to, is directly or indirectly propagated to the second waveguide 12b.
- the second high frequency power supply 13b propagates the first high frequency power to the first waveguide 12a after the timing when the first high frequency power is propagated to the first waveguide 12a, so that the second quantum
- the second high-frequency power which is the superposition of the high-frequency power that compensates for the change in the quantum state of the circuit 11b and the high-frequency power that changes the second quantum circuit 11b to a predetermined quantum state, is directly applied to the second waveguide 12b. It is propagated to.
- FIG. 6 the second high-frequency power whose pulse height is lowered by ⁇ due to compensation is illustrated, and the quantum state of the second quantum circuit 11b is changed to a predetermined quantum state horizontally to the right by the second high-frequency power including compensation.
- the magnitude ⁇ of the compensation may be theoretically calculated based on the physical characteristics of the plurality of materials constituting the quantum circuit system 10 and the arrangement of the first waveguide 12a and the second waveguide 12b.
- the quantum circuit system 10 may be put into operation and determined experimentally.
- the quantum state of the second quantum circuit 11b is changed to a predetermined quantum state. Can be changed.
- FIG. 7 is a diagram showing a fourth example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10 according to the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a a waveform graph showing the relationship between the voltage and time of the second waveguide 12b, and a bloch sphere showing the quantum state of the second quantum circuit 11b. It shows that.
- the voltage graph of the first waveguide 12a and the second waveguide 12b is shown, but the high frequency pulse propagates to the first waveguide 12a and the second waveguide 12b. Therefore, electric power that is not clearly separated into voltage and current is propagated.
- the first high-frequency power source 13a indirectly propagates the second high-frequency power to the second waveguide 12b so as to compensate for the change in the quantum state of the second quantum circuit 11b.
- the first high-frequency power supply 13a indirectly compensates for the change in the quantum state of the second quantum circuit 11b after the timing at which the first high-frequency power is propagated to the first waveguide 12a.
- the second high frequency power is propagated to the second waveguide 12b. More specifically, the first high-frequency power supply 13a compensates for the change in the quantum state of the second quantum circuit 11b after the timing at which the first high-frequency power is propagated to the first waveguide 12a.
- the high frequency power having a phase opposite to that of the high frequency power is propagated to the first waveguide 12a, and the second high frequency power is indirectly propagated to the second waveguide 12b by the leakage electromagnetic field.
- the quantum state of the second quantum circuit 11b after compensation is shown by a Bloch sphere in which the direction of the qubit is returned vertically upward.
- the magnitude of the high-frequency power having a phase opposite to that of the first high-frequency power propagated in the first waveguide 12a so as to compensate for the change in the quantum state of the second quantum circuit 11b is determined by the plurality of materials constituting the quantum circuit system 10. It may be calculated theoretically based on the physical characteristics and the arrangement of the first waveguide 12a and the second waveguide 12b, or it may be experimentally determined by actually operating the quantum circuit system 10.
- the change in the quantum state of the second quantum circuit 11b can be compensated, and the unintended change in the quantum state of the second quantum circuit 11b can be caused. Can be prevented.
- FIG. 8 is a diagram showing a configuration of a quantum circuit system 10a according to a first modification of the present embodiment.
- the quantum circuit system 10a according to the first modification is the first quantum circuit 11a and the second quantum circuit 11b having at least two quantum states, respectively, and the first waveguide 12a electromagnetically connected to the first quantum circuit 11a. And a second waveguide 12b electromagnetically connected to the second quantum circuit 11b.
- the quantum circuit system 10a according to the first modification includes a second auxiliary waveguide 15b extending along the second waveguide 12b.
- the quantum circuit system 10a according to the first modification is a case where the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a to a predetermined quantum state
- the second quantum circuit 11b A second auxiliary high frequency power supply 16b that propagates the third high frequency power to the second auxiliary waveguide 15b and indirectly propagates the second high frequency power to the second auxiliary waveguide 12b so as to compensate for the change in the quantum state. Be prepared.
- the quantum circuit system 10a according to the first modification is a change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first auxiliary high-frequency power source 16a that propagates high-frequency power to the first auxiliary waveguide 15a and indirectly propagates high-frequency power to the first auxiliary waveguide 12a is provided so as to compensate for the above.
- auxiliary waveguides including the first auxiliary waveguide 15a and the second auxiliary waveguide 15b are simply referred to as auxiliary waveguides 15.
- auxiliary high frequency power supplies including the first auxiliary high frequency power supply 16a and the second auxiliary high frequency power supply 16b are simply referred to as auxiliary high frequency power supplies 16.
- FIG. 8 relates to a first variation example including two quantum circuits 11, two waveguides 12, two high frequency power supplies 13, two auxiliary waveguides 15, and two auxiliary high frequency power supplies 16.
- the quantum circuit system 10a is illustrated, the number of the quantum circuit 11, the waveguide 12, the high frequency power supply 13, the auxiliary waveguide 15, and the auxiliary high frequency power supply 16 is arbitrary.
- FIG. 9 is a diagram showing a first example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10a according to the first modification of the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a
- a waveform graph showing the relationship between the voltage and time of the second waveguide 12b
- an auxiliary waveguide second auxiliary waveguide 15b
- a waveform graph showing the relationship between voltage and time and a Bloch sphere showing the quantum state of the second quantum circuit 11b are shown.
- the voltage graphs of the first waveguide 12a, the second waveguide 12b, and the second auxiliary waveguide 15b are shown, but the first waveguide 12a and the second waveguide 12b are shown. And it is the high frequency pulse that propagates in the second auxiliary waveguide 15b, and the electric power that is not clearly separated into the voltage and the current propagates.
- the change in the quantum state of the second quantum circuit 11b is compensated for.
- An example of propagating the third high-frequency power to the auxiliary waveguide 15b will be described, but this relationship may be reversed. That is, when high-frequency power is propagated through the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state, the first auxiliary induction is compensated for the change in the quantum state of the first quantum circuit 11a. High frequency power may be propagated through the waveguide 15a.
- the second auxiliary high frequency power supply 16b propagates the third high frequency power to the second auxiliary waveguide 15b so as to compensate for the change in the quantum state of the second quantum circuit 11b, and indirectly to the second waveguide 12b. 2 Propagate high frequency power. More specifically, in the case of this example, the second auxiliary high-frequency power source 16b compensates for the change in the quantum state of the second quantum circuit 11b after the timing at which the first high-frequency power is propagated to the first waveguide 12a. As such, the third high-frequency power is propagated to the second auxiliary waveguide 15b, and the second high-frequency power is indirectly propagated to the second waveguide 12b.
- the quantum state of the second quantum circuit 11b after compensation is shown by a Bloch sphere in which the direction of the qubit is returned vertically upward.
- the magnitude of the third high-frequency power propagated to the second auxiliary waveguide 15b so as to compensate for the change in the quantum state of the second quantum circuit 11b depends on the physical characteristics of the plurality of materials constituting the quantum circuit system 10 and the physical characteristics of the plurality of materials. It may be calculated theoretically based on the arrangement of the first waveguide 12a, the second waveguide 12b, and the second auxiliary waveguide 15b, or the quantum circuit system 10a according to the first modification may be put into operation experimentally. It may be set to.
- the change in the quantum state of the second quantum circuit 11b is compensated without directly propagating the high frequency power to the second waveguide 12b. Can be done.
- FIG. 10 is a diagram showing a second example of the waveform of the first waveguide 12a, the waveform of the second waveguide 12b, and the quantum state of the second quantum circuit 11b of the quantum circuit system 10a according to the first modification of the present embodiment.
- a waveform graph showing the relationship between the voltage and time of the first waveguide 12a
- a waveform graph showing the relationship between the voltage and time of the second waveguide 12b
- an auxiliary waveguide second auxiliary waveguide 15b
- a waveform graph showing the relationship between voltage and time and a Bloch sphere showing the quantum state of the second quantum circuit 11b are shown.
- the voltage graphs of the first waveguide 12a, the second waveguide 12b, and the second auxiliary waveguide 15b are shown, but the first waveguide 12a and the second waveguide 12b are shown. And it is the high frequency pulse that propagates in the second auxiliary waveguide 15b, and the electric power that is not clearly separated into the voltage and the current propagates.
- the change in the quantum state of the second quantum circuit 11b is compensated for.
- An example of propagating the third high-frequency power to the auxiliary waveguide 15b will be described, but this relationship may be reversed. That is, when high-frequency power is propagated through the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state, the first auxiliary induction is compensated for the change in the quantum state of the first quantum circuit 11a. High frequency power may be propagated through the waveguide 15a.
- the second auxiliary high frequency power supply 16b propagates the third high frequency power to the second auxiliary waveguide 15b so as to compensate for the change in the quantum state of the second quantum circuit 11b, and indirectly to the second waveguide 12b. 2 Propagate high frequency power. More specifically, in the case of this example, the second auxiliary high-frequency power source 16b compensates for the change in the quantum state of the second quantum circuit 11b at the same time as the timing at which the first high-frequency power is propagated to the first waveguide 12a. As described above, the third high frequency power is propagated to the second auxiliary waveguide 15b, and the second high frequency power is indirectly propagated to the second waveguide 12b. In FIG. 10, the fact that the quantum state of the second quantum circuit 11b does not change before and after the first high-frequency power is input is shown by the Bloch sphere in which the direction of the qubit remains vertically upward and does not change. ..
- the magnitude of the third high-frequency power propagated to the second auxiliary waveguide 15b so as to compensate for the change in the quantum state of the second quantum circuit 11b depends on the physical characteristics of the plurality of materials constituting the quantum circuit system 10 and the physical characteristics of the plurality of materials. It may be calculated theoretically based on the arrangement of the first waveguide 12a, the second waveguide 12b, and the second auxiliary waveguide 15b, or the quantum circuit system 10a according to the first modification may be put into operation experimentally. It may be set to.
- the change in the quantum state of the second quantum circuit 11b is compensated without directly propagating the high frequency power to the second waveguide 12b. Can be done.
- FIG. 11 is a diagram showing a configuration of a quantum circuit system 10b according to a second modification of the present embodiment.
- the quantum circuit system 10b according to the second modification has a first quantum circuit 11a and a second quantum circuit 11b having at least two quantum states, respectively, and a first waveguide 12a electromagnetically connected to the first quantum circuit 11a. And a second waveguide 12b electromagnetically connected to the second quantum circuit 11b.
- the quantum circuit system 10b according to the second modification includes a second auxiliary waveguide 15b extending along the second waveguide 12b.
- the quantum circuit system 10b according to the second modification is a case where the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a to a predetermined quantum state, and the second quantum circuit 11b A second auxiliary high frequency power supply 16b that propagates the third high frequency power to the second auxiliary waveguide 15b and indirectly propagates the second high frequency power to the second auxiliary waveguide 12b so as to compensate for the change in the quantum state. Be prepared.
- the quantum circuit system 10b according to the second modification is a change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first auxiliary high-frequency power source 16a that propagates high-frequency power to the first auxiliary waveguide 15a and indirectly propagates high-frequency power to the first auxiliary waveguide 12a is provided so as to compensate for the above.
- the second auxiliary waveguide 15b has a first portion 151b and a second portion 152b extending along the second waveguide 12b, and a first portion 151b and a second portion 152b. Includes a folded-back portion 153b to connect the.
- the first auxiliary waveguide 15a includes a first portion 151a and a second portion 152a extending along the first waveguide 12a, and a folded-back portion 153a connecting the first portion 151a and the second portion 152a.
- the auxiliary waveguide 15 by configuring the auxiliary waveguide 15 with the first portion 151, the second portion 152, and the folded portion 153, the first portion 151 in which a relatively uniform electromagnetic field is generated can be adjacent to the waveguide 12. Therefore, when the third high frequency power is propagated to the auxiliary waveguide 15, the second high frequency power can be propagated to the second waveguide more accurately.
- FIG. 11 relates to a second modification including two quantum circuits 11, two waveguides 12, two high frequency power supplies 13, two auxiliary waveguides 15, and two auxiliary high frequency power supplies 16.
- the quantum circuit system 10b is illustrated, the number of the quantum circuit 11, the waveguide 12, the high frequency power supply 13, the auxiliary waveguide 15, and the auxiliary high frequency power supply 16 is arbitrary.
- FIG. 12 is a diagram showing a configuration of a quantum circuit system 10c according to a third modification of the present embodiment.
- the quantum circuit system 10c according to the third modification is the first quantum circuit 11a and the second quantum circuit 11b having at least two quantum states, respectively, and the first waveguide 12a electromagnetically connected to the first quantum circuit 11a. And a second waveguide 12b electromagnetically connected to the second quantum circuit 11b.
- the quantum circuit system 10c according to the third modification includes a second auxiliary waveguide 15b extending along the second waveguide 12b.
- the second quantum circuit 11b when the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a to a predetermined quantum state, the second quantum circuit 11b A second auxiliary high frequency power supply 16b that propagates the third high frequency power to the second auxiliary waveguide 15b and indirectly propagates the second high frequency power to the second auxiliary waveguide 12b so as to compensate for the change in the quantum state. Be prepared.
- the quantum circuit system 10c according to the third modification is a change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first auxiliary high-frequency power source 16a that propagates high-frequency power to the first auxiliary waveguide 15a and indirectly propagates high-frequency power to the first auxiliary waveguide 12a is provided so as to compensate for the above.
- the first quantum circuit 11a, the second quantum circuit 11b, the first waveguide 12a, the second waveguide 12b, the first high frequency power supply 13a, the second high frequency power supply 13b, and the first A plurality of configurations having the auxiliary waveguide 15a, the second auxiliary waveguide 15b, the first auxiliary high-frequency power supply 16a, and the second auxiliary high-frequency power supply 16b as one unit are arranged side by side.
- the waveguide 12 has the above-mentioned one-unit configuration so that the positions where the high-frequency power supply 13 is provided are opposite to each other with the quantum circuit 11 in between. Are arranged adjacent to each other in a direction orthogonal to the extending direction. With such an arrangement, the area of the substrate on which the plurality of quantum circuits 11 are provided can be efficiently used, and the auxiliary waveguide 15 can compensate for unintended changes in the quantum state of the quantum circuits 11.
- FIG. 12 relates to a third modification including eight quantum circuits 11, eight waveguides 12, eight high frequency power supplies 13, eight auxiliary waveguides 15, and eight auxiliary high frequency power supplies 16.
- the quantum circuit system 10c is illustrated, the number of the quantum circuit 11, the waveguide 12, the high frequency power supply 13, the auxiliary waveguide 15, and the auxiliary high frequency power supply 16 is arbitrary.
- FIG. 13 is a diagram showing a configuration of a quantum circuit system 10d according to a fourth modification of the present embodiment.
- the quantum circuit system 10d according to the fourth modification has a first quantum circuit 11a and a second quantum circuit 11b having at least two quantum states, respectively, and a first waveguide 12a electromagnetically connected to the first quantum circuit 11a. And a second waveguide 12b electromagnetically connected to the second quantum circuit 11b.
- the quantum circuit system 10d according to the fourth modification includes a second auxiliary waveguide 15b extending along the second waveguide 12b.
- the second quantum circuit 11b when the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a into a predetermined quantum state, the second quantum circuit 11b A second auxiliary high frequency power supply 16b that propagates the third high frequency power to the second auxiliary waveguide 15b and indirectly propagates the second high frequency power to the second auxiliary waveguide 12b so as to compensate for the change in the quantum state. Be prepared.
- the quantum circuit system 10d according to the fourth modification is a change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first auxiliary high-frequency power source 16a that propagates high-frequency power to the first auxiliary waveguide 15a and indirectly propagates high-frequency power to the first auxiliary waveguide 12a is provided so as to compensate for the above.
- the first quantum circuit 11a, the second quantum circuit 11b, the first waveguide 12a, the second waveguide 12b, the first high frequency power supply 13a, the second high frequency power supply 13b, and the first A plurality of configurations having the auxiliary waveguide 15a, the second auxiliary waveguide 15b, the first auxiliary high-frequency power supply 16a, and the second auxiliary high-frequency power supply 16b as one unit are arranged side by side.
- the waveguide 12 extends radially, and the position where the high frequency power supply 13 is provided is rotated by 90 ° around the position of the quantum circuit 11 and arranged.
- a plurality of the above-mentioned one-unit configurations are arranged so as to be performed. With such an arrangement, the area of the substrate on which the plurality of quantum circuits 11 are provided can be efficiently used, and the auxiliary waveguide 15 can compensate for unintended changes in the quantum state of the quantum circuits 11.
- FIG. 13 relates to a fourth modification including eight quantum circuits 11, eight waveguides 12, eight high frequency power supplies 13, eight auxiliary waveguides 15, and eight auxiliary high frequency power supplies 16.
- the quantum circuit system 10d is illustrated, the number of the quantum circuit 11, the waveguide 12, the high frequency power supply 13, the auxiliary waveguide 15, and the auxiliary high frequency power supply 16 is arbitrary.
- FIG. 14 is a diagram showing a configuration of a quantum circuit system 10e according to a fifth modification of the present embodiment.
- the quantum circuit system 10e according to the fifth modification is the first quantum circuit 11a and the second quantum circuit 11b having at least two quantum states, respectively, and the first waveguide 12a electromagnetically connected to the first quantum circuit 11a. And a second waveguide 12b electromagnetically connected to the second quantum circuit 11b.
- the quantum circuit system 10e according to the fifth modification includes a second auxiliary waveguide 15b extending along the second waveguide 12b.
- the quantum circuit system 10e according to the fifth modification is a case where the first high frequency power is propagated to the first waveguide 12a to change the first quantum circuit 11a to a predetermined quantum state, and the second quantum circuit 11b A second auxiliary high frequency power supply 16b that propagates the third high frequency power to the second auxiliary waveguide 15b and indirectly propagates the second high frequency power to the second auxiliary waveguide 12b so as to compensate for the change in the quantum state. Be prepared.
- the quantum circuit system 10e according to the fifth modification is a change in the quantum state of the first quantum circuit 11a when the high frequency power is propagated to the second waveguide 12b to change the second quantum circuit 11b to a predetermined quantum state.
- a first auxiliary high-frequency power source 16a that propagates high-frequency power to the first auxiliary waveguide 15a and indirectly propagates high-frequency power to the first auxiliary waveguide 12a is provided so as to compensate for the above.
- the first read line 14a for reading the quantum state of the first quantum circuit 11a and the second read line 14b for reading the quantum state of the second quantum circuit 11b.
- the first readout line 14a may be connected between the input capacitor C in and the gate capacitor C g included in the first quantum circuit 11a via the output capacitor.
- the second readout line 14b may be connected between the input capacitor C in and the gate capacitor C g included in the second quantum circuit 11b via the output capacitor.
- the output capacitor may also serve as the input capacitor C in .
- the first quantum circuit 11a, the second quantum circuit 11b, the first waveguide 12a, the second waveguide 12b, the first high frequency power supply 13a, the second high frequency power supply 13b, and the first A plurality of configurations having the auxiliary waveguide 15a, the second auxiliary waveguide 15b, the first auxiliary high-frequency power supply 16a, and the second auxiliary high-frequency power supply 16b as one unit are arranged side by side.
- the waveguide 12 has the above-mentioned one-unit configuration so that the positions where the high-frequency power supply 13 is provided are opposite to each other with the quantum circuit 11 in between. Are arranged adjacent to each other in a direction orthogonal to the extending direction. With such an arrangement, the area of the substrate on which the plurality of quantum circuits 11 are provided can be efficiently used, and the auxiliary waveguide 15 can compensate for unintended changes in the quantum state of the quantum circuits 11.
- FIG. 14 four quantum circuits 11, four waveguides 12, four high-frequency power supplies 13, four auxiliary waveguides 15, four auxiliary high-frequency power supplies 16, and four readout lines 14 are shown.
- the quantum circuit system 10e according to the fifth modification provided is illustrated, the number of the quantum circuit 11, the waveguide 12, the high frequency power supply 13, the auxiliary waveguide 15, the auxiliary high frequency power supply 16, and the four readout lines 14 is arbitrary. is there.
Abstract
Description
Claims (5)
- 少なくとも2つの量子状態をそれぞれ有する第1量子回路及び第2量子回路と、
前記第1量子回路に電磁気的に接続された第1導波路及び前記第2量子回路に電磁気的に接続された第2導波路と、
前記第1導波路に第1高周波電力を伝搬させて前記第1量子回路を所定の量子状態に変化させる場合に、前記第2量子回路の量子状態の変化を補償するように、直接的又は間接的に、前記第2導波路に第2高周波電力を伝搬させる高周波電源と、
を備える量子回路システム。 A first quantum circuit and a second quantum circuit having at least two quantum states, respectively,
A first waveguide electromagnetically connected to the first quantum circuit and a second waveguide electromagnetically connected to the second quantum circuit.
Directly or indirectly so as to compensate for the change in the quantum state of the second quantum circuit when the first high-frequency power is propagated through the first waveguide to change the first quantum circuit to a predetermined quantum state. A high-frequency power supply that propagates the second high-frequency power to the second waveguide,
Quantum circuit system with. - 前記高周波電源は、前記第1導波路に前記第1高周波電力を伝搬させたタイミング以降に、前記第2量子回路の量子状態の変化を補償するように、直接的又は間接的に、前記第2導波路に前記第2高周波電力を伝搬させる、
請求項1に記載の量子回路システム。 The high-frequency power supply directly or indirectly compensates for the change in the quantum state of the second quantum circuit after the timing at which the first high-frequency power is propagated to the first waveguide. Propagating the second high-frequency power through the waveguide,
The quantum circuit system according to claim 1. - 前記高周波電源は、前記第1導波路に前記第1高周波電力を伝搬させたことによる前記第2量子回路の量子状態の変化を補償する高周波電力と、前記第2量子回路を所定の量子状態に変化させる高周波電力との重ね合わせである前記第2高周波電力を、直接的又は間接的に、前記第2導波路に伝搬させる、
請求項1又は2に記載の量子回路システム。 The high-frequency power supply has high-frequency power that compensates for a change in the quantum state of the second quantum circuit due to propagation of the first high-frequency power to the first waveguide, and brings the second quantum circuit into a predetermined quantum state. The second high-frequency power, which is a superposition with the high-frequency power to be changed, is directly or indirectly propagated to the second waveguide.
The quantum circuit system according to claim 1 or 2. - 前記第2導波路に沿って延伸する補助導波路をさらに備え、
前記高周波電源は、前記第1導波路に前記第1高周波電力を伝搬させて前記第1量子回路を所定の量子状態に変化させる場合に、前記第2量子回路の量子状態の変化を補償するように、前記補助導波路に第3高周波電力を伝搬させ、間接的に、前記第2導波路に前記第2高周波電力を伝搬させる、
請求項1又は2に記載の量子回路システム。 An auxiliary waveguide extending along the second waveguide is further provided.
The high-frequency power supply compensates for the change in the quantum state of the second quantum circuit when the first high-frequency power is propagated to the first waveguide to change the first quantum circuit to a predetermined quantum state. In addition, the third high-frequency power is propagated to the auxiliary waveguide, and indirectly, the second high-frequency power is propagated to the second waveguide.
The quantum circuit system according to claim 1 or 2. - 前記補助導波路は、前記第2導波路に沿って延伸する第1部分及び第2部分と、前記第1部分及び前記第2部分を接続する折返し部分とを含む、
請求項4に記載の量子回路システム。 The auxiliary waveguide includes a first portion and a second portion extending along the second waveguide, and a folded portion connecting the first portion and the second portion.
The quantum circuit system according to claim 4.
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YAN, ZHIGUANG ET AL., SUPPLEMENTARY MATERIALS FOR STRONGLY CORRELATED QUANTUM WALKS WITH A 12-QUBIT SUPERCONDUCTING PROCESSOR, 2 May 2019 (2019-05-02), pages 1 - 35, XP055792923, Retrieved from the Internet <URL:https://science.sciencemag.org/cgi/content/full/science.aaw1611/DC1> [retrieved on 20191010], DOI: 10.1126/science.aaw1611 * |
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