Ab initio determination of effective electron-phonon coupling factor in copper

TL;DR

This paper calculates the effective electron-phonon coupling factor in copper from first principles and demonstrates its impact on ultrafast laser heating simulations, showing faster energy transfer compared to phenomenological models.

Contribution

It introduces an ab initio method to determine the electron-phonon coupling factor and integrates it into MD-TTM simulations for more accurate ultrafast heating modeling.

Findings

Faster electron temperature decrease with ab initio coupling factor

More rapid lattice heating observed in simulations

Method applicable to other metals

Abstract

The electron temperature dependent electron density of states, Fermi-Dirac distribution, and electron-phonon spectral function are computed as prerequisites before achieving effective electron-phonon coupling factor. The obtained coupling factor is implemented into a molecular dynamics (MD) and two-temperature model (TTM) coupled simulation of femtosecond laser heating. By monitoring temperature evolutions of electron and lattice subsystems, the result utilizing coupling factor from ab initio calculation, shows a faster decrease of electron temperature and increase of lattice temperature than those using coupling factor from phenomenological treatment. The approach of calculating coupling factor and its implementation into MD-TTM simulation is applicable to other metals.