Electron-lattice interactions in real materials: Bridging many-body theory and first-principles calculations
ABSTRACT
Atoms in solids constantly vibrate around their equilibrium positions. These lattice vibrations, called phonons, interact strongly with electrons and influence many material properties, from electrical resistivity to optical absorption. Developing a quantitative and predictive understanding of electron-lattice interactions remains a central challenge in computational materials science. In this talk, I will discuss my research on this problem, where I develop new theoretical concepts and computational methods by combining quantum many-body theory and first-principles electronic-structure calculations. First, I will present a many-body framework for electron transport in real materials that unifies the thermal and dynamical effects of lattice vibrations. This approach resolved a discrepancy between theory and experiment for the electrical conductivity of zinc oxide [1,2]. Next, I will introduce a new formalism I developed for a spatially localized description of phonon-mediated virtual transitions through delocalized states. This method enabled the first genuinely predictive calculation of phonon-assisted infrared absorption in silicon, in close agreement with experiments [3]. I will conclude by describing open frontiers at the intersection of electron-lattice interactions with strong electronic correlations, structural complexity, and other coupled degrees of freedom.
[1] Jae-Mo Lihm and S. Poncé, Physical Review X, 16, 011008 (2026)
[2] Jae-Mo Lihm and S. Poncé, Physical Review Letters, 134, 186401 (2025)
[3] Jae-Mo Lihm and C.-H. Park, Physical Review X, 11, 041053 (2021)
