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arXiv · 1902.05329

Coupled dynamics of long-range and internal spin cluster order in Cu$_{2}$OSeO$_{3}$

R. B. Versteeg·J. Zhu·C. Boguschewski·F. Sekiguchi·A. Sahasrabudhe·K. Budzinauskas·P. Padmanabhan·P. Becker·D. I. Khomskii·P. H. M. van Loosdrecht
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Abstract

Cu$_4$ triplet clusters form the relevant spin entity for the formation of long-range magnetic order in the cluster magnet Cu$_2$OSeO$_3$. Using time-resolved Raman spectroscopy, we probed photoinduced spin and lattice dynamics in this Mott insulator. Multiple ps-decade spin-lattice relaxation dynamics is observed, evidencing a separation of the order parameter dynamics into disordering of long-range and internal spin cluster order. Our study exemplifies the double order parameter dynamics of generalized molecular crystals of charge, spin, and orbital nature.

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R. B. Versteeg, J. Zhu, C. Boguschewski, F. Sekiguchi, A. Sahasrabudhe, K. Budzinauskas, P. Padmanabhan, P. Becker, D. I. Khomskii, P. H. M. van Loosdrecht. 2019-02-14. Coupled dynamics of long-range and internal spin cluster order in Cu$_{2}$OSeO$_{3}$. https://doi.org/10.1103/physrevb.100.064401

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