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arXiv quant-ph/0407185quant-phcond-mat.mes-hallhep-ph
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具有退相干的宏观量子隧穿

Macroscopic quantum tunneling with decoherence

Esteban Calzetta, Enric Verdaguer

摘要:

计算了一个模拟宏观量子隧穿的系统的隧穿几率。考虑一个单自由度的开放量子系统,它由一个囚禁在立方势中的粒子与一个具有耗散和扩散参数的环境相互作用组成。基于孤立系的能量本征函数,提出了一种新的表示方法. e.系统与环境的非耦合,用于写出开放量子系统的约化Wigner函数的动力学主方程。在这种表示中,这个方程变得非常简单。使用的WKB近似的本征函数建议的近似,允许的隧道速率的分析计算,在这个实时的形式主义,当系统最初被困在假基态。我们发现由环境产生的退相干抑制隧穿与其他具有不同势的宏观量子系统中的结果一致。我们面对我们的分析预测与实验中的逃逸率从零电压状态的电流偏置约瑟夫森结分流电阻测量。

英文摘要:

The tunneling probability for a system modelling macroscopic quantum tunneling is computed. We consider an open quantum system with one degree of freedom consisting of a particle trapped in a cubic potential interacting with an environment characterized by a dissipative and a diffusion parameter. A representation based on the energy eigenfunctions of the isolated system, i. e. the system uncoupled to the environment, is used to write the dynamical master equation for the reduced Wigner function of the open quantum system. This equation becomes very simple in that representation. The use of the WKB approximation for the eigenfunctions suggests an approximation which allows an analytic computation of the tunneling rate, in this real time formalism, when the system is initially trapped in the false ground state. We find that the decoherence produced by the environment suppresses tunneling in agreement with results in other macroscopic quantum systems with different potentials. We confront our analytical predictions with an experiment where the escape rate from the zero voltage state was measured for a current-biased Josephson junction shunted with a resistor.

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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