Symmetry-dependent ultrafast manipulation of nanoscale magnetic domains

TL;DR

This study demonstrates how ultrafast optical pumping induces symmetry-dependent behaviors in nanoscale magnetic domains, revealing that symmetry influences the ultrafast manipulation and recovery of magnetic order.

Contribution

It uncovers the role of symmetry in ultrafast magnetic dynamics, showing distinct responses based on isotropic and anisotropic symmetries using ultrafast x-ray scattering.

Findings

Radial shift observed only in isotropic component after laser pump

Faster recovery time for anisotropic magnetic components

Symmetry influences ultrafast magnetic order manipulation

Abstract

Symmetry is a powerful concept in physics, but its applicability to far-from-equilibrium states is still being understood. Recent attention has focused on how far-from-equilibrium states lead to spontaneous symmetry breaking. Conversely, ultrafast optical pumping can be used to drastically change the energy landscape and quench the magnetic order parameter in magnetic systems. Here, we find a distinct symmetry-dependent ultrafast behaviour by use of ultrafast x-ray scattering from magnetic patterns with varying degrees of isotropic and anisotropic symmetry. After pumping with an optical laser, the scattered intensity reveals a radial shift exclusive to the isotropic component and exhibits a faster recovery time from quenching for the anisotropic component. These features arise even when both symmetry components are concurrently measured, suggesting a correspondence between the excitation and the magnetic order symmetry. Our results underline the importance of symmetry as a critical variable to manipulate the magnetic order in the ultrafast regime.