Estimation of electron temperature dynamics in warm dense gold using measured and DFT-calculated plasma frequency

Abstract

In this study, we report the temperature evolution of electron density of states (DOS) along with the thermophysical and optical properties of gold calculated by means of density functional theory (DFT). To corroborate the effects due to temperature-dependent electron density of states, we performed ellipsometric pump-probe experiments with broadband white-light continuum probe pulse that covered both the intraband and the interband region of the dielectric permittivity of gold. The intraband part was analyzed to give plasma frequency and collision rate as a function of the pump-probe delay. The electron temperature evolution of warm dense gold is determined by comparing the experimental plasma frequency dynamics with the DFT-calculations. The study also emphasizes the essential role of temperature-dependent modifications to the electron DOS and the thermophysical properties in order to model the non-equilibrium states of matter.