Magnetic vortex crystals in frustrated Mott insulator

TL;DR

This paper proposes a simple, robust mechanism for creating magnetic vortex crystals in frustrated Mott insulators through magnetic field-induced condensation of low-energy modes, enriching the landscape of topologically nontrivial spin states.

Contribution

It introduces a new scenario for stabilizing magnetic vortex crystals in frustrated quantum magnets via field-induced condensation of degenerate modes, expanding understanding of emergent topological spin structures.

Findings

Multiple multi-Q condensates are stabilized depending on exchange interactions.

Magnetic vortex crystals are stabilized by symmetric exchange anisotropies.

The phase diagram includes various topologically nontrivial spin configurations.

Abstract

Quantum fluctuations become particularly relevant in highly frustrated quantum magnets and can lead to new states of matter. We provide a simple and robust scenario for inducing magnetic vortex crystals in frustrated Mott insulators. By considering a quantum paramagnet that has a gapped spectrum with six-fold degenerate low energy modes, we study the magnetic field induced condensation of these modes. We use a dilute gas approximation to demonstrate that a plethora of multi-$\mathbf{Q}$ condensates are stabilized for different combinations of exchange interactions. This rich quantum phase diagram includes magnetic vortex crystals, which are further stabilized by symmetric exchange anisotropies. Because magnetic skyrmion and domain wall crystals have already been predicted and experimentally observed, this novel vortex phase completes the picture of emergent crystals of topologically nontrivial spin configurations.