Signatures of fractionalized quasiparticle excitations in the dynamical spin-spin correlations of candidate quantum spin-liquid ground states

Numerical signatures of the fractionalized quasiparticle excitations (FQE) of quantum spin-liquid (QSL) ground states have recently been of interest given their experimental accessibility. Inelastic neutron scattering may reveal identifying characteristics of FQE in the dynamical structure factor [J. Knolle, et al. Phys. Rev. Lett. 112, 207203 (2014)], while measuring the heat capacity of candidate materials may show characteristic features of FQE’s via an analysis of a system’s entropy release [J. Nasu, et al. Phys. Rev. B. 92, 115122 (2015)]. Here, we introduce a new probe that unambiguously characterizes the FQE of QSL ground states. We theoretically study the spin dynamics of candidate QSL ground states, of various model Hamiltonians, on a variety of lattice geometries, and identify previously unknown signatures of their FQE’s. Numerical simulations carried out on finite sized clusters of the 2D Kitaev model on a honeycomb lattice reveal characteristic topological signatures of fractionalization in the time dependent spin-spin correlations, in an externally applied magnetic field. We discuss how experimental probes may detect this signature in candidate materials.