Nonlinear response of Kitaev spin model on square-octagon lattice*

Quantum computing promises to significantly accelerate research in materials discovery, characterization, and understanding. Simulations of correlated quantum spin systems and their dynamics are a primary application since such simulations are difficult on classical computers. Here, we focus on the computation of nonlinear correlation functions in frustrated quantum spin systems and perform a purely classical first benchmarking calculation in the Kitaev model on the square-octagon lattice. We show how the information contained in the nonlinear response functions allows distinguishing between different types of fractionalized excitations in the system, which we identify as a suitable target for future calculations of nonlinear response functions using quantum computers.