Magnetotransport properties of a magnetically modulated two-dimensional electron gas with the spin-orbit interaction

TL;DR

This paper analyzes how a weak magnetic modulation affects the electrical transport in a 2D electron gas with Rashba spin-orbit interaction, revealing oscillation patterns that can determine the Rashba strength.

Contribution

It provides analytical expressions for diffusive conductivities in a modulated 2DEG with Rashba interaction, enabling determination of Rashba strength from experimental beating patterns.

Findings

Conductivities oscillate with different frequencies for spin-up and spin-down electrons.

Beating patterns in Weiss oscillations can be used to extract Rashba coupling strength.

Theoretical results agree with behavior observed in electrically modulated 2DEG systems.

Abstract

We study the electrical transport properties of a two-dimensional electron gas with the Rashba spin-orbit interaction in presence of a constant perpendicular magnetic field $(B_0 \hat z)$ which is weakly modulated by ${\bf B_1} = B_1 \cos (q x) \hat z$, where $B_1 \ll B_0 $ and $q = 2 \pi/a $ with $a$ is the modulation period. We obtain the analytical expressions of the diffusive conductivities for spin-up and spin-down electrons. The conductivities for spin-up and spin-down electrons oscillate with different frequencies and produce beating patterns in the amplitude of the Weiss and Shubnikov-de Haas oscillations. We show that the Rashba strength can be determined by analyzing the beating pattern in the Weiss oscillation. We find a simple equation which determines the Rashba spin-orbit interaction strength if the number of Weiss oscillations between any two successive nodes is known from the experiment. We compare our results with the electrically modulated 2DEG with the Rashba interaction. For completeness, we also study the beating pattern formation in the collisional and the Hall conductivities.