Method and Circuit for Implementing Two-Qubit Gate, Quantum Device, and Quantum Chip
Disclosed are a method and a circuit for implementing a two-qubit gate, a quantum device, and a quantum chip. The method includes: applying a first quantum control signal to a first data qubit; applying a second quantum control signal to a second data qubit; and activating, by means of adjusting the first quantum control signal and the second quantum control signal, longitudinal coupling between the first data qubit and the second data qubit within a predetermined time, so as to implement the two-qubit gate. The present disclosure solves the technical problem in the related art of low precision of the two-qubit gate.
1 . A method for implementing a two-qubit gate, comprising:
applying a first quantum control signal to a first data qubit;
applying a second quantum control signal to a second data qubit; and
activating, by means of adjusting the first quantum control signal and the second quantum control signal, longitudinal coupling between the first data qubit and the second data qubit within a predetermined time, so as to implement the two-qubit gate.
2 . The method as claimed in claim 1 , wherein the first quantum control signal and the second quantum control signal are control signals of the same type, and an amplitude of the first quantum control signal is a fixed multiple of an amplitude of the second quantum control signal.
3 . The method as claimed in claim 1 , further comprising:
controlling, by means of adjusting the first quantum control signal and the second quantum control signal, other coupling between the first data qubit and the second data qubit to be minimum, wherein the other coupling is coupling other than the longitudinal coupling.
4 . The method as claimed in claim 1 , wherein the first data qubit is a first Fluxonium qubit, and the second data qubit is a second Fluxonium qubit.
5 . The method as claimed in claim 4 , wherein before applying the first quantum control signal to the first data qubit and applying the second quantum control signal to the second data qubit, the method further comprises:
adjusting the first data qubit and the second data qubit to be in a flux sweet spot state, wherein the flux sweet spot state is that decoherence time of a data qubit reaches a maximum value.
6 . The method as claimed in claim 1 , wherein the first quantum control signal and the second quantum control signal are hyperbolic tangent pulse signals.
7 . A circuit for implementing a two-qubit gate, comprising: a first data qubit, a second data qubit, a first signal generator, a second signal generator, and a signal controller, wherein,
the first signal generator is configured to generate a first quantum control signal and apply the first quantum control signal to the first data qubit;
the second signal generator is configured to generate a second quantum control signal and apply the second quantum control signal to the second data qubit; and
the signal controller is configured to activate, by means of controlling the first signal generator to adjust the first quantum control signal and controlling the second signal generator to adjust the second quantum control signal, longitudinal coupling between the first data qubit and the second data qubit within a predetermined time, so as to implement the two-qubit gate.
8 . The circuit as claimed in claim 7 , wherein the signal controller comprises: a scanner and an adjuster, wherein,
the scanner is configured to scan other coupling between the first data qubit and the second data qubit to obtain other coupling results, wherein the other coupling is coupling other than the longitudinal coupling; and
the adjuster is configured to control, by means of controlling the first signal generator to adjust the first quantum control signal and controlling the second signal generator to adjust the second quantum control signal, the other coupling between the first data qubit and the second data qubit to be minimal based on the other coupling results.
9 . The circuit as claimed in claim 7 , wherein the first data qubit is a first Fluxonium qubit, and the second data qubit is a second Fluxonium qubit.
10 . The circuit as claimed in claim 9 , wherein the first Fluxonium qubit and the second Fluxonium qubit achieve mutual inductance through independent inductors.
11 . The circuit as claimed in claim 9 , wherein the first Fluxonium qubit and the second Fluxonium qubit achieve mutual inductance through a shared inductor.
12 . The circuit as claimed in claim 7 , wherein the two-qubit gate is a controlled phase CZ gate.
13 . A quantum device, comprising the circuit for implementing a two-qubit gate, the circuit being configured to perform a logic gate operation on a target data qubit to be processed in the quantum device, wherein the two-qubit gate comprises:
a first data qubit, a second data qubit, a first signal generator, a second signal generator, and a signal controller, wherein,
the first signal generator is configured to generate a first quantum control signal and apply the first quantum control signal to the first data qubit;
the second signal generator is configured to generate a second quantum control signal and apply the second quantum control signal to the second data qubit; and
the signal controller is configured to activate, by means of controlling the first signal generator to adjust the first quantum control signal and controlling the second signal generator to adjust the second quantum control signal, longitudinal coupling between the first data qubit and the second data qubit within a predetermined time, so as to implement the two-qubit gate.
14 . (canceled)
15 . The quantum device as claimed in claim 13 , wherein the signal controller comprises: a scanner and an adjuster, wherein,
the scanner is configured to scan other coupling between the first data qubit and the second data qubit to obtain other coupling results, wherein the other coupling is coupling other than the longitudinal coupling; and
the adjuster is configured to control, by means of controlling the first signal generator to adjust the first quantum control signal and controlling the second signal generator to adjust the second quantum control signal, the other coupling between the first data qubit and the second data qubit to be minimal based on the other coupling results.
16 . The circuit as claimed in claim 13 , wherein the first data qubit is a first Fluxonium qubit, and the second data qubit is a second Fluxonium qubit.
17 . The circuit as claimed in claim 16 , wherein the first Fluxonium qubit and the second Fluxonium qubit achieve mutual inductance through independent inductors.
18 . The circuit as claimed in claim 16 , wherein the first Fluxonium qubit and the second Fluxonium qubit achieve mutual inductance through a shared inductor.
19 . The circuit as claimed in claim 13 , wherein the two-qubit gate is a controlled phase CZ gate.