TITLE:Microscopic Pathways of Light‑Induced Magnetism in Cr₂Ge₂Te₆
AUTHOR: Theodor Griepe, Madrid Institute of Material Sciences
WHEN: May, 14 - 12PM
WHERE: Salón de Actos, ICMM
ABSTRACT: The ever‑growing demand for energy‑efficient information technologies is driving intense efforts to replace charge‑based electronic operations with magnetic and spin‑based functionalities, which promise reduced energy dissipation and non‑volatile information processing. Two‑dimensional (2D) materials are particularly promising in this context due to pronounced surface and edge effects, precise control of thickness and interfaces, and the presence of geometrical and topological constraints.
In this talk, I focus on light‑induced ultrafast magnetization dynamics in the van der Waals ferromagnet Cr₂Ge₂Te₆ (CGT), a prototypical 2D magnetic semiconductor. Ultrafast magnetic processes unfold on femtosecond to nanosecond timescales and arise from a complex interplay between electronic excitations, spin dynamics, lattice motion, and heat transport. CGT is an attractive model system due to its relatively high Curie temperature and the intricate competition between Coulomb exchange, crystal‑field splitting, and spin–orbit–driven effects, which together generate a rich hierarchy of energy scales and optical selection rules.
I will present experimental techniques capable of resolving element‑, orbital‑, and symmetry‑specific ultrafast dynamics, alongside theoretical and modeling approaches that capture light‑induced nonequilibrium behavior in CGT from attoseconds to nanoseconds, providing a microscopic framework for understanding ultrafast spin, lattice, and energy dynamics in 2D ferromagnetic materials.
