Tunable Anomalous Diffusion in Subrecoil-Laser-Cooled Atoms

Area of Science:

• Atomic physics
• Quantum information science
• Nonlinear dynamics

Background:

• Laser cooling of atomic motion is fundamental for quantum information and precision metrology.
• The spatial spreading of subrecoil-laser-cooled atoms is critical for understanding cooling and confinement but remains understudied.
• Anomalous diffusion describes particle transport deviating from classical Brownian motion.

Purpose of the Study:

• To analyze anomalous diffusion in subrecoil-laser-cooled atoms.
• To investigate the influence of velocity-dependent fluorescence rates on atomic transport.
• To identify conditions for optimal atomic confinement and explore connections to nonlinear dynamics.

Main Methods:

• Analysis of anomalous diffusion in subrecoil-laser-cooled atoms.
• Modeling transport properties governed by a velocity-dependent fluorescence rate R(v) proportional to |v|^α.
• Investigating transitions between normal, subdiffusive, and superdiffusive regimes by tuning the exponent α.

Main Results:

• Discovered transitions between normal, subdiffusive, and superdiffusive regimes by tuning the exponent α.
• Identified that diffusion is minimized at α=3/2, leading to optimal atomic confinement.
• Established a conceptual link between subrecoil laser cooling and the Pomeau-Manneville map.

Conclusions:

• Anomalous diffusion in laser-cooled atoms exhibits tunable transport properties based on fluorescence rate.
• Optimal atomic confinement is achieved at a specific parameter (α=3/2), minimizing spatial spreading.
• The study reveals a generic principle of non-trivial minima in spatial spreading applicable across diverse physical systems, including nonlinear dynamics.