Rashba spin splitting in inversion layers onp-type bulk InAs

Abstract

The dependence of the spin-orbit interaction on electron density in inversion layers of metal-oxide-semiconductor field-effect transistors on p-type InAs is studied by magnetotransport at liquid-helium temperatures. We observe beating patterns in the Shubnikov--de Haas oscillations, which manifest the Rashba effect in a triangular surface potential. Taking subband nonparabolicity into account we evaluate Rashba parameters $\ensuremath{\alpha}$ that increase with electron density ${n}_{s}$ reaching a value $\ensuremath{\alpha}=3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\mathrm{eV}\mathrm{}\mathrm{m}$ at densities ${n}_{s}>~2.2\ifmmode\times\else\texttimes\fi{}{10}^{12}{\mathrm{cm}}^{\ensuremath{-}2}.$ Implications for the spin-dependent transport in spin-polarized high-electron-mobility transistors utilizing InAs quantum wells are discussed.