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arXiv · 1806.05775

Electron-Phonon Scattering in the Presence of Soft Modes and Electron Mobility in SrTiO$_{3}$ Perovskite from First Principles

Jin-Jian Zhou·Olle Hellman·Marco Bernardi
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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 SrTiO$_{3}$ 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 SrTiO$_{3}$ 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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Jin-Jian Zhou, Olle Hellman, Marco Bernardi. 2018-06-15. Electron-Phonon Scattering in the Presence of Soft Modes and Electron Mobility in SrTiO$_{3}$ Perovskite from First Principles. https://doi.org/10.1103/physrevlett.121.226603

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