Diffusion induced decoherence of stored optical vortices

Abstract

We study the coherence properties of optical vortices stored in atomic ensembles. In the presence of thermal diffusion, the topological nature of stored optical vortices is found not to guarantee slow decoherence. Instead the stored vortex state has decoherence surprisingly larger than the stored Gaussian mode. Generally, the less phase gradient, the more robust for stored coherence against diffusion. Furthermore, calculation of coherence factor shows that the center of stored vortex becomes completely incoherent once diffusion begins and, when reading laser is applied, the optical intensity at the center of the vortex becomes nonzero. Its implication for quantum information is discussed. Comparison of classical diffusion and quantum diffusion is also presented.

5 pages, 2 figures

References in corpus (4)

• Quantized Rotation of Atoms From Photons with Orbital Angular Momentum
• The Vortex Phase Qubit: Generating Arbitrary, Counter-Rotating, Coherent Superpositions in Bose-Einstein Condensates via Optical Angular Momentum Beams
• A fast and robust approach to long-distance quantum communication with atomic ensembles
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Cited by in corpus (2)

• Storing images in warm atomic vapor
• Image Storage in Hot Vapors