Band structure and magnetotransport of a two-dimensional electron gas in the presence of spin-orbit interaction

摘要

The band structure and magnetotransport of a two-dimensional electron gas (2DEG), in the presence of the Rashba (RSOI) and Dresselhaus (DSOI) terms of the spin-orbit interaction and of a perpendicular magnetic field, is investigated. Exact and approximate analytical expressions for the band structure are obtained quantum mechanically and used to calculate the density of states (DOS) and the longitudinal magnetoresitivity assuming a Gaussian type of level broadening. The interplay between the Zeeman coupling and the two terms of the SOI is discussed. If the strengths α and β, of the RSOI and DSOI, respectively, are equal and the g factor vanishes, the two spin states are degenerate and a shifted Landau-level structure appears in agreement with recent semiclassical results. With the increase of the difference α-β, a beating pattern of the DOS and of the Shubnikov-de Haas oscillations appears distinctly different from that occurring when one of these strengths vanishes. For α β or α β the peaks in one wrap of the beating pattern occur at even filling factors of the 2DEG while in the next wrap they occur at odd filling factors. For α≈β this transition occurs only if the spin splitting is larger than half the Landau energy.