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arXiv 0812.4039cond-mat.supr-con
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具有强非对称动力学参数的dc-SQUID的量子不稳定性

Quantum instability in a dc-SQUID with strongly asymmetric dynamical parameters

A. U. Thomann, V. B. Geshkenbein, G. Blatter

摘要:

一个经典系统在零温度下不能脱离亚稳态。然而,由经典自由度和量子自由度组成的复合系统可以通过一个连续的过程将自己拖出亚稳态。该序列开始于量子分量的隧穿,然后触发保持经典部分的捕获势的扭曲。只要这种畸变足够大,使亚稳态变成不稳定态,经典分量就可以逃逸。这一过程使人想起著名的穆恩希豪森,他讲述了一个故事,说他抓住自己的头发把自己从沼泽地里拉出来,从而使自己免于沉没-因此我们把这种衰变称为“穆恩希豪森效应”。我们表明,这样一个复合系统可以方便地研究和实施的dc-SQUID具有不对称的动力学参数。我们确定该系统的动态相图的各种选择的结参数和系统的准备工作。

英文摘要:

A classical system cannot escape out of a metastable state at zero temperature. However, a composite system made from both classical and quantum degrees of freedom may drag itself out of the metastable state by a sequential process. The sequence starts with the tunneling of the quantum component which then triggers a distortion of the trapping potential holding the classical part. Provided this distortion is large enough to turn the metastable state into an unstable one, the classical component can escape. This process reminds of the famous baron Muenchhausen who told the story of rescuing himself from sinking in a swamp by pulling himself up by his own hair--we thus term this decay the `Muenchhausen effect'. We show that such a composite system can be conveniently studied and implemented in a dc-SQUID featuring asymmetric dynamical parameters. We determine the dynamical phase diagram of this system for various choices of junction parameters and system preparations.

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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