L\'evy flights of photons in hot atomic vapours

TL;DR

This paper experimentally demonstrates that photons undergoing diffusion in hot atomic vapours exhibit Le9vy flight behavior, characterized by a power-law step size distribution, highlighting non-Gaussian anomalous diffusion.

Contribution

The study provides the first direct measurement of Le9vy flight step size distribution for photons in hot atomic vapours, confirming non-Gaussian anomalous diffusion.

Findings

Photon step size distribution follows a power law.

Photon diffusion exhibits Le9vy flight characteristics.

Experimental evidence of non-Gaussian anomalous diffusion.

Abstract

Properties of random and fluctuating systems are often studied through the use of Gaussian distributions. However, in a number of situations, rare events have drastic consequences, which can not be explained by Gaussian statistics. Considerable efforts have thus been devoted to the study of non Gaussian fluctuations such as L\'evy statistics, generalizing the standard description of random walks. Unfortunately only macroscopic signatures, obtained by averaging over many random steps, are usually observed in physical systems. We present experimental results investigating the elementary process of anomalous diffusion of photons in hot atomic vapours. We measure the step size distribution of the random walk and show that it follows a power law characteristic of L\'evy flights.