Nonlinear Transport of Graphene in the Quantum Hall Regime

TL;DR

This study investigates the nonlinear transport behavior and breakdown mechanisms of the integer quantum Hall effect in high-mobility graphene, revealing insights into the stability of symmetry-broken states and potential applications in quantum resistance standards.

Contribution

It provides the first comprehensive analysis of the stability of fully symmetry-broken quantum Hall states in graphene using nonlinear transport measurements.

Findings

Identified the breakdown mechanisms of QH states in graphene.

Showed the evolution of Fermi energy with Hall electric field.

Suggested v=6 states as promising for quantum resistance standards.

Abstract

We have studied the breakdown of the integer quantum Hall (QH) effect with fully broken symmetry, in an ultra-high mobility graphene device sandwiched between two single crystal hexagonal boron nitride substrates. The evolution and stabilities of the QH states are studied quantitatively through the nonlinear transport with dc Hall voltage bias. The mechanism of the QH breakdown in graphene and the movement of the Fermi energy with the electrical Hall field are discussed. This is the first study in which the stabilities of fully symmetry broken QH states are probed all together. Our results raise the possibility that the v=6 states might be a better target for the quantum resistance standard.