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.

*This work was supported by the NSF under Grant No. DMR04-39768, and the U.S. DOE under Contract No. DE-AC02-05CH11231. Computer time was provided by NERSC and NPACI.

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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