Two-photon coupling via Josephson element II: Interaction dressing, cross-Kerr coupling, and limits of low-energy bosonic model
This paper investigates the renormalization of interactions mediated by a symmetric SQUID in a coupled phase qubit system, demonstrating that cross-Kerr coupling persists due to potential asymmetry and coupler nonlinearity, while establishing the limits of the low-energy bosonic model and providing verifiable predictions for two-photon detection and quantum-nondemolition readout applications.