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INSP

Tracking the magnetization dynamics of a magnetic vortex by magnetic helicoidal dichroism – Highlight CEA-IRAMIS – May 22 2025

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Micro- and nanostructures of magnetic materials are the basis for a wide range of technological applications, from sensors to data storage. New methods for measuring and controlling the dynamics of their magnetization are therefore worthy of research. A widely-used technique for measuring magnetization is magnetic circular dichroism (MCD), i.e. the measurement of the difference in response of a magnetic system subjected to a right- or left-hand circularly polarized light beam.

A broad international collaboration, including Maurizio Sacchi from INSP, has shown that it is possible to obtain picosecond-scale time-resolved magnetic helicoidal dichroism measurements with light pulses carrying an orbital angular momentum (helical wave plane). This new method is particularly useful for monitoring the magnetization dynamics of magnetic vortices.

 

Reference :

Magnetic vortex dynamics probed by time-resolved magnetic helicoidal dichroism
M. Fanciulli, M. Pancaldi, A.-E. Stanciu, M. Guer, E. Pedersoli, D. De Angelis, P. R. Ribič, D. Bresteau, M. Luttmann, P. Carrara, A. Ravindran, B. Rösner, C. David, C. Spezzani, M. Manfredda, R. Sousa, L. Vila, I. L. Prejbeanu, L. D. Buda-Prejbeanu, B. Dieny, G. De Ninno, F. Capotondi, T. Ruchon, and M. Sacchi, Phys. Rev. Lett. 134 (2025) 156701.