Electron-Phonon Scattering in the Presence of Soft Modes and Electron Mobility in SrTiO₃ Perovskite from First Principles

2018/06/30 by Jin-Jian Zhou, Olle Hellman, Marco Bernardi · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevlett.121.226603

published as Phys. Rev. Lett. 121, 226603 (2018) · 5 pages, 3 figures. Updated to published version

arxiv created 2018/11/30 · arxiv updated 2018/12/04

Abstract

Structural phase transitions and soft phonon modes pose a longstanding challenge to computing electron-phonon (e-ph) interactions in strongly anharmonic crystals. Here we develop a first-principles approach to compute e-ph scattering and charge transport in materials with anharmonic lattice dynamics. Our approach employs renormalized phonons to compute the temperature-dependent e-ph coupling for all phonon modes, including the soft modes associated with ferroelectricity and phase transitions. We show that the electron mobility in cubic SrTiO₃ is controlled by scattering with longitudinal optical phonons at room temperature and with ferroelectric soft phonons below 200~K. Our calculations can accurately predict the temperature dependence of the electron mobility in SrTiO₃ between 150-300~K, and reveal the microscopic origin of its roughly T^-3 trend. Our approach enables first-principles calculations of e-ph interactions and charge transport in broad classes of crystals with phase transitions and strongly anharmonic phonons.

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