Rashba effect in inversion layers onp-type InAs MOSFET’s

Abstract

For electrons in the inversion layer on bulk p-type InAs, the Rashba spin-orbit parameter is computed self-consistently as a function of areal electron density Ns. The spin splitting increases with Ns but is not a linear function of in-plane wave vector k and the corresponding Rashba parameter increases with increasing electric field but decreases very strongly with k. For the ground subband, and at the fermi level, this decrease with k combined with subband occupation yields a decreasing Rashba parameter \ensuremath{\alpha} for $\mathrm{Ns}<1.97\ifmmode\times\else\texttimes\fi{}{10}^{12}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ and a nearly constant average value of $1.46\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\mathrm{eV}\mathrm{}\mathrm{m}$ above. At the doping level considered here $(1.8\ifmmode\times\else\texttimes\fi{}{10}^{17}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}3})$ the highest achievable value of $\ensuremath{\alpha}\ensuremath{\cong}1.92\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\mathrm{eV}\mathrm{}\mathrm{m}.$ Moreover \ensuremath{\alpha} is a nonlinear function of Ns. Our results are compared to recent experimental work by Matsuyama et al. [Phys. Rev. B 61, 15 588 (2000)] and previous theoretical treatments.