Spintronics with NSN junction of one-dimensional quantum wires: A study of pure spin current and magnetoresistance

¹  Department of Condensed Matter Physics, Weizmann Institute of Science - Rehovot 76 100, Israel
²  Harish-Chandra Research Institute - Chhatnag Road, Jhusi, Allahabad 211 019, India

Received: 27 October 2007
Accepted: 30 January 2008

Abstract

We demonstrate possible scenarios for production of pure spin current and large tunnelling magnetoresistance ratios from elastic co-tunnelling and crossed Andreev reflection across a superconducting junction comprising of normal-metalsuperconductornormal-metal, where, the normal metal is a one-dimensional interacting quantum wire. We show that there are fixed points in the theory which correspond to the case of pure spin current. We analyze the influence of electron-electron interaction and see how it stabilizes or de-stabilizes the production of pure spin current. These fixed points can be of direct experimental relevance for spintronics application of normal-metalsuperconductornormal-metal junctions of one-dimensional quantum wires. We also calculate the power law temperature dependence of the crossed Andreev reflection enhanced tunnelling magnetoresistance ratio for the normal-metalsuperconductornormal-metal junction.