QUANTIFICATION OF MIXED-STATE ENTANGLEMENT IN A QUANTUM SYSTEM INTERACTING WITH TWO TIME-DEPENDENT LASERS

摘要

We give a theoretical description of two time-dependent laser beams in the A scheme using a unitary transformation method and a trapped three-level ion. We extend earlier investigations aimed at finding the three types of density matrices. We present figures showing that the entanglement degree accelerates due to the time-dependent interaction and the second-order terms of the Lamb-Dicke parameter η(t). Our results explain that the time-dependent ionic-phononic quantum system is observed at a higher degree of entanglement for three optimum times; these are, respectively, 16.5, 110, and 220 fs. These optimum entangled states can be modified for the structure of black holes in a probabilistic Universe.