Abstract
Electron-phonon () interactions are pervasive in condensed matter, governing phenomena such as transport, superconductivity, charge-density waves, polarons, and metal-insulator transitions. First-principles approaches enable accurate calculations of interactions in a wide range of solids. However, they remain an open challenge in correlated electron systems (CES), where density functional theory often fails to describe the ground state. Therefore reliable calculations remain out of reach for many transition metal oxides, high-temperature superconductors, Mott insulators, planetary materials, and multiferroics. Here we show first-principles calculations of interactions in CES, using the framework of Hubbard-corrected density functional theory () and its linear response extension (), which can describe the electronic structure and lattice dynamics of many CES. We showcase the accuracy of this approach for a prototypical Mott system, CoO, carrying out a detailed investigation of its interactions and electron spectral functions. While standard DFPT gives unphysically divergent and short-ranged interactions, is shown to remove the divergences and properly account for the long-range Fröhlich interaction, allowing us to model polaron effects in a Mott insulator. Our work establishes a broadly applicable and affordable approach for quantitative studies of interactions in CES, a novel theoretical tool to interpret experiments in this broad class of materials.
- Received 19 February 2021
- Accepted 12 August 2021
DOI:https://doi.org/10.1103/PhysRevLett.127.126404
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