title: Topological surface states in lead-based ternary telluride Pb(Bi(1-x)Sb(x))2Te4.
abstract: We have performed angle-resolved photoemission spectroscopy on Pb(Bi(1-x)Sb(x))2Te4, which is a member of lead-based ternary tellurides and has been theoretically proposed as a candidate for a new class of three-dimensional topological insulators. In PbBi2Te4, we found a topological surface state with a hexagonally deformed Dirac-cone band dispersion, indicating that this material is a strong topological insulator with a single topological surface state at the Brillouin-zone center. Partial replacement of Bi with Sb causes a marked change in the Dirac carrier concentration, leading to the sign change of Dirac carriers from n type to p type. The Pb(Bi(1-x)Sb(x))2Te4 system with tunable Dirac carriers thus provides a new platform for investigating exotic topological phenomena.
authors.affiliation: WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Souma
authors.forename: K
authors.initials: K
authors.lastname: Eto
authors.forename: M
authors.initials: M
authors.lastname: Nomura
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: Kouji
authors.initials: K
authors.lastname: Segawa
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ando