3 years ago

Temperature Dependence of Electron–Phonon Interactions in Gold Films Rationalized by Time-Domain Ab Initio Analysis

Temperature Dependence of Electron–Phonon Interactions in Gold Films Rationalized by Time-Domain Ab Initio Analysis
Patrick E. Hopkins, Hao Dong, Oleg V. Prezhdo, Ashutosh Giri, Linqiu Li, Xin Zhou
The nonequilibrium dynamics of excited electrons in metals is probed by ultrafast laser measurements. Using a real-time Kohn–Sham time-dependent density functional theory and nonadiabatic molecular dynamics, we report direct modeling of such experiments, rationalizing the observed temperature dependence. Focusing on thin gold films, we analyze the effect of temperature on film structure, electronic state densities, nonadiabatic electron–phonon coupling, elastic electron–phonon scattering times, and electron–phonon relaxation rates. The effective electron–phonon coupling constants calculated at different temperatures are in good agreement with the values deduced from experiments and an alternative theory. A temperature increase accelerates both inelastic and elastic electron–phonon scattering and allows a larger number of higher-frequency phonon modes to couple to the electronic subsystem. The inelastic electron–phonon coupling is largest between nearest states, indicating that carrier relaxation involves transitions over small energy increments. In contrast, the elastic electron–phonon scattering is strongest for pairs of electronic states that are distant in energy. The electron–phonon interactions exhibit mild energy dependence, with both nonadiabatic electron–phonon coupling and elastic electron–phonon scattering times decreasing with increasing electron excitation energy. The detailed ab initio analysis of the electron–phonon interactions emphasizes the nonequilibrium nature of the relaxation processes and provides important insights into the electron–phonon energy exchange in metal films in general.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b05211

DOI: 10.1021/acs.jpcc.7b05211

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.