Physical Review A
Normal and abnormal nonlinear electromagnetically induced transparency due to dipole blockade of Rydberg excitation
Dong Yan, Cui-Li Cui, Yi-Mou Liu, Li-Jun Song, Jin‐Hui Wu
Abstract
We study the transmission properties of a probe field passing through a sample of $N$-type cold atoms possessing a high Rydberg state. Due to the conditioned dipole blockade of Rydberg excitation, this atomic sample might exhibit a nonlinear optical response in terms of electromagnetically induced transparency (EIT) as manifested by the sensitivity of the transmitted probe intensity and correlation to input probe intensity and correlation. It is of particular interest that the nonlinear EIT response can be opposite (either normal or abnormal) in two different regions of probe detuning, which is a striking feature of the four-level N system of interacting atoms. The realization of both normal and abnormal nonlinear EIT effects in one atomic sample is expected to have wider applications in manipulation of photonic statistics of weak light signals, e.g., to attain prominent photonic bunching and/or antibunching in a dynamic quantum delay or memory process.