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

Journal of Physics B Atomic Molecular and Optical Physics

Influence of cavity decay on unconventional geometric quantum phase gates with superconducting quantum-interference-device qubits inside a cavity

Zhengang Shi, Xiongwen Chen, Kehui Song

Published Jan 21, 2009• 2 citations
Publisher

Abstract

We propose a potential scheme for carrying out two-qubit unconventional geometric logic gates on two identical superconducting quantum-interference-device (SQUID) qubits coupled to a single-mode microwave field. The geometric logic gate operation is performed in two lower flux states, and the excited state |2 does not participate in the procedure. The SQUIDs undergo no transitions during gate operation. Thus, the decoherence due to energy spontaneous emission based on the levels of SQUIDs is suppressed. We present the two-qubit unconventional geometric logic gates in both an ideal cavity and a real cavity with decay. Discussions about the fidelity and the success probability of the proposed scheme as well as the experimental feasibility are given in detail.

DOI
10.1088/0953-4075/42/3/035504

Related papers

Unconventional Geometric Phase-Shift Gates Based on Superconducting Quantum Interference Devices Coupled to a Single-Mode Cavity

Kehui Song, Zheng-Wei Zhou, Guo Guang-Can

We present a scheme to realize geometric phase-shift gate for two superconducting quantum interference device (SQUID) qubits coupled to a single-mode microwave field. The geometric phase-shift gate operation is performed in two lower flux states, and the excited state |2⟩ would not participate in the procedure. The SQUIDs undergo no transitions during the gate operation. Thus, the docoherence due to energy spontaneous emission based on the levels of SQUIDs are suppressed. The gate is insensitive to the cavity decay throughout the operation since the cavity mode is displaced along a circle in the phase space, acquiring a phase conditional upon the two lower flux states of the SQUID qubits, and the cavity mode is still in the original vacuum state. Based on the SQUID qubits interacting with the cavity mode, our proposed approach may open promising prospects for quantum logic in SQUID-system.

Communications in Theoretical Physics•Oct 1, 2006•0 citations

Unconventional Geometric Phase Gate with Superconducting Quantum Interference Device Qubits in Cavity QED

Wen‐Xing Yang, Ai-Xi Chen

In the system with superconducting quantum interference devices (SQUID) in cavity, a scheme for constructing two-qubit quantum phase gate via a conventional geometric phase-shift is proposed by using a quantized cavity field and classical microwave pulses. In this scheme, the gate operation is realized in the subspace spanned by the two lower flux states of the SQUID system and the population operator of the excited state has no effect on it. Thus the effect of decoherence caused from the levels of the SQUID system is possible to minimize. Under cavity decay, our strictly numerical simulation shows that it is also possible to realize the unconventional geometric phase gate. The experimental feasibility is discussed in detail.

Communications in Theoretical Physics•Apr 1, 2008•2 citations

Jnconventional Geometric Phase Gate with Superconducting Quantum Interference Device Qubits in Cavity QED

Wen Yang, Chen Ai

In the system with superconducting quantum interference devices (SQUID) in cavity,a scheme for con- structing two-qubit quantum phase gate via a conventional geometric phase-shift is proposed by using a quantized cavity field and classical microwave pulses.In this scheme,the gate operation is realized in the subspace spanned by the two lower flux states of the SQUID system and the population operator of the excited state has no effect on it.Thus the effect of decoherence caused from the levels of the SQUID system is possible to minimize.Under cavity decay,our strictly numerical simulation shows that it is also possible to realize the unconventional geometric phase gate.The experimental feasibility is discussed in detail.

理论物理通讯：英文版•Jan 1, 2008•0 citations

Strong-driving-assisted unconventional geometric logic gate in cavity QED

Changyong Chen, Mang Feng, Xiaolong Zhang +1 more

We propose a potential scheme for carrying out two-qubit unconventional geometric logic gates on two identical three-level atoms in a cavity, strongly driven by a resonant classical field. Compared to a previous scheme [S. B. Zheng, Phys. Rev. A 70, 052320 (2004)] based on the large-detuning interaction of the two identical three-level atoms with the cavity mode, our scheme can, in principle, achieve a faster gating because of the resonant coupling of the atoms to the classical field. We present the two-qubit unconventional geometric phase gates in both an ideal cavity and a real cavity with decay. Discussions about the fidelity and the success probability of the proposed scheme as well as the experimental feasibility are made in detail.

Physical Review A•Mar 30, 2006•61 citations

Quantum logic gate operation and entanglement with superconducting quantum interference devices in a cavity via a Raman transition

Kehui Song, Zheng-Wei Zhou, Guang‐Can Guo

In the system with superconducting quantum interference devices (SQUIDs) in cavity, the quantum logic gates operation and entanglement can be achieved by using a quantized cavity field and classical microwave pluses, via Raman transition. In this scheme, no transfer of quantum information between the SQUIDs and cavity is required, the cavity field is only virtually excited and thus the cavity decay is suppressed during the gate operation and entanglement generations. The gate operation and entanglement generations are realized by using only the two lower flux states of the SQUID system and the excited state would not be excited. Therefore, the effect of docoherence based on the levels of the SQUID system is possible to minimize.

Physical Review A•May 6, 2005•74 citations

Quantum logic gates operation using SQUID qubits in bimodal cavity

Kehui Song

We present a scheme to realize the basic two-qubit logic gates such as the quantum phase gate and SWAP gate using a detuned microwave cavity interacting with three-level superconducting-quantum-interference-device (SQUID) qubit(s), by placing SQUID(s) in a two-mode microwave cavity and using adiabatic passage methods. In this scheme, the two logical states of the qubit are represented by the two lowest levels of the SQUID and the cavity fields are treated as quantized. Compared with the previous method, the complex procedures of adjusting the level spacing of the SQUID and applying the resonant microwave pulse to the SQUID to create transformation are not required. Based on superconducting device with relatively long decoherence time and simplified operation procedure, the gates operate at a high speed, which is important in view of decoherence.

Chinese Physics•Jan 16, 2006•17 citations
We propose a potential scheme for carrying out two-qubit unconventional geometric logic gates on two identical superconducting quantum-interference-device (SQUID) qubits coupled to a single-mode microwave field. The geometric logic gate operation is performed in two lower flux states, and the excited state |2 does not participate in the procedure. The SQUIDs undergo no transitions during gate operation. Thus, the decoherence due to energy spontaneous emission based on the levels of SQUIDs is suppressed. We present the two-qubit unconventional geometric logic gates in both an ideal cavity and a real cavity with decay. Discussions about the fidelity and the success probability of the proposed scheme as well as the experimental feasibility are given in detail.
We present a scheme to realize geometric phase-shift gate for two superconducting quantum interference device (SQUID) qubits coupled to a single-mode microwave field. The geometric phase-shift gate operation is performed in two lower flux states, and the excited state |2⟩ would not participate in the procedure. The SQUIDs undergo no transitions during the gate operation. Thus, the docoherence due to energy spontaneous emission based on the levels of SQUIDs are suppressed. The gate is insensitive to the cavity decay throughout the operation since the cavity mode is displaced along a circle in the phase space, acquiring a phase conditional upon the two lower flux states of the SQUID qubits, and the cavity mode is still in the original vacuum state. Based on the SQUID qubits interacting with the cavity mode, our proposed approach may open promising prospects for quantum logic in SQUID-system.
In the system with superconducting quantum interference devices (SQUID) in cavity, a scheme for constructing two-qubit quantum phase gate via a conventional geometric phase-shift is proposed by using a quantized cavity field and classical microwave pulses. In this scheme, the gate operation is realized in the subspace spanned by the two lower flux states of the SQUID system and the population operator of the excited state has no effect on it. Thus the effect of decoherence caused from the levels of the SQUID system is possible to minimize. Under cavity decay, our strictly numerical simulation shows that it is also possible to realize the unconventional geometric phase gate. The experimental feasibility is discussed in detail.
In the system with superconducting quantum interference devices (SQUID) in cavity,a scheme for con- structing two-qubit quantum phase gate via a conventional geometric phase-shift is proposed by using a quantized cavity field and classical microwave pulses.In this scheme,the gate operation is realized in the subspace spanned by the two lower flux states of the SQUID system and the population operator of the excited state has no effect on it.Thus the effect of decoherence caused from the levels of the SQUID system is possible to minimize.Under cavity decay,our strictly numerical simulation shows that it is also possible to realize the unconventional geometric phase gate.The experimental feasibility is discussed in detail.
We propose a potential scheme for carrying out two-qubit unconventional geometric logic gates on two identical three-level atoms in a cavity, strongly driven by a resonant classical field. Compared to a previous scheme [S. B. Zheng, Phys. Rev. A 70, 052320 (2004)] based on the large-detuning interaction of the two identical three-level atoms with the cavity mode, our scheme can, in principle, achieve a faster gating because of the resonant coupling of the atoms to the classical field. We present the two-qubit unconventional geometric phase gates in both an ideal cavity and a real cavity with decay. Discussions about the fidelity and the success probability of the proposed scheme as well as the experimental feasibility are made in detail.
In the system with superconducting quantum interference devices (SQUIDs) in cavity, the quantum logic gates operation and entanglement can be achieved by using a quantized cavity field and classical microwave pluses, via Raman transition. In this scheme, no transfer of quantum information between the SQUIDs and cavity is required, the cavity field is only virtually excited and thus the cavity decay is suppressed during the gate operation and entanglement generations. The gate operation and entanglement generations are realized by using only the two lower flux states of the SQUID system and the excited state would not be excited. Therefore, the effect of docoherence based on the levels of the SQUID system is possible to minimize.
We present a scheme to realize the basic two-qubit logic gates such as the quantum phase gate and SWAP gate using a detuned microwave cavity interacting with three-level superconducting-quantum-interference-device (SQUID) qubit(s), by placing SQUID(s) in a two-mode microwave cavity and using adiabatic passage methods. In this scheme, the two logical states of the qubit are represented by the two lowest levels of the SQUID and the cavity fields are treated as quantized. Compared with the previous method, the complex procedures of adjusting the level spacing of the SQUID and applying the resonant microwave pulse to the SQUID to create transformation are not required. Based on superconducting device with relatively long decoherence time and simplified operation procedure, the gates operate at a high speed, which is important in view of decoherence.