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SYAS: Symposium Attosecond and coherent spins: New frontiers
SYAS 1: Attosecond and Coherent Spins: New Frontiers
SYAS 1.2: Hauptvortrag
Montag, 16. März 2020, 15:30–16:00, HSZ 02
Ab-initio treatment of ultrafast spin-dynamics — •Sangeeta Sharma1 and J. K. Dewhurst2 — 1Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Strasse 2A, 12489 Berlin, Germany — 2Max planck Inst. Halle, Weinberg 2, 06120 Halle
I will talk about all-optical switching of long-range magnetic order. The type of coupling between the constituent atoms of a magnetic solid, usually ferromagnetic (FM) or anti-ferromagnetic (AFM), is a fundamental property of any magnetic material. This coupling is governed by the exchange interaction, for which the time scale of a typical magnetic material is of the order of a few 100s of femtoseconds. In our work, using time-dependent density functional theory (TDDFT), we demonstrate that a rich control over magnetization at sub-exchange time scales (of the order of few tens of femtoseconds) is possible[1,2,3,4]. This even includes changing the magnetic order from AFM to FM[5]. By investigating a wide range of multi-sublattice magnetic materials we are able to formulate three simple rules that predict the qualitative dynamics of magnetization for ferromagnetic, anti-ferromagnetic, and ferri-magnetic materials on sub-exchange time scales.
[1] Shokeen et al. Phys. Rev. Lett. 119, 107203 (2017) [2] Elliott et al. Scientific Reports 6, 38911 (2016) [3] Chen et al. Phys. Rev. Lett. 122, 067202 (2019) [4] Siegrist et al. Nature 571, 240 (2019) [5] Dewhurst et al. Nano Lett. 18, 1842, (2018)