Nonlinear response of the Kitaev honeycomb lattice model in a weak magnetic field

We investigate the nonlinear response of Kitaev honeycomb lattice model in a weak magnetic field using theory two-dimensional (2D) coherent spectroscopy. observe that at isotropic point non-Abelian phase this model, spectrum 2D frequency domain consists sharp signals originate from flux excitations and Majorana bound states. Signatures different can be clearly observed spectrum, such one evidences states with 4-adjacent, 2-nonadjacent, 4-far-separated fluxes, which are not visible linear spectroscopy as neutron scattering experiments. Moreover, Abelian we perceive is composed streak signals. These signals, pure represent distinct signature itinerant fermions. However, deep whenever exchange coupling much stronger than others, weakened only single spots seen response, resembles dispersionless conventional toric code.