Surface-edge state and half quantized Hall conductance in topological insulators

TL;DR

This paper introduces a surface-edge state theory explaining the half quantized Hall conductance in topological insulators, highlighting a new chiral edge state on the surface edges caused by magnetic field effects.

Contribution

It presents a novel surface-edge state model for half quantized Hall conductance, including the physical interpretation of the conductance as a boundary state splitting.

Findings

Demonstrates gap opening of a Dirac cone in weak magnetic fields.

Identifies a new surface state on edges carrying chiral current.

Provides a physical interpretation linking boundary states to conductance quantum.

Abstract

We propose a surface-edge state theory for half quantized Hall conductance of surface states in topological insulators. The gap opening of a single Dirac cone for the surface states in a weak magnetic field is demonstrated. We find a new surface state resides on the surface edges and carries chiral edge current, resulting in a half-quantized Hall conductance in a four-terminal setup. We also give a physical interpretation of the half quantized conductance by showing that this state is the product of splitting of a boundary bound state of massive Dirac fermions which carries a conductance quantum.