Generalized dark-state polaritons for photon memory in multilevel atomic media

Abstract

We generalize the concept of dark-state polariton in multilevel electromagnetically induced transparency systems. We show that the quantum states of light for the pulses can be mapped onto more than one collective atomic polarization states of the multilevel atomic system, which can act as a quantum state copier or divider. Such dark-state polaritons potentially have applications in quantum information processing.