Pressure-induced reemergence of superconductivity in topological insulator Sr0.065Bi2Se3

The recently discovered SrxBi2Se3 superconductor provides an alternative and ideal material base for investigating possible topological superconductivity. Here, we report that in Sr0.065Bi2Se3, the ambient superconducting phase is gradually depressed upon the application of external pressure. At high pressure, a second superconducting phase emerges at above 6 GPa, with a maximum T-c value of similar to 8.3 K. The joint investigations of the high-pressure synchrotron x-ray diffraction and electrical transport properties reveal that the reemergence of superconductivity in Sr0.065Bi2Se3 is closely related to the structural phase transition from an ambient rhombohedral phase to a high-pressure monoclinic phase around 6 GPa, and further to another high-pressure tetragonal phase above 25 GPa.