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arXiv 1303.0288cond-mat.str-el
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量子点与正常和超导导线耦合的非平衡输运的量子蒙特卡罗研究

Quantum Monte Carlo study of nonequilibrium transport through a quantum dot coupled to normal and superconducting leads

Akihisa Koga

摘要:

利用弱耦合连续时间蒙特卡罗方法研究了量子点与正常和超导导线耦合的非平衡现象。通过计算量子点上的粒子数、双占据率和对关联随时间的演化,讨论了系统如何接近稳态。我们还推导出了在线性响应区域之外的通过量子点的恒定电流。结果表明,这种相互作用降低了近藤单重态主导区的电流。另一方面,当量子点与超导引线紧密耦合时,电流通过库仑相互作用的引入而增加,库仑相互作用源于近藤效应和邻近效应之间的竞争。瞬态电流引起的相互作用淬火也解决了。

英文摘要:

We investigate the nonequilibrium phenomena through the quantum dot coupled to the normal and superconducting leads using a weak-coupling continuous-time Monte Carlo method. Calculating the time evolution of particle number, double occupancy, and pairing correlation at the quantum dot, we discuss how the system approaches the steady state. We also deduce the steady current through the quantum dot beyond the linear response region. It is clarified that the interaction decreases the current in the Kondo-singlet dominant region. On the other hand, when the quantum dot is tightly coupled to the superconducting lead, the current is increased by the introduction of the Coulomb interaction, which originates from the competition between the Kondo and proximity effects. Transient currents induced by the interaction quench are also addressed.

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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