title: Charge and spin transport in edge channels of a ν=0 quantum Hall system on the surface of topological insulators.
abstract: Three-dimensional topological insulators of finite thickness can show the quantum Hall effect (QHE) at the filling factor ν=0 under an external magnetic field if there is a finite potential difference between the top and bottom surfaces. We calculate energy spectra of surface Weyl fermions in the ν=0 QHE and find that gapped edge states with helical spin structure are formed from Weyl fermions on the side surfaces under certain conditions. These edge channels account for the nonlocal charge transport in the ν=0 QHE which is observed in a recent experiment on (Bi_{1-x}Sb_{x})_{2}Te_{3} films. The edge channels also support spin transport due to the spin-momentum locking. We propose an experimental setup to observe various spintronics functions such as spin transport and spin conversion.
authors.affiliation: Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Morimoto
authors.affiliation: Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.|RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Furusaki
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.|Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Nagaosa