Einstein–Podolsky–Rosen entanglement via nonlinear processes enhanced by electromagnetically induced transparency
Guangling Cheng, Xiangming Hu, Wenxue Zhong · Journal of Physics B Atomic Molecular and Optical Physics · 2009
We show that Einstein–Podolsky–Rosen (EPR) light entanglement is obtainable via the resonant nonlinear interactions enhanced by electromagnetically induced transparency. A three-level system is used as a unified model, where two metastable states are coupled to each other via microwave, or Raman, or two-photon transition, and the upper metastable state is coupled to the excited state. A pair of inner sidebands is amplified as optical cavity modes via the transition from the excited state to the other metastable state. The analysis is presented by using the dressed-atom squeezed-transformed-mode approach. For a proper ratio of the amplitudes of the applied fields, the sum of the variances for two EPR-like operators approaches zero, which corresponds to EPR entanglement.