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MA: Fachverband Magnetismus
MA 8: Ultrafast Magnetization Effects I
MA 8.11: Vortrag
Montag, 27. März 2023, 17:45–18:00, HSZ 04
Nonequilibrium Magnons from Hot Electrons in Antiferromagnetic Systems — Marion Barbeau1, Mikhail Titov2, Mikhail Katsnelson2, and •Alireza Qaiumzadeh1 — 1Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway — 2Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, The Netherlands
We describe a nonthermal magnon activation mechanism in antiferromagnetic (AFM) systems via locally equilibrated spin-unpolarized hot electrons excited by an ultrafast intense laser pulse. We employ a quantum kinetic equation that takes into account a direct electron-magnon scattering channel in either bulk AFM metal or at the interface of the AFM/normal-metal heterostructure. The mechanism is responsible for the nonequilibrium population of AFM magnon modes on a subnanosecond timescale, which are formed shortly after the local thermalization of hot electrons by Coulomb interactions. Nonequilibrium magnon populations can be additionally manipulated by applying an external magnetic field. Our work paves the way toward spin dynamics control in AFM systems via the ultrafast manipulation of out-of-equilibrium magnon excitations [1].
[1] M. M. S. Barbeau, M. Titov, M. I. Katsnelson, A. Qaiumzadeh, arXiv:2209.03469v1