Evidence for singular-phonon-induced nematic superconductivity in a topological superconductor candidate Sr_0.1Bi₂Se₃.

ABSTRACT: Superconductivity mediated by phonons is typically conventional, exhibiting a momentum-independent s-wave pairing function, due to the isotropic interactions between electrons and phonons along different crystalline directions. Here, by performing inelastic neutron scattering measurements on a superconducting single crystal of Sr_0.1Bi₂Se₃, a prime candidate for realizing topological superconductivity by doping the topological insulator Bi₂Se₃, we find that there exist highly anisotropic phonons, with the linewidths of the acoustic phonons increasing substantially at long wavelengths, but only for those along the [001] direction. This observation indicates a large and singular electron-phonon coupling at small momenta, which we propose

SUBMITTER: Wang J 

PROVIDER: S-EPMC6594966 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature