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.
@article{arxiv.1409.1280,
title = {Nanoscale confinement of all-optical switching in TbFeCo using plasmonic antennas},
author = {TianMin Liu and Tianhan Wang and Alexander H. Reid and Matteo Savoini and Xiaofei Wu and Benny Koene and Patrick Granitzka and Catherine Graves and Daniel Higley and Zhao Chen and Gary Razinskas and Markus Hantschmann and Andreas Scherz and Joachim Stöhr and Arata Tsukamoto and Bert Hecht and Alexey V. Kimel and Andrei Kirilyuk and Theo Rasing and Hermann A. Dürr},
journal= {arXiv preprint arXiv:1409.1280},
year = {2014}
}