Journal of Physics B Atomic Molecular and Optical Physics
Einstein–Podolsky–Rosen entanglement via nonlinear processes enhanced by electromagnetically induced transparency
Guangling Cheng, Xiangming Hu, Wenxue Zhong
Abstract
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.