Research: A classical chiral spin liquid from chiral interactions on the pyrochlore lattice

Classical spin liquids are highly-correlated paramagnetic phases whose low-temperature physics can be effectively described by emergent gauge theories which often harbour fractionalized excitations. In this work, we discuss a model composed of chiral three-body spin interactions on the pyrochlore lattice that realizes a novel classical chiral spin liquid whose excitations are not only fractionalized but also display a fracton-like behaviour. We demonstrate that the low-energy states of this phase are captured by an effective gauge theory which possesses a divergence-free condition and an additional chiral term that constrains the total flux of the fields through a single tetrahedron. The divergence-free constraint on the gauge fields results in two-fold pinch points in the spin structure factor and the identification of bionic charges as excitations of the system. We also show that this spin liquid can be stabilized for when considering an additional antiferromagnetic Heisenberg interaction between nearest-neighbours. 

D. Lozano-Gómez, Y. Iqbal, M. Vojta,
A classical chiral spin liquid from chiral interactions on the pyrochlore lattice,
Nat. Commun. 15, 10162 (2024) (arXiv)