Dynamics of fractionalization in quantum spin liquids

Quantum spin liquids are elusive states of matter, which have been predicted more than four decades ago but have not so far been conclusively sighted in nature. In this paper the authors study the so called `extended Kitaev model', which has a number of different quantum spin-liquid phases including one with non-Abelian excitations. They present a solution of a long standing problem for this model, namely, the problem of obtaining the dynamical response function. Using a rarely available exact calculation, they find that there are indeed clear signatures in the spin structure factor betraying the presence of spin-liquids and their fractionalized quasi-particles, including those with non-Abelian statistics.