Karpov D. Features of the electrodynamics of the mesoscopic system of superconducting quantum bits interacting with a resonator

The thesis is devoted to a theoretical study of the features of the interaction of two-level systems – quantum bits – with the electromagnetic field of a resonator in cases of a classical and quantum signal. Explicit expressions are found for the coefficient of transmission of an electromagnetic signal through the qubit resonator system in the case of a dual-mode resonator. It is shown that in the case of the interaction of a qubit with two signals, the output signal can be amplified or weakened. It is established that the qubit acts as a quantum nonlinear object. The problem of passing single-photon signals through a waveguide connected with a qubit-resonator system have been solved. An original approach to solving problems of passing a single photon through a waveguide based on the method of a non-hermitescher Hamiltonian and a scattering matrix is proposed. It has been established that in the system there are possible resonances with an asymmetric profile, which depend on the frequency of the input photon.