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)

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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