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

TL;DR

This paper investigates the band structure and magnetotransport properties of a two-dimensional electron gas influenced by spin-orbit interactions and magnetic fields, revealing novel beating patterns in the density of states and oscillations.

Contribution

It provides exact and approximate analytical expressions for the band structure considering Rashba and Dresselhaus spin-orbit interactions and explores their effects on magnetotransport phenomena.

Findings

Degenerate spin states when RSOI and DSOI are equal and g-factor is zero.

Emergence of a beating pattern in DOS and SdH oscillations with increasing difference between RSOI and DSOI.

Distinct Landau-level structures depending on the relative strengths of spin-orbit interactions.

Abstract

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 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 $\alpha$ and $ \beta$, 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. With the increase of the difference $\alpha- \beta$, a novel beating pattern of the DOS and of the Shubnikov-de Haas (SdH) oscillations appears distinctly different from that occurring when one of these strengths vanishes.