title: Surface-dominated transport on a bulk topological insulator.
abstract: Topological insulators are guaranteed to support metallic surface states on an insulating bulk, and one should thus expect that the electronic transport in these materials is dominated by the surfaces states. Alas, due to the high remaining bulk conductivity, it is challenging to achieve surface-dominated transport. Here we use nanoscale four-point setups with a variable contact distance on an atomically clean surface of bulk-insulating Bi2Te2Se. We show that the transport at 30 K is two-dimensional rather than three-dimensional, that is, surface-dominated, and we find a surface state mobility of 390(30) cm(2) V(-1) s(-1) at 30 K at a carrier concentration of 8.71(7) × 10(12) cm(-2).
authors.affiliation: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center (iNANO), Aarhus University , 8000 Aarhus C, Denmark.
authors.forename: Lucas
authors.initials: L
authors.lastname: Barreto
authors.forename: Lisa
authors.initials: L
authors.lastname: Kühnemund
authors.forename: Frederik
authors.initials: F
authors.lastname: Edler
authors.forename: Christoph
authors.initials: C
authors.lastname: Tegenkamp
authors.forename: Jianli
authors.initials: J
authors.lastname: Mi
authors.forename: Martin
authors.initials: M
authors.lastname: Bremholm
authors.forename: Bo Brummerstedt
authors.initials: BB
authors.lastname: Iversen
authors.forename: Christian
authors.initials: C
authors.lastname: Frydendahl
authors.forename: Marco
authors.initials: M
authors.lastname: Bianchi
authors.forename: Philip
authors.initials: P
authors.lastname: Hofmann