Magneto-electronic properties of multilayer black phosphorus

TL;DR

This paper investigates the electronic and magneto-optical properties of multilayer black phosphorus under magnetic fields, revealing anisotropic effects and doping-dependent resonances due to inter-band coupling and Coulomb interactions.

Contribution

It provides a detailed analysis of how in-plane anisotropy and inter-band coupling influence magneto-electronic phenomena in multilayer black phosphorus.

Findings

Resonant ac conductivity exhibits a red-shift with increased doping.

Inter-band coupling introduces a correction term proportional to $n^2b3^2$ in Landau levels.

Coulomb interactions cause highly anisotropic magneto-excitons.

Abstract

We examine the electronic properties of 2D electron gas in black phosphorus multilayers in the presence of a perpendicular magnetic field, highlighting the role of in-plane anisotropy on various experimental quantities such as ac magneto-conductivity, screening, and magneto-plasmons. We find that resonant structures in the ac conductivity exhibits a red-shift with increasing doping due to inter-band coupling, $\gamma$. This arises from an extra correction term in the Landau energy spectrum proportional to $n^2\gamma^2$ ($n$ is Landau index), up to second order in $\gamma$. We found also that Coulomb interaction leads to highly anisotropic magneto-excitons.