MIXED-STATE ENTANGLEMENT IN A SINGLE-COOPER-PAIR BOX DETUNED WITH A COHERENT FIELD
Zhaoxin Li, Yan Xu, LUYIN ZHANG, Da Chen · International Journal of Modern Physics B · 2011
A system composed of a single-Cooper-pair box irradiated by a single-mode quantized field has been considered. The entanglement relative to the mixedness μ and the detuning δ is investigated with negative partial transpose. It is found that in the case of initial mixed state, the entanglement is weakened, but increases as time evolves. For a detuned system, the entanglement is further suppressed but more stationary than that for a resonant system.