Measuring the electrical conductivity of warm dense gold using ultrafast THz radiation*

Electrical conductivity contains important information of warm dense matter (WDM), such as conduction electron density, ionic structure factor, and electron-ion interaction potentials [1]. With the advent of ultrafast lasers, WDM can be created by isochoric laser excitation of solids, and a great amount of efforts have been made to determine their AC conductivity at optical frequencies [2-3]. However, the direct measurement of DC conductivity of such WDM is still missing. Recently, we have developed an experimental platform to study the electrical conductivity of laser heated WDM using single-shot THz time domain spectroscopy [4-5], whose oscillation frequency is significantly below the electron-electron and electron-ion scattering frequency. This provides a direct approach to determining the DC conductivity of WDM. The experimental results of isochorically heated warm dense gold thin films will be presented and compared with previous studies at optical frequencies.

1. A. Ng et al., PRE 94, 033213 (2016)
2. K. Widmann et al., PRL 92, 125002 (2004)
3. Z. Chen et al., PRL 110, 135001 (2013)
4. B. Russell et al., Opt. Expr. 25, 16140 (2017)
5. B. K. Ofori-Okai et al., to be appeared in RSI