中国物理B ›› 2008, Vol. 17 ›› Issue (2): 440-444.doi: 10.1088/1674-1056/17/2/016

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Relation between quantum NOT gate speed and asymmetry of the potential of RF-SQUID

蔡十华1, 胡菊菊1, 嵇英华2   

  1. (1)Department of Physics, Jiangxi Normal University, Nanchang 330022, China; (2)Department of Physics, Jiangxi Normal University, Nanchang 330022, China;Key Laboratory of Optoelectronic & Telecommunication of Jiangxi, Nanchang, 330022, China
  • 收稿日期:2007-02-26 修回日期:2007-05-29 出版日期:2008-02-20 发布日期:2008-02-20
  • 基金资助:
    Project supported by the Science and Technology Research Foundation of the Education Department of Jiangxi Province, China (Grant No 200592).

Relation between quantum NOT gate speed and asymmetry of the potential of RF-SQUID

Ji Ying-Hua(嵇英华)a)b), Cai Shi-Hua(蔡十华)a, and Hu Ju-Ju(胡菊菊)a)   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330022, China; b Key Laboratory of Optoelectronic & Telecommunication of Jiangxi, Nanchang, 330022, China
  • Received:2007-02-26 Revised:2007-05-29 Online:2008-02-20 Published:2008-02-20
  • Supported by:
    Project supported by the Science and Technology Research Foundation of the Education Department of Jiangxi Province, China (Grant No 200592).

摘要: This paper investigates the relationship between the speed of a quantum not gate and the asymmetry of the potential in an interactive system formed by a two-level RF-SQUID qubit and a classical microwave pulse. The RF-SQUID is characterized by an asymmetric double well potential which gives rise to diagonal matrix elements that describe the interaction of the SQUID with the microwave pulse. And the diagonal matrix elements account for the interaction of the microwave pulse with the SQUID. The results indicate that, when the angular frequency of the microwave field is chosen as near resonate with the transition $\left| 0 \right\rangle \leftrightarrow \left| 1 \right\rangle$, i.e. $\omega_1-\omega_0 \approx \omega_{\rm m}$, (1) the gate speed is decided by three factors, the Rabi frequency, the difference of the diagonal matrix elements between the two levels, and the angular frequency of the applied microwave pulse $\omega _{\rm m} $; (2) the gate speed descends when the asymmetry of the potential is considered.

关键词: gate speed, asymmetry, microwave pulse, RF-SQUID

Abstract: This paper investigates the relationship between the speed of a quantum not gate and the asymmetry of the potential in an interactive system formed by a two-level RF-SQUID qubit and a classical microwave pulse. The RF-SQUID is characterized by an asymmetric double well potential which gives rise to diagonal matrix elements that describe the interaction of the SQUID with the microwave pulse. And the diagonal matrix elements account for the interaction of the microwave pulse with the SQUID. The results indicate that, when the angular frequency of the microwave field is chosen as near resonate with the transition $\left| 0 \right\rangle \leftrightarrow \left| 1 \right\rangle$, i.e. $\omega_1-\omega_0 \approx \omega_{\rm m}$, (1) the gate speed is decided by three factors, the Rabi frequency, the difference of the diagonal matrix elements between the two levels, and the angular frequency of the applied microwave pulse $\omega _{\rm m} $; (2) the gate speed descends when the asymmetry of the potential is considered.

Key words: gate speed, asymmetry, microwave pulse, RF-SQUID

中图分类号:  (Superconducting quantum interference devices (SQUIDs))

  • 85.25.Dq
85.25.Am (Superconducting device characterization, design, and modeling)