Effect of electron-phonon interaction on the shift and attenuation of optical phonons

TL;DR

This paper investigates how electron-phonon interactions influence the frequency shift and damping of optical phonons in metals, highlighting the role of screening and providing theoretical insights consistent with recent findings.

Contribution

It introduces a detailed analysis of electron-phonon effects on optical phonons, emphasizing the importance of screening and damping mechanisms in metals.

Findings

Optical phonons soften due to screening effects.

Electron-phonon interaction causes additional phonon damping.

Frequency shifts are influenced by electron-phonon coupling.

Abstract

Using the Boltzmann equation for electrons in metals, we show that the optical phonons soften and have a dispersion due to screening in agreement with the results reported recently [M. Reizer, Phys. Rev. B {\bf 61}, 40 (2000)]. Additional phonon damping and frequency shift arise when the electron--phonon interaction is properly included.