Direct observation of enhanced electron-phonon coupling in copper nanoparticles in the warm-dense matter regime
| Autor: | Nguyen, Quynh L. D., Simoni, Jacopo, Dorney, Kevin M., Shi, Xun, Ellis, Jennifer L., Brooks, Nathan J., Hickstein, Daniel D., Grennell, Amanda G., Yazdi, Sadegh, Campbell, Eleanor E. B., Tan, Liang Z., Prendergast, David, Daligault, Jerome, Kapteyn, Henry C., Murnane, Margaret M. |
|---|---|
| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Warm-dense matter (WDM) is a highly-excited state that lies at the confluence of solids, plasmas, and liquids and that cannot be described by equilibrium theories. The transient nature of this state when created in a laboratory, as well as the difficulties in probing the strongly-coupled interactions between the electrons and the ions, make it challenging to develop a complete understanding of matter in this regime. In this work, by exciting isolated ~8 nm nanoparticles with a femtosecond laser below the ablation threshold, we create uniformly-excited WDM. We then use photoelectron spectroscopy to track the instantaneous electron temperature and directly extract the strongest electron-ion coupling observed experimentally to date. By directly comparing with state-of-the-art theories, we confirm that the superheated nanoparticles lie at the boundary between hot solids and plasmas, with associated strong electron-ion coupling. This is evidenced both by the fast energy loss of electrons to ions, as well as a strong modulation of the electron temperature by acoustic oscillations in the nanoparticle. This work demonstrates a new route for experimental exploration and theoretical validation of the exotic properties of WDM. Comment: 12 pages, 4 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|