Quintuplet condensation in the skyrmionic insulator Cu2OSeO3 at ultrahigh magnetic fields
Published: Sep 16, 2025
Last Updated: Sep 16, 2025
Authors:T. Nomura, I. Rousochatzakis, O. Janson, M. Gen, X. -G. Zhou, Y. Ishii, S. Seki, Y. Kohama, Y. H. Matsuda
Abstract
We report ultrahigh magnetic field Faraday rotation results on the chiral helimagnet Cu2OSeO3, the first Mott insulator showing skyrmion lattice phases and a linear magnetoelectric effect. Between 180 and 300 T, we find signatures of a Bose-Einstein condensation (BEC) of magnons, which can be described as a canted XY ferrimagnet. Due to the magnetoelectric coupling, the transverse magnetic order of the indivual Cu2+ spins is accompanied by a characteristic dome-like electric polarization which is crucial for the observation of the condensate via the Faraday rotation effect.