Damping of Vacuum Rabi Oscillations in a Two-Qubit Structure in a High-Q Cavity

The article studies the attenuation of vacuum Rabi oscillations for a system of two superconducting solid-state qubits placed in a high-Q microwave cavity. Two different cases are considered in which: 1) the first qubit is excited at the initial time and 2) the initial state comprises an entangled symmetric and antisymmetric pair of states. The dependence of the attenuation on various parameters, primarily on the coupling constant between qubits and the field and on the distance between qubits, is studied in detail. It is shown that, for some parameters, the relaxation time of the excited state of a qubit in such a system is significantly longer than that of a single qubit in the cavity.