# Non-monotonic diffusion rates in atom-optics L\'{e}vy kicked rotor

## TL;DR

This paper demonstrates experimentally that quantum diffusion in a Levy kicked atom-optics rotor exhibits non-monotonic behaviour as a function of Levy distribution parameters, revealing quantum effects absent in the classical limit.

## Contribution

It provides the first experimental evidence of non-monotonic quantum diffusion in a Levy kicked rotor and analytically identifies optimal diffusion parameters.

## Key findings

- Quantum diffusion shows non-monotonic dependence on Levy distribution parameters.
- Optimal diffusion rates are analytically derived and match experimental and numerical results.
- Non-monotonicity is a quantum effect that disappears in the classical limit.

## Abstract

The dynamics of chaotic Hamiltonian systems such as the kicked rotor continues to guide our understanding of transport and localization processes. The localized states of the quantum kicked rotor decay due to decoherence effects if subjected to stationary noise. The associated quantum diffusion increases monotonically as a function of a parameter characterising the noise distribution. In this work, for the Levy kicked atom-optics rotor, it is experimentally shown that by tuning a parameter characterizing the Levy distribution, quantum diffusion displays non-monotonic behaviour. The parameters for optimal diffusion rates are analytically obtained and they reveal a good agreement with the cold atom experiments and numerics. The non-monotonicity is shown to be a quantum effect that vanishes in the classical limit.