Nonequilibrium spin transport in Zeeman-split superconductors

Article

关键词: CHARGE SEPARATION;    QUASI-PARTICLE;    RELAXATION;    LIFETIMES;    IMBALANCE;   

DOI  :  10.1103/PhysRevB.91.121407

来源: SCIE

【 摘 要 】

We investigate theoretically the nonlocal conductance through a superconducting wire in tunnel contact with normal and ferromagnetic leads. In the presence of an in-plane magnetic field, the superconducting density of states is spin split, and the current injected from the normal lead is spin polarized. A nonlocal conductance that is antisymmetric with the applied voltage can be measured with a ferromagnetic lead. It persists for a distance between the contacts that is larger than both the charge-imbalance relaxation length and the normal-state spin relaxation length. We determine its amplitude by considering two extreme models of weak and strong internal equilibration of the superconducting quasiparticles due to electron-electron interactions. We find that the nonlocal signal, which was measured in recent experiments and discussed as a spin-imbalance effect, can be interpreted alternatively as the signature of a thermoelectric effect.

【 授权许可】

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