The role of the Fermi surface sampling in first-principles calculations of electron-phonon coupling

ORAL

Abstract

A quantitative understanding of the electron-phonon interaction is crucial to the understanding of conventional and possibly high-T$_{\rm c}$ superconductivity, as well as to the study of transport and spectroscopic (such as optical and photoemission) properties of bulk and nanoscale systems. Despite the enormous interest in calculating electron-phonon interaction from first principles, present methods carry severe practical limitations. We present here a comparative study of several existing methods for computing this quantity. We show that, independent of the approximation adopted, a common computational bottleneck is that the Fermi surface must be sampled with extremely high accuracy, leading to prohibitively expensive calculations for complex systems. We also reformulate the problem of evaluating phonon linewidths in terms of self-consistent linear response theory, and demonstrate our approach through application to magnesium diboride.

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Authors

  • Feliciano Giustino

    University of California at Berkeley

  • Marvin L. Cohen

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

  • Steven Louie

    Department of Physics, University of California, Berkeley \& The Molecular Foundry, Materials Sciences Division,Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, UC Berkeley and Lawrence Berkeley National Laboratory, Department of Physics, University of California at Berkeley and Materials Sciences Division, LBNL, Dept of Physics, UC Berkeley, The Molecular Foundry, LBNL, University of California at Berkeley, Department of Physics, University of California at Berkeley and Materials Sciences Divisions, LBNL