In situ tunable nonlinearity and competing signal paths in coupled superconducting resonators

We study superconducting quantum circuits consisting of two coupled nonlinear resonators that are suitable for quantum simulation of Bose-Hubbard systems and perform a classical simulation of the Bose-Hubbard model for a two-site lattice. By measuring the microwave transmission as a function of the applied magnetic flux and microwave power, we extract the nonlinearity of the resonators by comparing the experimental data with a circuit model that includes a parasitic path.