Unusual Transport Properties with In-plane Magnetic Field in SrxBi2Se3 Single Crystals

Abstract

Abstract A topological insulator Bi2Se3 becomes a topological superconductor by doping Cu or Sr. Due to the nematicity of these Ax Bi2Se3 (A = Cu, Sr) materials, physical quantities show two-fold rotational symmetry as a function of in-plane magnetic field angle φ despite their three-fold structural symmetry in the plane. In this study, single crystals of Sr x Bi2Se3 (0.0 ≤ x ≤ 0.17) were grown by the self-flux method. Using these crystals, extensive measurements of the magnetoresistivity as a function of φ (ρ(φ)) were performed. Angular dependence of magnetoresistance shows an unusual cos(φ) term, which can be related to the c-axis current as well as higher harmonics components. Origins of higher harmonics components of ρ(φ) are discussed.