Electron-Phonon Superconductivity in LaO$_{0.5}$F$_{0.5}$BiSe$_{2}$

Yanqing Feng; Hang-Chen Ding; Yongping Du; Xiangang Wan; Bogen Wang; Sergey Y. Savrasov; Chun-Gang Duan

doi:10.1063/1.4883755

paper

Electron-Phonon Superconductivity in LaO $_{0.5}$ F $_{0.5}$ BiSe $_{2}$

arXiv:1401.4524 · doi:10.1063/1.4883755

Abstract

We report density functional calculations of the electronic structure, Fermi surface, phonon spectrum and electron--phonon coupling for newly discovered superconductor LaO $_{0.5}$ F $_{0.5}$ BiSe $_{2}$ . Significant similarity between LaO $_{0.5}$ F $_{0.5}$ BiS $_{2}$ and LaO $_{0.5}$ F $_{0.5}$ BiSe $_{2}$ is found, i.e. there is a strong Fermi surface nesting at ( $π$ , $π$ ,0), which results in unstable phonon branches. Combining the frozen phonon total energy calculations and an anharmonic oscillator model, we find that the quantum fluctuation prevents the appearance of static long--range order. The calculation shows that LaO $_{0.5}$ F $_{0.5}$ BiSe $_{2}$ is highly anisotropic, and same as LaO $_{0.5}$ F $_{0.5}$ BiS $_{2}$ , this compound is also a conventional electron-phonon coupling induced superconductor.

5 pages, 4 figures

Electron-Phonon Superconductivity in LaO0.5​F0.5​BiSe2​

Abstract

Electron-Phonon Superconductivity in LaO $_{0.5}$ F $_{0.5}$ BiSe $_{2}$