Effect of electric field and temperature variability on spin dephasing in SiGe nanowires

Abstract

In this paper, we use semi classical Monte Carlo method to investigate Effect of electric field and temperature variability on spin polarized transport in SiGe nanowires (SiGeNWs) with Ge mole fraction of 0.2, 0.4, 0.6 and 0.8. We use a multi-subbands semi classical Monte Carlo approach to model spin dephasing. Monte Carlo simulations have been widely adopted to study electron transport in devices and have recently been used in conjunction with spin density matrix calculations to model spin transport. Spin dephasing in SiGe nanowires (SiGeNWs) is caused due to D'yakonov-Perel (DP) relaxation and due to Elliott-Yafet (EY) relaxation. The components of ensemble averaged spin variation have been studied for SiGe nanowires (SiGeNWs) along the nanowires length. The effect of variation of electric field and temperature on spin dephasing length has been studied. It is found that variation of the electric field does not affect spin dephasing length significantly but spin dephasing length decrease as Ge mole fraction increases from 0.2 to 0.8 for the same value of electric field in SiGe nanowires (SiGeNWs). The effect of variation of temperature is more visible and as temperature increases from 10K to 300K spin dephasing length decrease due to dominant increase of acoustic phonon scattering and it decrease more dominantly for higher value of Ge mole fraction such as 0.8 compare to 0.2.