Interaction effects on quantum transport in superconducting nanoscale junctions

超导纳米级结中量子传输的相互作用效应

• 批准号: 171454232
• 负责人: Professor Dr. Reinhold Egger
• 金额: --
• 依托单位: Lehrstuhl IV: Theoretische Festkörperphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/171454232?language=en
• 关键词: Interaction; effects; quantum; transport; superconducting

We propose to theoretically study the equilibrium Josephson current-phase relation and the nonequilibrium current-voltage characteristics for various models of interacting quantum dots attached to a pair of superconducting electrodes (Josephson dot). The interplay between superconducting correlations (proximityinduced by the attached electrodes) and the interactions (either Coulomb or vibrational mode interactions) in such Josephson dots gives rise to rich and experimentally accessible physics. In particular, we plan to address: (i) effects due to the spin-orbit coupling, including the spontaneously broken time reversal symmetry; (ii) the nonequilibrium dynamics of a Josephson dot coupled to a two-level system, including the possibility of artificial Kondo screening by Cooper pairs and the backaction of the Cooper pair dynamics on the two-level system, and (iii) the effects of an enlarged SU(4) symmetry on the Josephson effect and the corresponding phase diagram realized in ultraclean carbon nanotubes. We will use both analytical methods (path-integral based field theory and diagrammatic perturbation theory) and quantum Monte Carlo simulations.

本文从理论上研究了超导电极上相互作用量子点（Josephson点）的平衡态电流-相位关系和非平衡态电流-电压特性。超导关联（由连接的电极引起的邻近性）和这种约瑟夫森点中的相互作用（库仑或振动模式相互作用）之间的相互作用产生了丰富的和实验上可获得的物理学。特别是，我们计划解决：（i）由于自旋轨道耦合的影响，包括自发破缺的时间反演对称性;（ii）耦合到二能级系统的Josephson点的非平衡动力学，包括库珀对的人工Kondo屏蔽的可能性和库珀对动力学对二能级系统的反作用，以及（iii）SU（4）对称性对超净碳纳米管中约瑟夫森效应和相应相图的影响。我们将使用两种分析方法（基于路径积分的场论和图解微扰理论）和量子蒙特卡罗模拟。

项目成果

Supercurrent blockade in Josephson junctions with a Majorana wire

• DOI: 10.1103/physrevb.85.104514
• 发表时间: 2012-02
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: A. Zazunov;R. Egger

Anomalous Josephson current, incipient time-reversal symmetry breaking, and Majorana bound states in interacting multilevel dots

• DOI: 10.1103/physrevb.88.144515
• 发表时间: 2013-10-25
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Brunetti, Aldo;Zazunov, Alex;Egger, Reinhold
• 通讯作者: Egger, Reinhold

Quasiparticle trapping, Andreev level population dynamics, and charge imbalance in superconducting weak links

• DOI: 10.1103/physrevb.90.104508
• 发表时间: 2014-07
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: A. Zazunov;A. Brunetti;A. Yeyati;R. Egger