All-optical switching on the nanometer scale excited and probed with femtosecond extreme ultraviolet pulses

TL;DR

This study demonstrates ultrafast all-optical magnetic switching at the nanometer scale using femtosecond extreme ultraviolet pulses to excite and probe magnetic gratings in a GdFe alloy, overcoming wavelength limitations.

Contribution

It introduces a method to achieve and observe ultrafast all-optical magnetic switching at nanometer scales using EUV pulses and diffraction techniques.

Findings

Ultrafast magnetic gratings with 87 nm periodicity were excited.

All-optical switching was conclusively demonstrated on the nanometer scale.

The technique enables real-time observation of magnetization dynamics.

Abstract

Ultrafast control of magnetization on the nanometer length scale, in particular all-optical switching, is key to putting ultrafast magnetism on the path towards future technological application in data storage technology. However, magnetization manipulation with light on this length scale is challenging due to the wavelength limitations of optical radiation. Here, we excite transient magnetic gratings in a GdFe alloy with a periodicity of 87 nm by interference of two coherent femtosecond light pulses in the extreme ultraviolet spectral range at the free electron laser facility FERMI. The subsequent ultrafast evolution of the magnetization pattern is probed by diffraction of a third, time-delayed pulse tuned to the Gd N-edge at a wavelength of 8.3 nm. By examining the simultaneously recorded first and second diffraction orders and by performing reference real-space measurements with a wide-field magneto-optical microscope with femtosecond time resolution, we can conclusively demonstrate the ultrafast emergence of all-optical switching on the nanometer length scale.