Group Seminar 2025/26

ABSTRACT: In quantum magnetism, much attention has been paid to spin-half systems, where quantum fluctuations are large and can destabilize long-range order leading to liquid-like ground states. However, for systems with S>1/2, an enlarged local Hilbert space can combine with exchange interactions to promote complex order and dynamics not described by conventional semiclassical dipolar spin physics.

In this talk, I will demonstrate the existence of a fluid-like floating phase in a frustrated triangular antiferromagnet with localized quadrupolar excitations. By combining neutron scattering with Monte Carlo simulations and SU(N) kernel polynomial method spin wave theory (KPM-SWT), I will further show that the low temperature phase diagram can be understood in terms of the proliferation of spin clusters which crystallize to form a high-field multi-Q phase. Finally, I will argue that anisotropic two-dimensional magnets offer a fertile playground at the interface of quantum and classical physics, where hidden order, bound states, and quasiparticle decay can be found alongside classical fluid-like phases.