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arXiv 1010.2804quant-phcond-mat.mes-hallcond-mat.supr-con
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多能隙超导约瑟夫森结中的宏观量子隧穿:通过约瑟夫森-莱格特模的量子涨落增强逃逸率

Macroscopic quantum tunneling in multigap superconducting Josephson junctions: Escape rate enhancement via quantum fluctuations of Josephson-Leggett mode

Yukihiro Ota, Masahiko Machida, Tomio Koyama

摘要:

本文从理论上研究了单能隙超导体和多能隙超导体(如${MgB}_{2}$和铁基超导体)形成的异质约瑟夫森结中的宏观量子隧穿(MQT)。在这种约瑟夫森结中,限定了多于一个的相位差。我们阐明了相位差的量子动力学,并建立了多能隙约瑟夫森结中MQT的理论。相位差的动力学受到约瑟夫森-莱格特模式的强烈影响,该模式是相位差的异相振荡模式。逃逸率是根据约瑟夫森-莱格特模式重整化的有效作用量计算的。结果表明,当约瑟夫森-莱格特模的频率小于约瑟夫森等离子体频率时,逃逸率大大增强。

英文摘要:

We theoretically study the macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap one such as ${MgB}_{2}$ and iron-based superconductors. In such a Josephson junction more than one phase differences are defined. We clarify the quantum dynamics of the phase differences and construct a theory for the MQT in the multi-gap Josephson junctions. The dynamics of the phase differences are strongly affected by the Josephson-Leggett mode, which is the out-of-phase oscillation mode of the phase differences. The escape rate is calculated in terms of the effective action renormalized by the Josephson-Leggett mode. It is shown that the escape rate is drastically enhanced when the frequency of the Josephson-Leggett mode is less than the Josephson-plasma frequency.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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