Volume 81, Number 6, March 2008
Article Number 67001
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 27 February 2008
EPL, 81 (2008) 67001
DOI: 10.1209/0295-5075/81/67001

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

Sourin Das1, Sumathi Rao2 and Arijit Saha2

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 in final form 30 January 2008; published March 2008
published online 27 February 2008

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-metal$\hbox{--} $superconductor$\hbox{--} $normal-metal, where, the normal metal is a one-dimensional interacting quantum wire. We show that there are fixed points in the theory which correspond to the case of pure spin current. We analyze the influence of electron-electron interaction and see how it stabilizes or de-stabilizes the production of pure spin current. These fixed points can be of direct experimental relevance for spintronics application of normal-metal$\hbox{--} $superconductor$\hbox{--} $normal-metal junctions of one-dimensional quantum wires. We also calculate the power law temperature dependence of the crossed Andreev reflection enhanced tunnelling magnetoresistance ratio for the normal-metal$\hbox{--} $superconductor$\hbox{--} $normal-metal junction.

73.23.-b - Electronic transport in mesoscopic systems.
74.45.+c - Proximity effects; Andreev effect; SN and SNS junctions.
72.25.Ba - Spin polarized transport in metals.

© EPLA 2008