Superconductivity in the topological insulatorBi2Te3under hydrostatic pressure

We report the resistivity and ac susceptibility measurements of the topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ single crystals at pressures up to 11 GPa. Under highly hydrostatic pressure conditions generated in a multi-anvil high-pressure apparatus, a pressure-induced superconductivity only appears above a critical pressure ${P}_{\mathrm{C}}\ensuremath{\sim}7 \mathrm{GPa}$, coinciding with a structural transition from a rhombohedral to a monoclinic structure. The absence of superconductivity in the rhombohedral phase at pressures below ${P}_{\mathrm{C}}$, which is contrary to previous studies using the high-pressure apparatus with a solid pressure medium, suggests that the occurrence of superconductivity in the rhombohedral phase is sensitive to pressure conditions such as pressure inhomogeneity or uniaxial stress.