Possibility for conventional superconductivity in Sr0.1Bi2Se3 from high-pressure transport studies

Abstract

SrxBi2Se3 is recently reported to be a superconductor derived from topological insulator Bi2Se3. It shows a maximum resistive Tc of 3.25 K at ambient pressure. We report magnetic (up to 1 GPa) and transport properties (up to 8 Gpa) under pressure for single crystalline Sr0.1Bi2Se3 superconductor. Magnetic measurements show that Tc decreases from ∼2.6 K (0 GPa) to ∼1.9 K (0.81 GPa). Similar behavior is observed in transport properties as well without much change in the metallic characteristics in normal-state resistivity. No reentrant superconducting phase (Zhou Y. et al., Phys. Rev. B, 93 (2016) 144514) is observed at high pressure. Normal-state resistivity near Tc is explained by Fermi liquid model. Band structure calculations indicate decreasing density of states at Fermi level with pressure. In consonance with transition temperature suppression in conventional BCS low-Tc superconductors, the pressure effect in SrxBi2Se3 is well accounted by pressure-induced band broadening.