Details

Autor(en) / Beteiligte

• Kupriyanov, D
• Sokolov, I
• Havey, M
• Bidel, Y
• Chaneliere, T
• Delande, D
• Kaiser, R
• Labeyrie, G
• Miniatura, C
• Muller, C A
• Wilkowski, D
• Vaujour, E

Titel

Novel interference and dephasing effects in weak localization of light

Ist Teil von

• Bulletin of the American Physical Society, 2004-03, Vol.49 (1)

Erscheinungsjahr

2004

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Multiple light scattering creates mesoscopic coherences in optically dense ultracold atomic gases. Considerable interest has been generated by the possibility that at high densities strong localization, in which coherences collapse into localized subradiant excitations, may occur. At lower density, the main observable is the coherent backscattering (CBS) effect. In CBS, the intensity of resonance radiation scattered from the sample shows enhancement in the nearly backwards direction. We report remarkable effects that strongly modify the observed enhancement, and may have impact on studies of strong localization. First, theoretical results display destructive interference in CBS in atomic Rb, reducing the enhancement to less than unity. This surprising effect is due to quantum interference in light scattering, in the polarized effective medium, from nondegenerate hyperfine levels. Second, saturation experiments on the resonance transition in ultracold atomic Sr show that vacuum field fluctuations generate dephasing in multiple light scattering, and reduction in the CBS enhancement. Time-resolved studies show a drastic reduction of the diffusion coefficient and modification of CBS.