Plasmon-induced demagnetization and magnetic switching in nickel nanoparticle arrays

TL;DR

This paper demonstrates how femtosecond laser pulses can manipulate magnetization in nickel nanoparticle arrays through plasmon-induced heating, leading to demagnetization or magnetic switching depending on conditions.

Contribution

It reveals the role of collective surface plasmon resonances in controlling magnetization states in nickel nanoparticles, a novel mechanism for ultrafast magnetic manipulation.

Findings

Surface plasmon resonances trigger demagnetization or switching.

Heating to Curie temperature explains magnetic effects.

Model confirms correlation between plasmon excitation and magnetization change.

Abstract

We report on the manipulation of magnetization by femtosecond laser pulses in a periodic array of cylindrical nickel nanoparticles. By performing experiments at different wavelength, we show that the excitation of collective surface plasmon resonances triggers demagnetization in zero field or magnetic switching in a small perpendicular field. Both magnetic effects are explained by plasmon-induced heating of the nickel nanoparticles to their Curie temperature. Model calculations confirm the strong correlation between the excitation of surface plasmon modes and laser-induced changes in magnetization.