Intensity correlations and mesoscopic fluctuations of diffusing photons in cold atoms

Area of Science:

• Atomic physics
• Quantum optics
• Mesoscopic physics

Background:

• Photon scattering in disordered media typically follows Rayleigh law.
• Understanding speckle pattern correlations is crucial for characterizing wave propagation.
• Cold atomic clouds offer a unique system for studying light-matter interactions.

Purpose of the Study:

• To investigate the angular correlation function of speckle patterns from cold atomic clouds.
• To determine if atom-photon interactions lead to deviations from classical scattering predictions.
• To identify and describe novel mesoscopic effects in this system.

Main Methods:

• Analysis of the angular correlation function of scattered photons.
• Theoretical modeling of multiple photon scattering by cold atoms.
• Comparison with predictions for classical scatterers (Rayleigh law).

Main Results:

• The angular correlation function exceeds the Rayleigh law prediction for classical scatterers.
• Large intensity fluctuations are observed, indicating a new mesoscopic effect.
• This effect is specific to atom-photon interactions and not seen in systems like disordered metals.

Conclusions:

• Atom-photon interactions in cold atomic clouds produce a unique mesoscopic effect.
• The observed phenomenon deviates significantly from classical light scattering.
• The study provides a theoretical framework for experimental verification of these findings.