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TT: Fachverband Tiefe Temperaturen

TT 28: Poster Session: Topological Topics

TT 28.8: Poster

Monday, March 12, 2018, 15:00–19:00, Poster B

In-plane H_c2 anisotropy of Cu_1.5(PbSe)₅(Bi₂Se₃)₆ — •Lionel Andersen, Zhiwei Wang, Thomas Lorenz, and Yoichi Ando — II. Physikalisches Institut - Universität zu Köln, Germany

The material series (PbSe)_5n(Bi₂Se₃)_3m can be understood as a natural layered heterostructure. Since the end-member PbSe is topologically trivial and the other end-member Bi₂Se₃ is a well-known topological insulator, the series provides an interesting playground for the study of topological phenomena [1]. The member of this series with n = 1 and m = 2 shows strong evidence for unconventional superconductivity after Cu doping [2]. Recently the related material Cu_xBi₂Se₃ was proved to be a topological superconductor through the observations of a spontaneous rotational symmetry breaking [3,4]. In this contribution we present a study of the H_c2 anisotropy observed in Cu_1.5(PbSe)₅(Bi₂Se₃)₆ obtained by resistance measurements. In addition to an out-of-plane anisotropy a clear in-plane anisotropy was found, which is difficult to be explained by a crystallographic or the associated Fermi surface anisotropy. This suggests a symmetry breaking similar to the case of Cu_xBi₂Se₃.
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