Gap opening in the zeroth Landau level in gapped graphene: Pseudo-Zeeman splitting in an angular magnetic field

TL;DR

This paper theoretically investigates how pseudo-Zeeman interaction causes gap opening in the zeroth Landau level of gapped graphene, affecting quantum Hall transport properties under an angular magnetic field.

Contribution

It introduces a theoretical model for pseudo-Zeeman splitting effects on quantum Hall conductivities in gapped graphene with an angular magnetic field.

Findings

Pseudo-Zeeman splitting causes a minimum in collisional conductivity at high magnetic fields.

A zero plateau appears in the Hall conductivity due to pseudo-Zeeman effects.

Activated transport behavior is observed at the Charge Neutrality Point.

Abstract

We present a theoretical study of gap opening in the zeroth Landau level in gapped graphene as a result of pseudo-Zeeman interaction. The applied magnetic field couples with the valley pseudospin degree of freedom of the charge carriers leading to the pseudo-Zeeman interaction. To investigate its role in transport at the Charge Neutrality Point (CNP), we study the integer quantum Hall effect (QHE) in gapped graphene in an angular magnetic field in the presence of pseudo-Zeeman interaction. Analytical expressions are derived for the Hall conductivity using Kubo-Greenwood formula. We also determine the longitudinal conductivity for elastic impurity scattering in the first Born approximation. We show that pseudo-Zeeman splitting leads to a minimum in the collisional conductivity at high magnetic fields and a zero plateau in the Hall conductivity. Evidence for activated transport at CNP is found from the temperature dependence of the collisional conductivity.