Mechanism of Superconductivity in Boron-Doped Diamond

ORAL

Abstract

The recent discovery of superconductivity in boron-doped diamond above liquid helium temperature has attracted considerable interest. Theoretical investigations indicate that the superconducting pairing in this material is of the conventional phonon-mediated type. However, the nature of the phonon mechanism involved and the role of the dopants are still controversial issues. In order to elucidate such issues we performed first-principles calculations of the electron-phonon interaction in boron-doped diamond, considering a virtual crystal model and a supercell model which explicitly includes the boron atoms. For each model we calculated the Eliashberg functions with high accuracy by sampling the corresponding Brillouin zone with a million of inequivalent $k$-points. We found that the localized vibrational modes associated with the boron atoms provide a significant contribution to the electron-phonon coupling strength and that superconductivity in diamond is crucially linked to the breaking of the lattice periodicity induced by the doping.

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Authors

  • Feliciano Giustino

    UC Berkeley, Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Jonathan R. Yates

    Cambridge University, United Kingdom, University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Ivo Souza

    LBNL and University of California, Berkeley, University of California, Berkeley, UC Berkeley, University of California at Berkeley and Lawrence Berkeley National Laboratory, University of California and LBNL, Berkeley

  • Marvin Cohen

    Dept of Physics UC Berkeley, Mat Sci Div LBNL, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, UC Berkeley, Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, UC Berkeley \& LBNL, UC Berkeley and Lawrence Berkeley National Laboratory

  • Steven Louie

    Molecular Foundry, Lawrence Berkeley National Laboratory and Department of Physics, University of California at Berkeley, Dept of Physics UC Berkeley, The Molecular Foundry LBNL, Mat Sci Div LBNL, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, UC Berkeley, Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, University of California at Berkeley, University of California, Berkeley \& Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California, Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory