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arXiv · 1701.02909

Weak phonon-mediated pairing in BiS$_2$ superconductor from first principles

Corentin Morice·Ryosuke Akashi·Takashi Koretsune·Siddharth S. Saxena·Ryotaro Arita
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Abstract

Superconductivity in novel bismuth-sulphur superconductors has attracted large research efforts, both experimental and theoretical, but a consensus on the nature of superconductivity in these materials has yet to be reached. Using density functional theory for superconductors, we study the electron-phonon pairing mechanism in LaO$_{0.5}$F$_{0.5}$BiS$_2$. We first confirm the presence of a commensurate charge density wave instability, in accordance with previous studies. Using a recently developed integration scheme for the electron-phonon coupling, we found that its strength is much lower than previously calculated, due to improved density of state calculations. We finally conclude that conventional phonon-mediated pairing cannot explain the high superconducting transition temperatures observed in this material.

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Corentin Morice, Ryosuke Akashi, Takashi Koretsune, Siddharth S. Saxena, Ryotaro Arita. 2017-01-11. Weak phonon-mediated pairing in BiS$_2$ superconductor from first principles. https://doi.org/10.1103/physrevb.95.180505

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