Observables of real-time lattice dynamics in time-dependent density functional theory

I will discuss real-time simulations of lattice vibrations in solids and their signatures in spectroscopy. In particular signatures of electron-phonon coupling in optical and electron spectroscopies have long been used to investigate materials. With the increasing interest in controlling and manipulating materials properties in a non-equilibrium state, such signatures become relevant also in pump-probe measurements. I will discuss how real-time time-dependent density functional calculations can be used to understand spectral features of electron-phonon coupling of driven electronic structure in solids [1]. A useful interpretative tool that emerges from such a treatment is the picture of a dressed electronic structure, which allows to discuss effects in driven systems without referring to perturbation theory [2].

[1] U. De Giovannini, H. Hübener, S. A. Sato and A. Rubio, PRL125, 136401 (2020)
[2] H. Hübener, U. De Giovannini, and A. Rubio, Nano Letters 18, 1535 (2018)