Spin-Orbit Interaction in InSb Thin Films Grown on GaAs (100) Substrates by MBE: Effect of Hetero-Interface

Abstract

Magnetoresistance (MR) effects caused by quantum interference have been investigated in order to search into the spin‐orbit interaction (SOI) in the InSb films grown on GaAs(100) substrates by MBE. The positive MR in the accumulation layer at the InSb/GaAs interface arises from the two‐dimensional (2D) weak anti‐localization (WAL) and is explained by taking account of the spin‐Zeeman effect on the SOI caused by the asymmetric potential at the hetero interface (Rashba term with SO scattering rate τSO−1 ∼ 1.7 × 1012 s−1). The negative MR in extremely weak magnetic fields found for Sn‐doped films dramatically crossovers to the positive MR with decreasing the film thickness. The results have been analyzed using a two‐layer model for the films; the SO scattering rate in the intrinsic InSb film due to the bulk inversion asymmetry (Dresselhaus term) has been found to be as small as τSO−1 ⩽ 2 × 109 s−1 and when the interface is approached in the film the WL crossovers to the WAL with the increase of SOI in the la...