15–20 May 2022
Hotel Hermitage, La Biodola Bay, Elba Island, Italy
Europe/Rome timezone

Inertial spin dynamics in epitaxial cobalt films

17 May 2022, 18:50
1h 10m
Hotel Hermitage, La Biodola Bay, Elba Island, Italy

Hotel Hermitage, La Biodola Bay, Elba Island, Italy

Biodola Bay 57037 Portoferraio (LI) Isola d’Elba - Italy

Speaker

Dr Vivek Unikandanunni (Stockholm University)

Description

We investigate the spin dynamics driven by terahertz magnetic fields in epitaxial thin films of
cobalt in its three crystalline phases. The terahertz magnetic field generates a torque on the magnetization which causes it to precess for about 1 ps, with a sub-picosecond temporal lag from the driving force. Then, the magnetization undergoes natural damped THz oscillations at a frequency characteristic of the crystalline phase (see fig. 1). We describe the experimental observations solving the inertial Landau-Lifshitz-Gilbert equation. Using the results from the relativistic theory of magnetic inertia, we find that the angular momentum relaxation time η is the only material parameter needed to describe all the experimental evidence. Our experiments suggest a proportionality between η and the strength of the magneto-crystalline anisotropy.

Primary author

Dr Vivek Unikandanunni (Stockholm University)

Co-authors

Dr Marco Asa (Politecnico di Milano Technical University) Dr Rajasekhar Medapalli (Lancaster University) Dr Edoardo Albisetti (Politecnico di Milano Technical University) Dr Daniela Petti (Politecnico di Milano Technical University) Prof. Riccardo Bertacco (Politecnico di Milano Technical University) Prof. Eric Fullerton (University of California San Diego) Prof. Stefano Bonetti (Stockholm University)

Presentation materials

There are no materials yet.