Quantum and transport lifetimes of a two-dimensional hole gas in the presence of spin-orbit interaction

We present a simple theoretical approach for evaluating the spin-dependent carrier distribution as well as quantum and transport lifetimes in a two-dimensional hole gas (2DHG) in the presence of spin-orbit interaction (SOI) induced by the Rashba effect. For low temperatures and over a wide range of the sample parameters, the SOI can enhance the mobility of the sample system and the quantum and transport lifetimes of a 2DHG due to background-impurity scattering do not differ significantly between different spin branches. These are mainly due to the unique features of the hole-impurity scattering in the presence of the SOI. A small difference of the quantum lifetimes in different spin branches has been observed experimentally in spin-split two-dimensional electron gas systems. Our results indicate that this interesting observation can be made in spin-split 2DHGs as well. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.