Dirac fermion wave guide networks on topological insulator surfaces

TL;DR

This paper demonstrates how magnetic texturing on topological insulators can create wave guide networks for Dirac fermions, enabling tunable interference effects and proposing a Dirac fermion transistor based on these principles.

Contribution

It introduces a novel modeling approach for Dirac fermion interferometers on topological insulators using a new discretization scheme and explores their potential for electronic device applications.

Findings

Transmission can be tuned via magnetization or bias.

A Dirac fermion transistor concept is proposed.

Extensions to complex networks are discussed.

Abstract

Magnetic texturing on the surface of a topological insulator allows the design of wave guide networks and beam splitters for domain-wall Dirac fermions. Guided by simple analytic arguments we model a Dirac fermion interferometer consisting of two parallel pathways, whereby a newly developed staggered-grid leap-frog discretization scheme in 2+1 dimensions with absorbing boundary conditions is employed. The net transmission can be tuned between constructive to destructive interference, either by variation of the magnetization (path length) or an applied bias (wave length). Based on this principle, a Dirac fermion transistor is proposed. Extensions to more general networks are discussed.