Ab initio model of optical properties of two-temperature warm dense matter

TL;DR

This paper introduces an ab initio model based on density functional theory to predict the optical and thermophysical properties of two-temperature warm dense matter during ultrafast laser heating, aligning simulations with experimental data.

Contribution

The study develops a unified ab initio framework combining density functional theory and the Kubo-Greenwood formula to model ultrafast heating effects in gold.

Findings

Model accurately predicts optical properties during femtosecond laser heating.

Simulation results agree with recent time-resolved experimental measurements.

Provides insights into temperature relaxation dynamics in warm dense gold.

Abstract

We present a model to describe thermophysical and optical properties of two-temperature systems consisted of heated electrons and cold ions in a solid lattice that occur during ultrafast heating experiments. Our model is based on ab initio simulations within the framework of density functional theory. The optical properties are obtained by evaluating the Kubo-Greenwood formula. By applying the material parameters of our ab initio model to a two-temperature model we are able to describe the temperature relaxation process of femtosecond-laser-heated gold and its optical properties within the same theoretical framework. Recent time-resolved measurements of optical properties of ultrafast heated gold revealed the dynamics of the interaction between femtosecond laser pulses and solid state matter. Different scenarios obtained from simulations of our study are compared with experimental data [Chen, Holst, Kirkwood, Sametoglu, Reid, Tsui, Recoules, and Ng, Phys. Rev. Lett. 110, 135001 (2013)].