Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 22: Poster session I

MM 22.6: Poster

Montag, 20. März 2017, 19:00–20:00, P4

Theory of Polaron Band Narrowing and Phonon Renormalization due to Quadratic Electron-Phonon Coupling — •Pablo Garcia Risueno, Qiang Fu, and Claudia Draxl — Humboldt Universität zu Berlin, Physics Department and IRIS Adlershof

We present a novel theory of electron-lattice interaction beyond the linear-coupling regime. Based on the solution of a Holstein-Peierls-type model for quadratic electron-phonon coupling, we derive explicit analytical expressions for the eigenvalue spectrum of the Hamiltonian, resulting in a narrowing of bands as a function of temperature. Being nonperturbative, our formalism also applies in the strong-coupling case. It provides a starting point for potential applications to real materials by supplementing it with ab initio parameters.