Weak electron-phonon coupling in the early alkali atomic wires

TL;DR

This study investigates the electron-phonon interactions in lithium and sodium atomic wires, revealing that s-like electronic states near the Fermi level exhibit very weak coupling to phonons, especially transverse modes.

Contribution

It demonstrates that s-like states at the Fermi level lead to weak electron-phonon coupling in one-dimensional alkali metal wires, contrasting with materials containing d-like states.

Findings

Weak coupling of s-like states to longitudinal phonons

No coupling of s-like states to transverse phonons

Reinforces the link between electronic state character and electron-phonon interaction strength

Abstract

The structural, electronic and vibrational properties of atomic wires composed of the early alkali metals lithium and sodium are studied using density functional perturbation theory. The s-like electronic states near the Fermi level couple very weakly to longitudinal acoustic phonons and not at all to the transverse acoustic phonons, which results in a weak overall electron-phonon coupling. The results are compared to earlier studies on the electron-phonon coupling in metallic atomic wires and reinforces the idea that s-like states at the Fermi level give rise to weak electron-phonon coupling in one-dimension, in contrast with materials containing d-like states at the Fermi level which have correspondingly larger electron-phonon coupling due to interactions with transverse phonons.