Magnetic helicoidal dichroism in reflection by magnetic vortices

Abstract

Identifying and imaging spin textures of ever more complex magnetic structures has become a major challenge in the past decade, especially at ultrashort timescales. Most of current approaches are based on the analysis of their polarization and magnetization-dependent reflectivities. Based on our joint publication XXX XX XXXXXX, we introduce a different concept, centered on the coupling of magnetic structures with light beams carrying orbital angular momentum (OAM). Upon reflection by a magnetic vortex, an incoming beam with a unique value $\ell$ of OAM gets enriched in the neighboring OAM modes $\ell \pm 1$. It results in anisotropic far-field images, which are identified as a Magnetic Helicoidal Dichroism (MHD) signal. Their analysis allow to retrieve the complex magneto-optical constants with excellent precision. This method, which does not require any polarization-resolved analysis, is promising for a quick identification of spin textures, including with attosecond to femtosecond time resolutions.

arXiv comment4 figures, 1 table, 5 pages

References in corpus (6)

• Vowel recognition with four coupled spin-torque nano-oscillators
• Electrical switching of vortex core in a magnetic disk
• Petahertz Spintronics
• Magnetic Vortex Core Dynamics in a Ferromagnetic Dot
• X-ray imaging of the dynamic magnetic vortex core deformation
• Chirality in magnetic multilayers probed by the symmetry and the amplitude of dichroism in X-ray resonant magnetic scattering