First-Principles Study of Superconductivity in boron-doped SiC

ORAL

Abstract

The discovery of superconductivity in materials such as intercalated graphite, alkali-doped fullerenes, and boron-doped diamond has drawn significant interest to carbon-based superconductors. Recent experiments indicate that boron-doped cubic SiC may superconduct above 1 K [1]. We investigate the superconductivity in cubic SiC using a first-principles approach. We describe the electronic structure within density functional theory and the lattice dynamics within density functional perturbation theory. The electron-phonon interaction matrix elements are calculated via a recently developed method based on Wannier functions [2]. The boron doping is accounted for by a virtual crystal approximation. In addition to the coupling of Fermi surface electronic states to optical phonon modes, there appears to be a non-negligible contribution to the electron-phonon coupling arising from acoustic phonons. Superconductivity is discussed by analyzing the similarities and the differences with respect to the closely related boron-doped diamond. [1] Z-A. Ren et. al, \textit{private communication}. [2] F. Giustino et. al, Phys. Rev. B 76, 165108 (2007)

*This work was supported by NSF Grant No. DMR07-05941, the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Computational resources have been provided by NERSC and NPACI.

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Authors

  • Jesse Noffsinger

    • UC Berkeley

  • Feliciano Giustino

    • Department of Physics, University of California at Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • UC Berkeley

  • Steven G. Louie

    • Department of Physics, UC Berkeley
    • Department of Physics, University of California at Berkeley and Materials Sciences Division of Lawrence Berkeley National Laboratory
    • UC Berkeley, and LBL
    • UC Berkeley
    • Dept. of Physics, UC Berkeley; MSD, LBNL
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Molecular Foundry, LBNL and Physics Dept, UC Berkeley
    • UC Berkeley and LBNL
    • University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Marvin L. Cohen

    • UC Berkeley, Lawrence Berkeley National Laboratory
    • Department of Physics, U C Berkeley, Material Science Divsion, LBNL
    • epartment of Physics, UC Berkeley
    • University of California, Berkeley
    • UC Berkeley, and LBL
    • UC Berkeley
    • UC Berkeley \& LBNL