title: Topological Superconductivity in Cu(x)Bi(2)Se(3).
abstract: A topological superconductor (TSC) is characterized by the topologically protected gapless surface state that is essentially an Andreev bound state consisting of Majorana fermions. While a TSC has not yet been discovered, the doped topological insulator Cu(x)Bi(2)Se(3), which superconducts below ∼3 K, has been predicted to possess a topological superconducting state. We report that the point-contact spectra on the cleaved surface of superconducting Cu(x)Bi(2)Se(3) present a zero-bias conductance peak (ZBCP) which signifies unconventional superconductivity. Theoretical considerations of all possible superconducting states help us conclude that this ZBCP is due to Majorana fermions and gives evidence for a topological superconductivity in Cu(x)Bi(2)Se(3). In addition, we found an unusual pseudogap that develops below ∼20 K and coexists with the topological superconducting state.
authors.affiliation: Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: M
authors.initials: M
authors.lastname: Kriener
authors.forename: Kouji
authors.initials: K
authors.lastname: Segawa
authors.forename: Keiji
authors.initials: K
authors.lastname: Yada
authors.forename: Yukio
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Sato
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ando