Gyrotropic Zener tunneling and nonlinear IV curves in the zero-energy Landau level of graphene in a strong magnetic field

TL;DR

This study explores the nonlinear tunneling behavior in graphene's zero-energy Landau level under strong magnetic fields, revealing that gyrotropic Zener tunneling dominates and influences the current-voltage characteristics.

Contribution

It introduces a model for gyrotropic Zener tunneling in graphene, highlighting the role of Lorentz force in the dielectric breakdown at the Dirac point.

Findings

Exponential current growth at breakdown onset

Zener tunneling dominates over thermal activation

Gyrotropic force significantly affects tunneling behavior

Abstract

We have investigated tunneling current through a suspended graphene Corbino disk in high magnetic fields at the Dirac point, i.e. at filling factor $\nu$ = 0. At the onset of the dielectric breakdown the current through the disk grows exponentially before ohmic behaviour, but in a manner distinct from thermal activation. We find that Zener tunneling between Landau sublevels dominates, facilitated by tilting of the source-drain bias potential. According to our analytic modelling, the Zener tunneling is strongly affected by the gyrotropic force (Lorentz force) due to the high magnetic field