Weak phonon-mediated pairing in BiS2 superconductor from first principles
Physical Review B - Condensed Matter and Materials Physics
American Physical Society
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Morice, C., Akashi, R., Koretsune, T., Saxena, S., & Arita, R. (2017). Weak phonon-mediated pairing in BiS2 superconductor from first principles. Physical Review B - Condensed Matter and Materials Physics, 95 (18)https://doi.org/10.1103/PhysRevB.95.180505
Superconductivity in novel bismuth-sulfur 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 LaO0.5F0.5BiS2. 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 states calculations. We finally conclude that conventional phonon-mediated pairing cannot explain the high superconducting transition temperatures observed in this material.
We acknowledge support from EPSRC, Corpus Christi College, and JST, PRESTO and JSPS KAKENHI grants number JP15H03696, JP16H00924, JP16H06345 and JP15K20940. This work was supported by MEXT Element Strategy Initiative to Form Core Research Center in Japan.
External DOI: https://doi.org/10.1103/PhysRevB.95.180505
This record's URL: https://www.repository.cam.ac.uk/handle/1810/266886