Electric Current Induced Ultrafast Demagnetization

TL;DR

This paper demonstrates that picosecond electrical pulses can induce ultrafast demagnetization in Co/Pt multilayers, revealing different dynamics compared to optical heating due to electron-phonon interaction differences.

Contribution

It introduces a method for electrical ultrafast demagnetization using picosecond pulses and compares its dynamics to optical methods, highlighting the role of electron-phonon interactions.

Findings

Electrical pulses cause ultrafast reduction in magnetic moment.

Demagnetization dynamics differ between electrical and optical heating.

Electron-phonon interactions depend on initial electron energy and number.

Abstract

We report the magnetic response of Co/Pt multilayers to picosecond electrical heating. Using photoconductive Auston switches, we generate electrical pulses with 5.5 picosecond duration and hundreds of pico-Joules to pass through Co/Pt multilayers. The electrical pulse heats the electrons in the Co/Pt multilayers and causes an ultrafast reduction in the magnetic moment. A comparison between optical and electrically induced demagnetization of the Co/Pt multilayers reveals significantly different dynamics for optical vs. electrical heating. We attribute the disparate dynamics to the dependence of the electron-phonon interaction on the average energy and total number of initially excited electrons.