Regensburg 2022 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 21: Terahertz Spintronics
MA 21.5: Vortrag
Mittwoch, 7. September 2022, 10:30–10:45, H43
THz spin dynamics in antiferromagnetic Mn2Au — •Yannic Behovits1,2, Alexander Chekhov1,2, Stanislav Bodnar3, Mathias Kläui3, Martin Jourdan3, and Tobias Kampfrath1,2 — 1Freie Universität Berlin, Insitut für Experimentalphysik, 14195 Berlin, Germany — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Physikalische Chemie, 14195 Berlin, Germany — 3Johannes-Gutenberg-Universität, Institut für Physik, 55122 Mainz, Germany
In metallic antiferromagnets, intrinsic terahertz (THz) magnons may allow high-speed spin information processing. For CuMnAs and Mn2Au, switching of the Néel vector has been demonstrated by using pulsed electrical currents and free-space THz pulses [1,2]. The switching was attributed to the current-induced Néel spin-orbit torque (NSOT)[3]. However, the underlying spin dynamics have not been observed on picosecond timescales. Here, we employ a THz-pump optical-probe setup to investigate dynamics of antiferromagnetic order induced by NSOT in Mn2Au. We observe a signal proportional to the driving THz field, which is consistent with NSOT-driven spin dynamics both in frequency and symmetry. Our results indicate a strongly damped magnon mode at 0.6 THz. By using a simple model, we can extract material properties and estimate the field strengths required for picosecond rotation of the antiferromagnetic order.
[1] K. Olejnik et al., Sci. Adv., 4(3): p. eaar3566 (2018) [2] S. Yu. Bodnar et al., Nat. Commun., 9(1): p. 348. (2018) [3] J. Zelezny et al., PRL, 113(15): p. 157201 (2014)