Ultrafast Magnetic Switching of GdFeCo with Electronic Heat Currents

TL;DR

This study demonstrates ultrafast magnetic switching in GdFeCo bilayers induced by electronic heat currents generated through optical irradiation of an Au surface, revealing a new pathway for rapid magnetic control.

Contribution

It introduces a novel mechanism of magnetic switching driven by electronic heat currents in Au/GdFeCo bilayers, with detailed analysis of heat transfer dynamics.

Findings

Electronic heat currents can induce magnetic reversal in GdFeCo.

Heat flux exceeds 2 TW/m^2 during switching.

Ultrafast heat transfer occurs within a few picoseconds.

Abstract

We report the magnetic response of Au/GdFeCo bilayers to optical irradiation of the Au surface. For bilayers with Au thickness greater than 50 nm, the great majority of energy is absorbed by the Au electrons, creating an initial temperature differential of thousands of Kelvin between the Au and GdFeCo layers. The resulting electronic heat currents between the Au and GdFeCo layers last for several picoseconds with energy flux in excess of 2 TW m-2, and provide sufficient heating to the GdFeCo electrons to induce deterministic reversal of the magnetic moment.