Spin Relaxation in Silicon Nanowires

TL;DR

This paper models spin transport in silicon nanowires and 2D channels, revealing longer spin relaxation lengths in nanowires and the influence of electric fields, aiding spintronics device design.

Contribution

It introduces a simulation approach combining spin density matrix and Monte Carlo methods to analyze spin relaxation in silicon nanostructures.

Findings

Spin relaxation length is an order of magnitude higher in nanowires than in 2D channels.

Electric field affects spin relaxation length.

Results are relevant for designing spintronics devices.

Abstract

We simulate spin polarized transport of electrons along a silicon nanowire and along a silicon two dimensional channel. Spin density matrix calculations are used along with the semi-classical Monte Carlo approach to model spin evolution along the channel. Spin dephasing in silicon is caused due to Rashba Spin Orbit Interaction (structural inversion asymmetry) which gives rise to D'yakonov-Perel' relaxation. Spin relaxation length in a nanowire is found to be an order of magnitude higher than that in a 2-D channel. The effect of driving electric field on spin relaxation is also investigated. These results obtained are essential for design of spintronics based devices.