Spin-orbit splitting and weak antilocalization in an asymmetric /InP quantum well

Low-magnetic-field magnetoresistance of a two-dimensional electron gas (2DEG) in a triangular quantum well at a single In As-InP heterointerface has been studied. It was shown that the spin-orbit relaxation plays a significant role in the low-field magnetoresistivity in a wide range of 2DEG densities (1.8- cm . Analysis shows that both cubic and linear terms in the wavevector must be taken into account in spin splitting to describe experimental results. The linear term is mainly related to the asymmetry of the quantum well (Rashba term). Analysis of the density dependence of the spin-orbit interaction rate permits separation of the spin splittings related to the lack of inversion of the crystal and to the asymmetry of quantum well and determination of the spin splitting parameters for 2D electrons in asymmetric In As quantum wells.