Finite transverse conductance and anisotropic magnetoconductance in spin orbit coupled two dimensional electron gas under an applied in-plane magnetic field

Abhiram Soori

Published 2021-03-10Version 1

The current in response to a bias in certain two-dimensional electron gas (2DEG), can have a nonzero transverse component under a finite magnetic field applied in the plane where electrons are confined. Typically, this is accompanied by dependencies of both the longitudinal and the transverse components of current on the angle $\phi$ between the bias direction and the magnetic field. This happens in a variety of systems, for example in topological insulators where spin-orbit coupling (SOC) is the root cause for the effect. In 2DEG with SOC such as oxide interfaces, this effect has been experimentally witnessed. Further, a fourfold oscillation in longitudinal resistance as a function of $\phi$ has also been observed. Motivated by these, we perform scattering theory calculations on a 2DEG with SOC in presence of an in-plane magnetic field connected to two dimensional leads on either sides to obtain longitudinal and transverse conductances. We find that the longitudinal conductance is $\pi$-periodic and the transverse conductance is $2\pi$-periodic in $\phi$. The magnitude of oscillation in transverse conductance with $\phi$ is enhanced in certain patches in $(\alpha,b)$-plane where $\alpha$ is the strength of SOC and $b$ is Zeeman energy due to magnetic field. The oscillation in transverse conductance with $\phi$ can be highly multi-fold for large values of $\alpha$ and $b$. The highly multi-fold oscillations of transverse conductance are due to Fabry-P\'erot type interference between the modes in the central region as backed by its length dependent features.