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. 
Guozhu Sun, Zhongyuan Zhou, Bo Mao, Xueda Wen, Peiheng Wu and Siyuan   Han
cond-mat.mes-hall quant-ph