Weak Localization and Antilocalization in the Two-Dimensional Electron System on p-Type InAs

Abstract

We have performed low temperature magnetoresistance measurements of the two-dimensional electron system (2DES) in an inversion layer on p-type InAs. In high magnetic fields perpendicular to the 2DES beating patterns in Shubnikov-de Haas oscillations are observed from which the Rashba spin-orbit interaction parameter is determined. In the low-field regime we perceive weak localization and antilocalization. By fitting to the gathered localization data the elastic, inelastic, and spin relaxation times as well as coherence lengths for diffusive transport are determined for different applied gate-voltages. The Rashba parameter determined from these relaxation times is compared to the values obtained from the high-field Shubnikov-de Haas oscillations.

Spin dynamics in semiconductors

“…Experimental methods to determine the spin-orbit coupling coefficients consist of magnetotransport (including both the Shubnikov-de Haas oscillation [158][159][160][161][162][163][164][165][166][167][168] and weak (anti-)localization [137,[169][170][171][172][173][174][175][176]), optically probed spin dynamics (spin relaxation [177][178][179] and spin precession [60]), electron spin resonance [180] and spin-flip Raman scattering [133,181], etc. Recently, it was proposed that the radiation-induced oscillatory magnetoresistance can be used as a sensitive probe of the zero-field spin-splitting [182].…”

Semiclassical theory of weak antilocalization and spin relaxation in ballistic quantum dots

“…The interplay between spin dynamics and confinement effects is particularly intriguing in quantum transport through low-dimensional devices at low temperatures where quantum coherence effects additionally arise. There exist two prominent experimental probes for SO effects in quantum transport: (i) characteristic beating patterns in Shubnikov-de Haas oscillations in twodimensional electron gases with tunable SO coupling, controlled via a back-gate voltage 20,21,22,23 , and (ii) weak antilocalization 24,25,26 (WA), an enhancement of the magnetoconductance at zero magnetic field owing to spin-dependent quantum interference effects. Since systems without SO coupling exhibit weak localization (WL), i.e., a reduction in the magnetoconductance, the appearance of WA allows conclusions to be drawn on the SO strength.…”

Transition between Electron Localization and Antilocalization in Graphene

“…Until now there has been one known case where the quantum correction to the conductance is positive and accompanied by a negative MC. Such anti-localisation of electrons occurs in materials with strong spin-orbit scattering [2,3,4] where scattered electrons flip their spins and the two waves interfere destructively.In graphene electrons are very different from those in conventional two-dimensional (2D) systems. Importantly for interference, they are chiral.…”