Observation of Magnetic Helicoidal Dichroism with Extreme Ultraviolet Light Vortices
Mauro Fanciulli, Matteo Pancaldi, Emanuele Pedersoli, Mekha Vimal, David Bresteau, Martin Luttmann, Dario De Angelis, Primož Rebernik Ribič, Benedikt Rösner, Christian Dávid, Carlo Spezzani, Michele Manfredda, R. C. Sousa, Lucian Prejbeanu, L. Vila, B. Diény, G. De Ninno, Flavio Capotondi, M. Sacchi, Thierry Ruchon
Abstract
We report on the experimental evidence of magnetic helicoidal dichroism, observed in the interaction of an extreme ultraviolet vortex beam carrying orbital angular momentum with a magnetic vortex. Numerical simulations based on classical electromagnetic theory show that this dichroism is based on the interference of light modes with different orbital angular momenta, which are populated after the interaction between light and the magnetic topology. This observation gives insight into the interplay between orbital angular momentum and magnetism and sets the framework for the development of new analytical tools to investigate ultrafast magnetization dynamics.