Dependence of quantum-Hall conductance on the edge-state equilibration position in a bipolar graphene sheet

TL;DR

This study explores how the position of edge-state equilibration affects quantum-Hall conductance in a bipolar graphene sheet, revealing asymmetries linked to chiral edge-state behavior.

Contribution

It provides new insights into the dependence of quantum-Hall edge-state equilibration on device configuration and chiral direction in graphene p-n interfaces.

Findings

Resistance asymmetry related to zero filling factor point

Chiral-direction-dependent change in equilibration position

Deeper understanding of edge-state equilibration process

Abstract

By using four-terminal configurations, we investigated the dependence of longitudinal and diagonal resistances of a graphene p-n interface on the quantum-Hall edge-state equilibration position. The resistance of a p-n device in our four-terminal scheme is asymmetric with respect to the zero point where the filling factor ($\nu$) of the entire graphene vanishes. This resistance asymmetry is caused by the chiral-direction-dependent change of the equilibration position and leads to a deeper insight into the equilibration process of the quantum-Hall edge states in a bipolar graphene system.