Electro-optic control of atom-light interactions using Rydberg dark-state polaritons

Abstract

We demonstrate a multiphoton Rydberg dark resonance where a Λ system is coupled to a Rydberg state. This N -type level scheme combines the ability to slow and store light pulses associated with long-lived ground-state superpositions with the strongly interacting character of Rydberg states. For the n d5/2 Rydberg state in R 87 b (with n=26 or 44) and a beam size of 1 mm, we observe a resonance linewidth of less than 100 kHz in a room-temperature atomic ensemble limited by transit-time broadening. The resonance is switchable with an electric field of order 1 V cm-1. Applications in electro-optic switching and photonic phase gates are discussed. © 2008 The American Physical Society.