Ab initio study of polaron dynamics in metal oxides

Abstract

Among the family of quasiparticles in condensed matters, polaron, that is bound state of electron and phonons, is involved in various physics in metal oxide, such as the life time of excited state, carrier conductivity, and electron-electron pairing in the strong coupling regime. Whereas polaron-related phenomena have been mostly studied with model Hamiltonian, here we use real-time evolution of time-dependent density functional theory plus Hubbard U to calculate them within the gear of ab initio. As a case study, we calculated the excitation of STO, and we found that some particular charge-ordered excitation can result in a resonant mode of oscillation. We also calculated the polaron transport in STO/LAO interface, and found that the interchange between polaronic state and the conduction band state can lead to a long range fast teleportation of Holstein-type polaron.