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MA: Fachverband Magnetismus

MA 16: Magnonics I

MA 16.5: Vortrag

Dienstag, 19. März 2024, 10:30–10:45, EB 107

Femtosecond coupled spin and charge dynamics in an antiferromagnet — •Moritz Cimander, Volker Wiechert, Julian Bär, and Davide Bossini — Universität Konstanz, Konstanz, Germany

The research field adressing spin dynamics in magnets has gained recently a remarkable popularity. Especially antiferromagnets are of interest in view of high magnon frequencies in the THz regime, the lack of stray field and aboundant availibility in nature[1]. However fundamental questions regarding the control of coherent spin dynamics and a possible coupling of charges have still to be solved.

As previously demonstrated, coherent magnons can be excited in a nickel oxide single crystal via optical pumping of an exciton-magnon transition[2]. However, the resulting dynamics of the electronic system has not yet been explored. In particular, we set out to establish the possibility of a coupling between the photoinduced coherent magnons and the optical properties of the electronic system.

For this purpose, we developed a cryogenic magneto-optical pump-probe spectrometer in the VIS-NIR region. This apparatus enabled the detection of optical and magneto-optical dynamics, triggered by resonant and off-resonant excitation of the exciton-magnon and allows the coherent manipulation of the transient transmissivity by magnons. A systematic investigation of the observed effect as a function of several experimental parameters will be presented and discussed.

[1] M. B. Junglfleisch. et al.: Phys. Lett. A 382, 865 (2018)

[2] D. Bossini et al.: Phys. Rev. Lett. 127, 077202 (2021)

Keywords: antiferromagnet; spin-charge coupling; magneto-optic spin control; spin dynamics