Dynamics of Rydberg spin waves in atomic ensembles
Abstract
We study the excitation, interaction and retrieval of collective excitations (spin waves) of Rydberg levels in large, optically thick atomic ensembles. Rather than assuming a Rydberg blockade mechanism, multiple Rydberg level excitations are allowed to mutually interact and dephase. We describe how dipole-dipole interactions destroy the correlations between spin waves leading to isolation and manipulation of individual excitations. Optical retrieval in a phase-matched direction shows the suppression of correlation. The dephasing process is suitable for the fast creation of high quality single photons with maximum efficiency 1/e. Individual excitations can be stored in separate weakly-interacting Rydberg levels and later entangled by applying a dedicated dephasing scheme. This mechanism is shown to have a favorable, approximately exponential, scaling. Strong dipole-dipole interactions required to speed up the protocol can be generated by mixing adjacent, opposite-parity Rydberg levels with a microwave field. This resonant coupling (ns + n'p ->n'p + ns) extends the 1/r^3 interaction over the whole ensemble, while short range Van der Waals channels (ns + ns ->np + (n-1)p) decay as 1/r^6.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- June 2012
- Bibcode:
- 2012APS..DMP.M6001B