三结磁通量子比特中处于亚稳态粒子的热逃逸和量子隧穿

J4 ›› 2012, Vol. 29 ›› Issue (6): 723-728.

三结磁通量子比特中处于亚稳态粒子的热逃逸和量子隧穿

史强,闫珂柱,王晓丽,刘志泉

曲阜师范大学物理工程学院，山东曲阜 273165

收稿日期:2012-01-09 修回日期:2012-02-13 出版日期:2012-11-28 发布日期:2014-03-20
通讯作者: 闫珂柱（1950-）山东人，教授，从事量子信息和玻色爱因斯坦凝聚方面的理论研究。 E-mail:yankezhu@126.com
作者简介:史强（1986-）山东人，研究生，从事量子信息理论的研究。E-mail:s1986q@126.com.
基金资助:
国家自然科学基金（11047006）资助项目

Thermal escape and macroscopic quantum tunneling from metastable state in three-junction flux qubit

Shi Qiang, Yan Kezhu, Wang Xiaoli, Liu Zhiquan

College of Physics and Engineering, Qufu Normal University, Qufu 273165, China

Received:2012-01-09 Revised:2012-02-13 Published:2012-11-28 Online:2014-03-20

摘要/Abstract

摘要：

运用热力学统计中Kramers理论和Wentzel-Kramers-Brillouin(WKB)近似理论，分析了三结磁通量子比特中处于亚稳态粒子的热逃逸和量子隧穿逃逸。在0.01K到4.2K温度下，计算出了粒子的逃逸率，得到了跳变磁通随磁场和温度变化的分布规律，并同两结超导干涉仪的分布规律进行了定量比较。结果显示，三结磁通量子比特自身噪声比两结超导干涉仪大。

关键词: 量子信息, 磁通量子比特, 亚稳态, 约瑟夫森结

Abstract:

With Kramers theory and Wentzel-Kramers-Brillouin (WKB) approximation theory, this research investigates the thermal escape and macroscopic quantum tunneling behavior of the metastable state in a three-junction flux qubit. At temperature ranging from 0.01k to 4.2k, the escape rate is calculated, the switching distribution which varies with magnetic field and temperature is worked out and the case of superconducting interferometer is also compared quantitatively. The results show that self-noise of three-junction flux qubit is bigger than that of superconducting interferometer.

Key words: quantum information, flux qubit, metastable state, Josephson junction

中图分类号:

O413.1
O511

史强闫珂柱王晓丽刘志泉. 三结磁通量子比特中处于亚稳态粒子的热逃逸和量子隧穿[J]. J4, 2012, 29(6): 723-728.

Shi Qiang, Yan Kezhu, Wang Xiaoli, Liu Zhiquan. Thermal escape and macroscopic quantum tunneling from metastable state in three-junction flux qubit[J]. J4, 2012, 29(6): 723-728.

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