Gate controlled crossover from weak localization to weak antilocalization in a narrow gap In 0.8 Ga 0.2 As/InP heterostructure

Abstract

We have investigated gate voltage dependence of the Rashba spin-orbit interaction (SOI) in an In0.52Al0.48As/5nm In0.8Ga0.2As/InP narrow quantum well by using weak antilocalization analysis. As the gate voltage increases, clear crossover transition from weak localization to weak antilocalization is observed in the identical sample, which indicates that strength of the Rashba SOI systematically changes. Rashba SOI parameter α is found to increase with carrier density, which is in agreement with the calculated values from the k·p theory. By comparing the obtained Rashba parameter α with the calculated interface and field contributions, combination of In0.8Ga0.2As/InP interface and In0.8Ga0.2As field contributions determines the variation of the Rashba SOI with gate bias voltage. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)