Vison and photon electrodynamics in quantum spin ice

We investigate quantum spin ice on the pyrochlore lattice using semiclassical Monte Carlo and dynamical simulations of the effective ring exchange Hamiltonian. The model exhibits normal modes equivalent to photons as well as gapped vortices of the emergent magnetic field analogous to visons. Contrary to the behaviour of spinons in classical spin ice, we find that visons form a weak electrolyte; that is, their strong interaction makes the energy cost of a bound pair lower than that of an isolated vison. This leads to a qualitatively different temperature dependence of the pinch points in the corresponding emergent magnetic field. Finally, we observe that the thermal bath of photons dresses the visons and drastically reduces their energy. This suggests that visons may hybridise with the photon spectrum in quantum spin ice, which has potential implications on detecting them experimentally.