title: Pressure-induced unconventional superconducting phase in the topological insulator Bi2Se3.
abstract: Simultaneous low-temperature electrical resistivity and Hall effect measurements were performed on single-crystalline Bi2Se3 under applied pressures up to 50 GPa. As a function of pressure, superconductivity is observed to onset above 11 GPa with a transition temperature Tc and upper critical field Hc2 that both increase with pressure up to 30 GPa, where they reach maximum values of 7 K and 4 T, respectively. Upon further pressure increase, Tc remains anomalously constant up to the highest achieved pressure. Conversely, the carrier concentration increases continuously with pressure, including a tenfold increase over the pressure range where Tc remains constant. Together with a quasilinear temperature dependence of Hc2 that exceeds the orbital and Pauli limits, the anomalously stagnant pressure dependence of Tc points to an unconventional pressure-induced pairing state in Bi2Se3 that is unique among the superconducting topological insulators.
authors.affiliation: Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kirshenbaum
authors.forename: P S
authors.initials: PS
authors.lastname: Syers
authors.forename: A P
authors.initials: AP
authors.lastname: Hope
authors.forename: N P
authors.initials: NP
authors.lastname: Butch
authors.forename: J R
authors.initials: JR
authors.lastname: Jeffries
authors.forename: S T
authors.initials: ST
authors.lastname: Weir
authors.forename: J J
authors.initials: JJ
authors.lastname: Hamlin
authors.forename: M B
authors.initials: MB
authors.lastname: Maple
authors.forename: Y K
authors.initials: YK
authors.lastname: Vohra
authors.forename: J
authors.initials: J
authors.lastname: Paglione