Optically probing symmetry breaking in the chiral magnet Cu2OSeO3

Abstract

We report on the linear optical properties of the chiral magnet Cu2OSeO3, specifically associated with the absence of inversion symmetry, the chiral crystallographic structure, and magnetic order. Through spectroscopic ellipsometry, we observe local crystal-field excitations below the charge-transfer gap. These crystal-field excitations are optically allowed due to the lack of inversion symmetry at the Cu sites. Optical polarization rotation measurements were used to study the structural chirality and magnetic order. The temperature dependence of the natural optical rotation, originating in the chiral crystal structure, provides evidence for a finite magneto-electric effect in the helimagnetic phase. We find a large magneto-optical susceptibility on the order of V(540nm)~10^4 rad/(T*m) in the helimagnetic phase and a maximum Faraday rotation of ~165deg/mm in the ferrimagnetic phase. The large value of V can be explained by considering spin cluster formation and the relative ease of domain reorientation in this metamagnetic material. The magneto-optical activity allows us to map the magnetic phase diagram, including the skyrmion lattice phase. In addition to this, we probe and discuss the nature of the various magnetic phase transitions in Cu2OSeO3.

9 pages, 10 figures

References in corpus (8)

• Multiferroics: different ways to combine magnetism and ferroelectricity
• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
• Strong Dzyaloshinskii-Moriya Interaction and Origin of Ferroelectricity in Cu2OSeO3
• The quantum origins of skyrmions and half-skyrmions in Cu2OSeO3
• Ferrimagnetism of the magnetoelectric compound Cu${}_2$OSeO${}_3$ probed by ${}^{77}$Se NMR
• History dependence of the magnetic properties of single-crystal Fe${}_{1-x}$Co${}_x$Si
• Magnetoelectric effects in single crystals of the cubic ferrimagnetic helimagnet Cu2OSeO3

Cited by in corpus (17)

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• Experimental signatures of quantum and topological states in frustrated magnetism
• Room-temperature skyrmion phase in bulk Cu2OSeO3 under high pressures
• Optically driven collective spin excitations and magnetization dynamics in the Néel-type skyrmion host GaV${}_4$S${}_8$
• Laser-controlled real- and reciprocal-space topology in multiferroic insulators
• A tunable time-resolved spontaneous Raman spectroscopy setup for probing ultrafast collective excitation and quasiparticle dynamics in quantum materials
• Ferromagnetic resonance with magnetic phase selectivity by means of resonant elastic x-ray scattering on a chiral magnet
• Strong magneto-optical effects in ACr2O4 A=Fe, Co spinel oxides generated by tetrahedrally coordinated transition metal ions
• Observation of a new light-induced skyrmion phase in the Mott insulator Cu2OSeO3
• Low energy magnon dynamics and magneto-optics of the skyrmionic Mott insulator Cu${}_2$OSeO${}_3$
• Site-specific electronic and magnetic excitations of the skyrmion material Cu${}_2$OSeO${}_3$
• Inelastic light scattering in the spin cluster Mott insulator Cu${}_2$OSeO${}_3$
• Short-wave magnons with multipole spin precession detected in the topological bands of a skyrmion lattice
• Coupled dynamics of long-range and internal spin cluster order in Cu${}_2$OSeO${}_3$
• Quintuplet condensation in the skyrmionic insulator Cu2OSeO3 at ultrahigh magnetic fields
• Structure analysis of high-pressure phase for skyrmion-hosting multiferroic Cu2OSeO3
• Observation of distorted tilted conical phase at the surface of a bulk chiral magnet with resonant elastic x-ray scattering