Superconducting and normal-state anisotropy of the doped topological insulator Sr0.1Bi2Se3

• Published in: Scientific reports 2018-05, Vol.8 (1), p.1-10, Article 7666
• Main Authors: Smylie, M. P., Willa, K., Claus, H., Koshelev, A. E., Song, K. W., Kwok, W.-K., Islam, Z., Gu, G. D., Schneeloch, J. A., Zhong, R. D., Welp, U.
• Format: Article
• Language: English
• Subjects: 639/766/119/1003; 639/766/119/2792; 639/766/119/995; 639/766/119/997; Anisotropy; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electronic properties and materials; Humanities and Social Sciences; Magnetic properties; Magnetic properties and materials; MATERIALS SCIENCE; multidisciplinary; Science; Science (multidisciplinary); Superconducting properties and materials; Topological matter; X-ray diffraction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-26032-0

Sr x Bi 2 Se 3 and the related compounds Cu x Bi 2 Se 3 and Nb x Bi 2 Se 3 have attracted considerable interest, as these materials may be realizations of unconventional topological superconductors. Superconductivity with T c  ~3 K in Sr x Bi 2 Se 3 arises upon intercalation of Sr into the layered topological insulator Bi 2 Se 3 . Here we elucidate the anisotropy of the normal and superconducting state of Sr 0.1 Bi 2 Se 3 with angular dependent magnetotransport and thermodynamic measurements. High resolution x-ray diffraction studies underline the high crystalline quality of the samples. We demonstrate that the normal state electronic and magnetic properties of Sr 0.1 Bi 2 Se 3 are isotropic in the basal plane while we observe a large two-fold in-plane anisotropy of the upper critical field in the superconducting state. Our results support the recently proposed odd-parity nematic state characterized by a nodal gap of Eu symmetry in Sr x Bi 2 Se 3 .