Abstract
We calculate the superconducting transition temperatures () in sulfur hydrides and from first principles using the density functional theory for superconductors. At pressures of GPa, the high values of ( K) observed in a recent experiment (A. P. Drozdov, M. I. Eremets, and I. A. Troyan, arXiv:1412.0460) are accurately reproduced by assuming that decomposes into and S. For higher pressures, the calculated 's for are systematically higher than those for and the experimentally observed maximum value (190 K), which suggests the possibility of another higher- phase. We also quantify the isotope effect from first principles and demonstrate that the isotope effect coefficient can be larger than the conventional value (0.5) when multiple structural phases energetically compete.
- Received 3 February 2015
- Revised 9 June 2015
DOI:https://doi.org/10.1103/PhysRevB.91.224513
©2015 American Physical Society