Influence of nanoparticle surface and shape on the dipole magnetic absorption of ultrashort laser pulses

TL;DR

This paper develops a theory on how nanoparticle shape and surface affect magnetic energy absorption from ultrashort laser pulses, highlighting the influence of particle geometry, orientation, and electron mean free path.

Contribution

It introduces a comprehensive theoretical model analyzing the impact of nanoparticle shape and surface on magnetic absorption under ultrashort laser irradiation.

Findings

Absorption increases significantly when electron mean free path matches particle size.

Particle shape and orientation strongly influence magnetic energy absorption.

Comparison of Drude and kinetic models shows consistent results.

Abstract

The theory on the magnetic field energy absorption by metal nanoparticles of a nonspherical shape irradiated with ultrashort laser pulses of different duration is developed. The effect of both the particle surface and the particle shape on the absorbed energy is studied. For the particles having an oblate or prolate spheroidal shape, the dependence of this energy on the orientation of the magnetic field upon a particle, the degree of its deviation from a spherical shape, a pulse duration, and the carrier frequency of the laser ray are found. A significant increase in the absorption is established when an electron mean free path coincides with the size of the particle. The Drude and kinetic approaches are used and the results are compared with each other.