Many-body perturbation theory approach to the electron-phonon interaction with density-functional theory as a starting point
(2015) Physical review. B, Condensed matter and materials physics — Vol. 91, n° 22, p. 224310 (2015)
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- Abstract
- The electron–phonon interaction plays a crucial role in many fields of physics and chemistry. Nevertheless, its actual calculation by means of modern many–body perturbation theory is weakened by the use of model Hamiltonians that are based on parameters difficult to extract from the experiments. Such shortcoming can be bypassed by using density–functional theory to evaluate the electron–phonon scattering amplitudes, phonon frequencies and electronic bare energies. In this work, we discuss how a consistent many–body diagrammatic expansion can be constructed on top of density–functional theory. In that context, the role played by screening and self–consistency when all the components of the electron–nucleus and nucleus–nucleus interactions are taken into account is paramount. A way to avoid overscreening is notably presented. Finally, we derive cancellations rules as well as internal consistency constraints in order to draw a clear, sound and practical scheme to merge many–body perturbation and density–functional theory.
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Citations
Marini, A., Poncé, S., & Gonze, X. (2015). Many-body perturbation theory approach to the electron-phonon interaction with density-functional theory as a starting point. Physical review. B, Condensed matter and materials physics, 91(22), 224310. https://doi.org/10.1103/PhysRevB.91.224310 (Original work published 2015)