Quasiclassical Theory of Spin Imbalance in a Normal Metal-Superconductor Heterostructure with a Spin-Active Interface

27th International Conference on Low Temperature Physics

Shevtsov, O.^1 ; Löfwander, T.^1

Department of Microtechnology and Nanoscience-MC2, Chalmers University of Technology, Göteborg

SE-412 96, Sweden^1

关键词: Andreev bound state;    Charge imbalance;    Density separation;    External magnetic field;    Non-equilibrium magnetization;    Non-equilibrium phenomena;    Non-local measurement;    Quasiclassical theory;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/2/022044/pdf
DOI  :  10.1088/1742-6596/568/2/022044

来源: IOP

【 摘 要 】

Non-equilibrium phenomena in superconductors have attracted much attention since The first experiments on charge imbalance in The early 1970's. Nowadays a new promising line of research lies at an intersection between superconductivity and spintronics. Here we develop a quasiclassical theory of a single junction between a normal metal and a superconductor with a spin-active interface at finite bias voltages. Due to spin-mixing and spin-filtering effects of The interface a non-equilibrium magnetization (or spin imbalance) is induced at The superconducting side of The junction, which relaxes to zero in The bulk. A peculiar feature of The system is The presence of interface-induced Andreev bound states, which influence The magnitude and The decay length of spin imbalance. Recent experiments on spin and charge density separation in superconducting wires required external magnetic field for observing a spin signal via non-local measurements. Here, we propose an alternative way to observe spin imbalance without applying magnetic field.