Study of Non-Equilibrium Dynamics in Warm Dense Matter under Femtosecond Laser Excitation Gwangju Institute of Science and Technology Hyeonjin Lee

Abstract

This thesis presents the theoretical approaches to model the non-thermal electron dynamics which can be provide the insights of the materials and describe the abnormal physical behavior in warm dense matter states, which at extreme condition of high energy-density. Combined with density functional theory, the dynamic d-band characterization was visualized and the optical response of WD-Au simulation achieved self-consistency. The non-thermal effects were introduced with modified two temperature model (m-TTM). Experimentally, the optical measurements using 800 nm femtosecond lasers are conducted. To evaluate the non-thermal effects on optical responses, the wide range of laser energy and different pulse durations were used. The fluence and pulse duration-dependent self-reflection under femtosecond laser pulse were measured for WD-Au. By comparing the experimental results, essentiality of consideration of non-thermal kinetics in applications of laser-matter interaction is proposed.