Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Communications in Theoretical Physics

Simple Scheme for Realizing the General Conditional Phase Shift Gate and a Simulation of Quantum Fourier Transform in Circuit QED

Chun-Wang Wu, Yang Han, Zhi-Jiao Deng, Hongyi Li, Ping‐Xing Chen, Cheng-Zu Li

Published Sep 1, 2011• 0 citations
Publisher

Abstract

We propose a theoretical scheme for realizing the general conditional phase shift gate of charge qubits situated in a high-Q superconducting transmission line resonator. The phase shifting angle can be tuned from 0 to 2π by simply adjusting the qubit-resonator detuning and the interaction time. Based on this gate proposal, we give a detailed procedure to implement the three-qubit quantum Fourier transform with circuit quantum electrodynamics (QED). A careful analysis of the decoherence sources shows that the algorithm can be achieved with a high fidelity using current circuit QED techniques.

DOI
10.1088/0253-6102/56/3/07

Related papers

Implementation of a Quantum Conditional Phase Gate for the Quantum Fourier Transform in Circuit QED

Long-Bao Yu, Zheng‐Yuan Xue

It is well known that multiple superconducting charge qubits coupled to a transmission line resonator can be controlled to achieve quantum logic gates between two arbitrary qubits. We propose a scheme to realize a quantum conditional phase gate with a geometric property by circuit electrodynamics, and it is applied naturally to realize the quantum Fourier transform with high fidelity. It is also demonstrated that the application is feasible and considerable under the present experimental technology.

Chinese Physics Letters•Jul 1, 2010•3 citations

Simplified proposal for realizing a multiqubit tunable phase gate in circuit QED

Wenan Li, Yuan Chen

We propose a scheme to realize a multiqubit tunable phase gate in a circuit QED setup where two resonators, each coupling with a qudit, are interconnected to a common qudit (d=4). In this proposal, only two levels of each qudit serve as the logical states and the other two levels are used for the gate realization. The proposal is efficient and simple because only a classical microwave pulse is needed, no matter how many qudits are involved, which significantly reduces experimental difficulty. In a nonresonant case, the tunable phase gate can be achieved readily, while under the resonant condition, a π-phase gate can be realized after a full cycle of Rabi oscillation where the gate speed is rather fast due to the resonant interaction. We have shown that the resulting effective dynamics allows for the creation of a high-fidelity phase gate. The influence of various decoherence processes such as the decay of the resonator mode and the relaxation of the qudits is investigated. Moreover, the proposed scheme can be easily generalized to realize an N-qubit phase gate.

arXiv:1702.08448•Journal of the Optical Society of America B•Jun 29, 2017•2 citations

Fast quantum phase gate in a small-detuning circuit QED model

Chun-Wang Wu, Han Yang, Hongyi Li +3 more

We propose a theoretical protocol for a quantum phase gate between two transmon qubits capacitively coupled to a superconducting transmission line resonator driven by a strong microwave field. Compared with previous protocols involving a dispersive regime, our protocol works at a small detuning, $\ensuremath{\Delta}~g$, and the nontrivial two-qubit gates can be realized in a short time, $~$$1/g$, where $g$ is the qubit-resonator coupling strength. Our analysis shows that the protocol is robust against the main decoherence sources and unavoidable parameter variations. Moreover, our protocol can be implemented using the current experimental design of circuit QED.

Physical Review A•Jul 23, 2010•19 citations

Quantum State Transfer between Charge and Flux Qubits in Circuit-QED

WU Qin-Qin, Jie‐Qiao Liao, Kuang Le-Man

We propose a scheme to implement quantum state transfer in a hybrid circuit quantum electrodynamics (QED) system which consists of a superconducting charge qubit, a flux qubit, and a transmission line resonator (TLR). It is shown that quantum state transfer between the charge qubit and the flux qubit can be realized by using the TLR as the data bus.

Chinese Physics Letters•Apr 1, 2008•19 citations

Shortcut-based quantum gates on superconducting qubits in circuit QED*

Zheng‐Yin Zhao, Run‐Ying Yan, Zhi‐Bo Feng

Construction of optimal gate operations is significant for quantum computation. Here an efficient scheme is proposed for performing shortcut-based quantum gates on superconducting qubits in circuit quantum electrodynamics (QED). Two four-level artificial atoms of Cooper-pair box circuits, having sufficient level anharmonicity, are placed in a common quantized field of circuit QED and are driven by individual classical microwaves. Without the effect of cross resonance, one-qubit NOT gate and phase gate in a decoupled atom can be implemented using the invariant-based shortcuts to adiabaticity. With the assistance of cavity bus, a one-step SWAP gate can be obtained within a composite qubit-photon-qubit system by inversely engineering the classical drivings. We further consider the gate realizations by adjusting the microwave fields. With the accessible decoherence rates, the shortcut-based gates have high fidelities. The present strategy could offer a promising route towards fast and robust quantum computation with superconducting circuits experimentally.

Chinese Physics B•Mar 1, 2021•5 citations

Unconventional Geometric Quantum Gate in Circuit QED

Zheng Xiao-Hu, Jun Dong, Yuwen Liu +2 more

We propose a scheme to implement an unconventional geometric phase gate in circuit QED, i.e. two superconducting charge qubits inside a superconducting transmission line resonator. The quantum operation depends only on global geometric features, and thus is insensitive to the state of the cavity mode.

Chinese Physics Letters•Jul 1, 2010•0 citations
We propose a theoretical scheme for realizing the general conditional phase shift gate of charge qubits situated in a high-Q superconducting transmission line resonator. The phase shifting angle can be tuned from 0 to 2π by simply adjusting the qubit-resonator detuning and the interaction time. Based on this gate proposal, we give a detailed procedure to implement the three-qubit quantum Fourier transform with circuit quantum electrodynamics (QED). A careful analysis of the decoherence sources shows that the algorithm can be achieved with a high fidelity using current circuit QED techniques.
It is well known that multiple superconducting charge qubits coupled to a transmission line resonator can be controlled to achieve quantum logic gates between two arbitrary qubits. We propose a scheme to realize a quantum conditional phase gate with a geometric property by circuit electrodynamics, and it is applied naturally to realize the quantum Fourier transform with high fidelity. It is also demonstrated that the application is feasible and considerable under the present experimental technology.
We propose a scheme to realize a multiqubit tunable phase gate in a circuit QED setup where two resonators, each coupling with a qudit, are interconnected to a common qudit (d=4). In this proposal, only two levels of each qudit serve as the logical states and the other two levels are used for the gate realization. The proposal is efficient and simple because only a classical microwave pulse is needed, no matter how many qudits are involved, which significantly reduces experimental difficulty. In a nonresonant case, the tunable phase gate can be achieved readily, while under the resonant condition, a π-phase gate can be realized after a full cycle of Rabi oscillation where the gate speed is rather fast due to the resonant interaction. We have shown that the resulting effective dynamics allows for the creation of a high-fidelity phase gate. The influence of various decoherence processes such as the decay of the resonator mode and the relaxation of the qudits is investigated. Moreover, the proposed scheme can be easily generalized to realize an N-qubit phase gate.
We propose a theoretical protocol for a quantum phase gate between two transmon qubits capacitively coupled to a superconducting transmission line resonator driven by a strong microwave field. Compared with previous protocols involving a dispersive regime, our protocol works at a small detuning, $\ensuremath{\Delta}~g$, and the nontrivial two-qubit gates can be realized in a short time,  ~ 1/g1/g1/g, where ggg is the qubit-resonator coupling strength. Our analysis shows that the protocol is robust against the main decoherence sources and unavoidable parameter variations. Moreover, our protocol can be implemented using the current experimental design of circuit QED.
Construction of optimal gate operations is significant for quantum computation. Here an efficient scheme is proposed for performing shortcut-based quantum gates on superconducting qubits in circuit quantum electrodynamics (QED). Two four-level artificial atoms of Cooper-pair box circuits, having sufficient level anharmonicity, are placed in a common quantized field of circuit QED and are driven by individual classical microwaves. Without the effect of cross resonance, one-qubit NOT gate and phase gate in a decoupled atom can be implemented using the invariant-based shortcuts to adiabaticity. With the assistance of cavity bus, a one-step SWAP gate can be obtained within a composite qubit-photon-qubit system by inversely engineering the classical drivings. We further consider the gate realizations by adjusting the microwave fields. With the accessible decoherence rates, the shortcut-based gates have high fidelities. The present strategy could offer a promising route towards fast and robust quantum computation with superconducting circuits experimentally.