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O: Fachverband Oberflächenphysik

O 37: Poster Session III: Surface magnetism III

O 37.3: Poster

Tuesday, March 2, 2021, 10:30–12:30, P

Ultrafast demagnetization dynamics including spin resolved charge and heat transport. — •Sanjay Ashok, Sebastian T. Weber, Christopher Seibel, Johan Briones, and Bärbel Rethfeld — Fachbereich Physik and OPTIMAS Research Center, TU Kaiserslautern, Kaiserslautern, Germany

Ultrafast Demagnetization of metallic ferromagnets due to excitation with a femtosecond laser pulse was discovered by Beaurepaire et al. in 1996 [1]. In case of metallic magnets with thickness lesser than pene- tration depth of the laser, the film is heated homogeneously. Therefore, due to absence of temperature and density gradients within the material there would be no heat- or charge-currents. For thicker magnetic metals, the heating is not uniform and therefore one needs to distinguish the resulting role of heat and spin-resolved charge transport in ultrafast de- and re- magnetization [2]. This is a pivotal issue owing to rich possibilities in its applications.

Here we study the role of spin-resolved charge and heat transport in ultrafast demagnetization of thick magnetic metal using Thermodynamic µT-model [3] and obtain spatial and temporal evolution of magnetization. We also present the role of applied fluence and trans- port channels.

[1] E. Beaurepaire, J.-C. Merle, A. Daunois and J.-Y. Bigot, Phys. Lett. 76, 4250 (1996).

[2] Y. Liu et al. JMMM 502, 166477 (2020).

[3] B. Y. Mueller and B. Rethfeld, Phys. Rev. B 90, 144420 (2014).