Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 47: Quantum Magnets, Molecular Magnets and Skyrmions

TT 47.6: Vortrag

Mittwoch, 3. April 2019, 16:15–16:30, H23

Coupled dynamics of long-range and internal spin cluster order in Cu₂OSeO₃ — •Rolf B. Versteeg¹, Jingyi Zhu¹, Christoph Boguschewski¹, Fumiya Sekiguchi¹, Anuja Sahasrabudhe¹, Kestutis Budzinauskas¹, Petra Becker², Daniel I. Khomskii¹, and Paul H.M. van Loosdrecht¹ — ¹University of Cologne, Institute of Physics 2, Zülpicher Straße 77, D-50937 Cologne — ²University of Cologne, Institute of Geology and Mineralogy, Zülpicher Straße 49b, D-50674 Cologne

Quantum materials with multiple length scales for electronic interactions lead to the self-organization of long-range ordered "molecules" of charge, spin, and orbital nature. The order to disorder phase transition pathways in such quantum materials comprises disordering of both the order inside the individual molecules or "clusters", as well as the emerging long-range order.

Here, we reveal optically induced dual order parameter dynamics in the cluster magnet Cu₂OSeO₃ (Ref. [1,2,3]) using time-resolved spontaneous Raman spectroscopy. (Ref. [4]) Multiple ps-decade spin-lattice relaxation dynamics is observed, which evidences a separation of the magnetic order parameter dynamics into disordering of long-range and internal spin cluster order. Our study demonstrates the dual nature of long-range and internal cluster order dynamics in cluster magnets.
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O. Janson et al., Nat. Commun. 5, 5376 (2014)
R. B. Versteeg et al., Phys. Rev. B 94, 094409 (2016)
R. B. Versteeg et al., Struct. Dyn. 5, 044301 (2018)