Collective Radiative Dynamics of an Ensemble of Cold Atoms Coupled to an Optical Waveguide

Area of Science:

• Quantum optics
• Atomic physics
• Nanophotonics

Background:

• Collective radiative effects are crucial in quantum optics.
• Optical nanofibers provide a unique platform for controlling light-matter interactions.
• Understanding superradiance is key to developing quantum technologies.

Purpose of the Study:

• To experimentally and theoretically investigate collective radiative effects in cold atoms coupled to an optical nanofiber.
• To analyze the microscopic dynamics of light-matter interactions in this system.
• To explore the directional properties of superradiant decay.

Main Methods:

• Coupling an ensemble of cold atoms to a single-mode optical nanofiber.
• Using time-resolved measurements of transmitted and reflected light.
• Employing position-resolved measurements within a fiber ring resonator.

Main Results:

• Observed superradiant decay rates over 1 order of magnitude faster than single-atom decay in the forward direction.
• Demonstrated no decay rate speed-up in the backward direction.
• Revealed the progressive growth of the collective atomic response along the array.

Conclusions:

• Collective interactions lead to directional superradiance in cold atom-nanofiber systems.
• Nanophotonic cold atom systems offer unique opportunities for studying light-matter interactions.
• The findings pave the way for novel quantum optical devices.