title: Bulk superconducting phase with a full energy gap in the doped topological insulator Cu(x)Bi₂Se₃.
abstract: The superconductivity recently found in the doped topological insulator Cu(x)Bi₂Se₃ offers a great opportunity to search for a topological superconductor. We have successfully prepared a single-crystal sample with a large shielding fraction and measured the specific-heat anomaly associated with the superconductivity. The temperature dependence of the specific heat suggests a fully gapped, strong-coupling superconducting state, but the BCS theory is not in full agreement with the data, which hints at a possible unconventional pairing in Cu(x)Bi₂Se₃. Also, the evaluated effective mass of 2.6m(e) (m(e) is the free electron mass) points to a large mass enhancement in this material.
authors.affiliation: Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kriener
authors.forename: Kouji
authors.initials: K
authors.lastname: Segawa
authors.forename: Zhi
authors.initials: Z
authors.lastname: Ren
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ando