Strong Influence of Spin-orbit Coupling on Magnetotransport in Two-dimensional Hole Systems

Low-dimensional hole systems have attracted considerable recent attention in the context of nanoelectronics and quantum information. They exhibit strong spin-orbit coupling but a weak hyperfine interaction, which allows fast, low-power electrical spin manipulation and potentially increased coherence times while their effective spin-3/2 is responsible for physics inaccessible in electron systems. However, experimentally measuring, identifying, and quantifying spin-orbit coupling effects in transport, such as electrically-induced spin polarizations and spin Hall currents, are challenging. We show that the magnetotransport properties of two-dimensional hole systems display strong signatures of the spin-orbit interaction. Specifically, the low-magnetic field Hall coefficient and longitudinal conductivity contain a contribution that is second order in the spin-orbit interaction coefficient and is non-linear in the carrier number density. We propose an experimental setup to probe these spin-orbit dependent magnetotransport properties, which will permit one to extract the spin-orbit coefficient directly from the magnetotransport.