arXiv subjects

X. -G. Zhou

Publications and source records attributed to X. -G. Zhou.

3 recordsLinked to original sources

arXiv2026

Quintuplet condensation in the skyrmionic insulator Cu2OSeO3 at ultrahigh magnetic fields

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.

cond-mat.str-el↗

arXiv2023

Signatures of a magnetic superstructure phase induced by ultrahigh magnetic fields in a breathing pyrochlore antiferromagnet

The mutual coupling of spin and lattice degrees of freedom is ubiquitous in magnetic materials and potentially creates exotic magnetic states in response to the external magnetic field. Particularly, geometrically frustrated magnets serve as a fertile playground for realizing magnetic superstructure phases. Here, we observe an unconventional two-step magnetostructural transition prior to a half-magnetization plateau in a breathing pyrochlore chromium spinel by means of state-of-the-art magnetization and magnetostriction measurements in ultrahigh magnetic fields available up to 600 T. Considering a microscopic magnetoelastic theory, the intermediate-field phase can be assigned to a magnetic superstructure with a three-dimensional periodic array of 3-up-1-down and canted 2-up-2-down spin molecules. We attribute the emergence of the magnetic superstructure to a unique combination of the strong spin-lattice coupling and large breathing anisotropy.

cond-mat.mtrl-sci↗

arXiv2021

Particle-hole symmetry breaking in a spin-dimer system TlCuCl$_3$ observed at 100 T

The entire magnetization process of TlCuCl$_3$ has been experimentally investigated up to 100 T employing the single-turn technique. The upper critical field $H_{c2}$ is observed to be 86.1 T at 2 K. A convex slope of the $M$-$H$ curve between the lower and upper critical fields ($H_{c1}$ and $H_{c2}$) is clearly observed, which indicates that a particle-hole symmetry is broken in TlCuCl$_3$. By quantum Monte Carlo simulation and the bond-operator theory method, we find that the particle-hole symmetry breaking results from strong inter-dimer interactions.

cond-mat.str-el↗