Quasiparticle trapping, Andreev level population dynamics, and charge imbalance in superconducting weak links
Quasiparticle trapping, Andreev level population dynamics, and charge imbalance in superconducting weak links
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DOI：
10.1103/physrevb.90.104508
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发表时间：
2014-07
影响因子：
3.7
通讯作者：
A. Zazunov;A. Brunetti;A. Yeyati;R. Egger
中科院分区：
文献类型：
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作者：
A. Zazunov;A. Brunetti;A. Yeyati;R. Egger
我们给出了超导弱链中Andreev束缚态布居数动力学的综合理论框架。与以前的工作相反，我们的方法以一种自洽的方式考虑了连续体准粒子态的非平衡分布。作为我们理论的应用，我们证明了超导接触与环境相涨落的耦合导致了连续介质准粒子布居的电荷不平衡。这种不平衡是由于连续体准粒子和Andreev束缚态系统的速率的左右对称性被打破，并在环形几何中的约瑟夫森电流之上产生准粒子电流。对于模型参数的实际选择，我们评估了准粒子电流的相依性。我们的理论还允许人们分析系统从任意初始态开始的量子相干演化。
We present a comprehensive theoretical framework for the Andreev bound state population dynamics in superconducting weak links. Contrary to previous works, our approach takes into account the generated nonequilibrium distribution of the continuum quasiparticle states in a self-consistent way. As application of our theory, we show that the coupling of the superconducting contact to environmental phase fluctuations induces a charge imbalance of the continuum quasiparticle population. This imbalance is due to the breaking of the left-right symmetry in the rates connecting continuum quasiparticles and the Andreev bound state system, and causes a quasiparticle current on top of the Josephson current in a ring geometry. We evaluate the phase dependence of the quasiparticle current for realistic choices of the model parameters. Our theory also allows one to analyze the quantum coherent evolution of the system from an arbitrary initial state.