Entanglement dynamics of a superconducting phase qubit coupled to a two-level system
We report the observation and quantitative characterization of driven and
spontaneous oscillations of quantum entanglement, as measured by concurrence,
in a bipartite system consisting of a macroscopic Josephson phase qubit coupled
to a microscopic two-level system. The data clearly show the behavior of
entanglement dynamics such as sudden death and revival, and the effect of
decoherence and ac driving on entanglement.