Nanoscale confinement of all-optical switching in TbFeCo using plasmonic antennas

TL;DR

This paper demonstrates nanoscale all-optical magnetic switching in TbFeCo using plasmonic antennas, achieving 53 nm domain sizes, which advances the potential for high-density optical magnetic data storage.

Contribution

It introduces a method to confine all-optical magnetic switching to nanoscale regions using plasmonic antennas, surpassing diffraction limits.

Findings

Achieved 53 nm magnetic domain switching.

Used x-ray holography to image magnetic reversal.

Demonstrated potential for high-density optical data storage.

Abstract

All-optical switching (AOS) of magnetic domains by femtosecond laser pulses was first observed in the transition metal-rare earth (TM-RE) alloy GdFeCo1-5; this phenomenon demonstrated the potential for optical control of magnetism for the development of ever faster future magnetic recording technologies. The technological potential of AOS has recently increased due to the discovery of the same effect in other materials, including RE-free magnetic multilayers6,7. However, to be technologically meaningful, AOS must compete with the bit densities of conventional storage devices, restricting optically-switched magnetic areas to sizes well below the diffraction limit. Here, we demonstrate reproducible and robust all-optical switching of magnetic domains of 53 nm size in a ferrimagnetic TbFeCo alloy using gold plasmonic antenna structures. The confined nanoscale magnetic reversal is imaged around and beneath plasmonic antennas using x-ray resonant holographic imaging. Our results demonstrate the potential of future AOS-based magnetic recording technologies.