Scattering of microwave photons in superconducting transmission-line resonators coupled to charge qubits

Abstract

We investigate coherent single-microwave-photon transport in the coupled superconducting transmission lines coupled to superconducting quantum interference device based charge qubits. The Fano resonance can be observed in the scattering spectra in both the linear and nonlinear regimes of the dispersion relation of the microwave photon. We further find that the degree of the two-qubit entanglement can vary from unity to zero when the Fano resonance occurs. There exists a correspondence between the entanglement and the Fano resonance.