Reconciling anomalously fast heating rate in ion tracks with low electron-phonon coupling

TL;DR

This paper explains how swift heavy ion tracks form rapidly despite slow electron-phonon coupling by highlighting the role of electron-induced potential energy surface changes in accelerating atoms.

Contribution

It introduces a new perspective that electron energy transfer involves more than electron-phonon coupling, specifically including potential energy surface modifications.

Findings

Electron-phonon coupling alone cannot account for rapid ion track formation.

Electron-induced potential energy surface changes accelerate atoms.

The proposed mechanism resolves the apparent contradiction in energy transfer rates.

Abstract

Formation of swift heavy ion tracks requires extremely fast energy transfer between excited electrons and a lattice. However, electron-phonon energy exchange is too slow, as known from laser-irradiation experiments and calculations. We resolve this contradiction noticing that electron-phonon coupling is not the sole mechanism of energy exchange between electrons and ions: heating of electrons also alters potential energy surface of atoms, accelerating them and increasing their kinetic energy.