Non-linear electric transport in graphene: quantum quench dynamics and the Schwinger mechanism

TL;DR

This paper investigates non-linear electric transport in graphene under finite electric fields, revealing a non-linear E^{3/2} current increase and connecting it to quantum quench dynamics, Schwinger pair production, and Landau-Zener tunneling.

Contribution

It provides a unified theoretical framework for understanding electric transport in graphene, linking quantum quench dynamics with Schwinger mechanism and proposing experimental tests.

Findings

Current increases as E^{3/2} in strong fields

Excited states generated by Dirac point movement

Connection to Schwinger pair production and Landau-Zener tunneling

Abstract

We present a unified view of electric transport in undoped clean graphene for finite electric field. The weak field results agree with the Kubo approach. For strong electric field, the current increases non-linearly with the electric field as E^{3/2}. As the Dirac point is moved around in reciprocal space by the field, excited states are generated, in a way analogous to the generation of defects in a quench through a quantum critical point. These results are also analyzed in terms of Schwinger's pair production and Landau-Zener tunneling. An experiment for cold atoms in optical lattices is proposed to test these ideas.