Chiral edge mode for single-cone Dirac fermions

Abstract

We study the appearance of a chiral edge mode on the two-dimensional (2D) surface of a 3D topological insulator (TI). The edge mode appears along the 1D boundary with a magnetic insulator (MI), dependent on the angle $\theta$ which the magnetization $M$ makes with the normal to surface and on the chemical potential mismatch $\delta \mu$ across the TI--MI interface (assuming $1>\delta \mu /M\equiv \sin \varphi )$. The propagation along the interface is chiral, with velocity $v\cos (\theta -\varphi )$ smaller than the Dirac fermion velocity $v$. In momentum space the edge mode is an arc state, extending over the finite momentum interval that connects the Dirac point of the gapless Dirac fermions with the magnetic band gap. An electric field parallel to the boundary pumps charge between TI and MI via this arc state.

6 pages, 6 figures

References in corpus (6)

• Chaotic Dirac billiard in graphene quantum dots
• Topological confinement in bilayer graphene
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Zero modes and the edge states of the honeycomb lattice
• Half-Quantized Hall Effect and Power Law Decay of Edge Current Distribution
• Half-integer quantum Hall effect of disordered Dirac fermions at a topological insulator surface

Cited by in corpus (3)

• Interface-Induced Stability of Nontrivial Topological Spin Textures: Unveiling Room-Temperature Hopfions and Skyrmions
• Single-cone Dirac edge states on a lattice
• Poor-man's Majorana edge mode enabled by specular Andreev reflection