Edge States and Quantum Hall Effect in Graphene under a Modulated Magnetic Field

TL;DR

This paper investigates how a one-dimensional modulated magnetic field affects graphene, revealing new edge states and an unusual quantum Hall effect, with potential experimental observation and spin-related phenomena.

Contribution

It introduces a novel model of graphene under a modulated magnetic field, predicting new chiral edge states and a unique quantum Hall effect not previously described.

Findings

New chiral edge states at magnetic interface changes

Unusual integer quantum Hall effect observed

Spin-polarized edge currents with opposite propagation directions

Abstract

Graphene properties can be manipulated by a periodic potential. Based on the tight-binding model, we study graphene under a one-dimensional (1D) modulated magnetic field which contains both a uniform and a staggered component. New chiral current-carrying edge states are generated at the interfaces where the staggered component changes direction. These edge states lead to an unusual integer quantum Hall effect (QHE) in graphene, which can be observed experimentally by a standard four-terminal Hall measurement. When Zeeman spin splitting is considered, a novel state is predicted where the electron edge currents with opposite polarization propagate in the opposite directions at one sample boundary, whereas propagate in the same directions at the other sample boundary.