498 / 2019-03-18 22:49:33

Pressure-induced Lifshitz transitions and superconductivity in NbxBi2Se3

electronic topological transition,superconductivity,topological insulator

全体主题 > High Pressure Physics and Materials Science

The tunability of electronic topological transition (ETT) is of fundamental interest to unveil new quantum matters. However, whether the pressure induced ETT exists in Bi2Se3-based topological materials is still unclarified. Here, combined with electrical transport, synchrotron x-ray diffraction, Raman scattering spectroscopy and first principle calculations, we unambiguously observed three ETTs below 12.0 GPa in Nb0.25Bi2Se3. The rare multiple ETTs can be understood by pressure-induced Fermi surface reconstructions of three distinct bands at time reversal invariant points. We further presented first evidence of multiband superconductivity characterized by an upward curvature in upper critical field in pressurized Nb0.25Bi2Se3 crystal. These new findings highlight the critical role of multiple band structure induced by strong hybridization between Nb-4d and Bi/Se-p orbitals in accessing novel quantum states.