Ultrafast demagnetization of ferromagnetic transition metals: The role of the Coulomb interaction

TL;DR

This paper demonstrates that electron-electron scattering, within the Elliott-Yafet mechanism, can explain ultrafast demagnetization in ferromagnetic metals, challenging the previous focus on electron-phonon interactions.

Contribution

It introduces the role of electron-electron scattering in the Elliott-Yafet mechanism as a key factor in ultrafast demagnetization, expanding beyond electron-phonon processes.

Findings

Electron-electron scattering can account for ultrafast demagnetization.

The mechanism explains time-resolved magneto-optical Kerr effect measurements.

No need to invoke a phononic spin bath for demagnetization.

Abstract

The Elliott-Yafet mechanism is arguably the most promising candidate to explain the ultrafast demagnetization dynamics in ferromagnetic transition metals on timescales on the order of 100 femtoseconds. So far, only electron-phonon scattering has been analyzed as the scattering process needed to account for the demagnetization due to the Elliott-Yafet mechanism. We show for the first time that the electron-electron scattering contribution to the Elliott-Yafet mechanism has the potential to explain time-resolved magneto-optical Kerr effect measurements on thin magnetic cobalt and nickel films, without reference to a phononic "spin bath."