Optical conductivity of visons in Z2 spin liquids close to a VBS transition on the kagome lattice

Abstract

We consider Z2 spin liquids on the kagome lattice on the verge of a valence bond solid (VBS) transition, where vortex excitations carrying Z2 magnetic flux - so-called visons - condense. We show that these vison excitations can couple directly to the external electromagnetic field, even though they carry neither spin nor charge. This is possible via a magneto-elastic coupling mechanism recently identified by Potter et al and Hao. For the case of transitions to a 36-site unit cell VBS state the corresponding finite ac-conductivity has a specific power law frequency dependence, which is related to the crossover exponent of the quantum critical point. The visons' contribution to the optical conductivity at transitions to VBS states with a 12-site unit cell vanishes, however.

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Cited by in corpus (10)

• A Field Guide to Spin Liquids
• Dynamics of visons and thermal Hall effect in perturbed Kitaev models
• Quantum Spin Liquid in a Breathing Kagome Lattice
• Theory of electronic magnetoelectric coupling in $d^5$ Mott insulators
• ${\mathbb{Z}}_2$ gauge theory for valence bond solids on the kagome lattice
• Electric field control of emergent electrodynamics in quantum spin ice
• Magnetic terahertz resonances above the Néel temperature in the frustrated kagome antiferromagnet averievite
• Converting electrons into emergent fermions at a superconductor-Kitaev spin liquid interface
• Signatures of spin-triplet excitations in optical conductivity of valence bond solids
• Low-energy optical absorption in correlated insulators: Projected sum rules and the role of quantum geometry