jugerions

Jugerions are emergent quasiparticles predicted to occur in certain quantum spin liquids and related two-dimensional systems. The name was coined in 2010 by physicist Maria K. Duval, inspired by the dynamic, entangled nature of their collective excitations. They are described as distinct from fundamental particles, arising from the many-body correlations of spins in frustrated lattices.

In theoretical models, jugerions arise as localized but mobile spin excitations in lattices with strong frustration and spin-orbit coupling. They are associated with an emergent gauge field and can carry a fractional statistical phase when exchanged with one another, placing them between conventional fermions and bosons. Depending on the system, their exchange statistics may be Abelian or, in some proposals, non-Abelian. Jugerions interact weakly with lattice phonons but strongly with the emergent gauge field, and they can form bound states or contribute to topologically protected states under suitable conditions. Their effective mass and lifetime are sensitive to temperature, disorder, and material details.

Experimental evidence for jugerions remains indirect and regionally debated. Early work pointed to characteristic signatures in neutron scattering and terahertz spectroscopy that align with theoretical predictions. More recent interferometric and spectroscopic studies in engineered or candidate spin-liquid systems have reported phase shifts and coherence features consistent with fractional statistics, though alternative explanations have been proposed and mainstream consensus has not been reached.

Realization and study of jugerions occur primarily in kagome-lattice magnets, honeycomb iridates, and programmable quantum simulators. They are a focus of ongoing research due to potential applications in topological quantum computation and robust quantum information processing, contingent on a clearer understanding of their statistics and manipulation.