Chiral edge mode for single-cone Dirac fermions

Physical review. B./Physical review. B, vol. 110

Abstract

Confinement of 2D massless Dirac fermions by a mass boundary does not produce an edge mode. This applies to the surface of a 3D topological insulator at an interface to a magnetic insulator with a perpendicular magnetization. Surprisingly enough, an edge mode does appear if the magnetization is tilted away from the normal. The edge mode is an ``arc state'', ranging over a finite momentum interval, as a 2D analogue of the surface Fermi arc familiar from 3D Weyl semimetals.

Authors 1

1. C. W. J. Beenakker corresponding Aachen Instituut-Lorentz

   Leiden University

   Affiliation as printed

   Universiteit Leiden

   Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands