Non-exponential decoherence and subdiffusion in atom-optics kicked rotor

TL;DR

This paper demonstrates experimentally that non-stationary Lévy noise induces slower-than-exponential decoherence and quantum subdiffusion in an atom-optics kicked rotor, with results aligning with analytical and numerical models.

Contribution

It introduces a method to control quantum coherence decay and subdiffusion using Lévy noise in atom-optics systems, revealing new dynamics beyond exponential decoherence.

Findings

Slower-than-exponential coherence decay observed

Quantum subdiffusion controlled by Lévy exponent

Experimental results match analytical and numerical predictions

Abstract

Quantum systems lose coherence upon interaction with the environment and tend towards classical states. Quantum coherence is known to exponentially decay in time so that macroscopic quantum superpositions are generally unsustainable. In this work, slower than exponential decay of coherences is experimentally realized in an atom-optics kicked rotor system subjected to non-stationary L\'{e}vy noise in the applied kick sequence. The slower coherence decay manifests in the form of quantum subdiffusion that can be controlled through the L\'{e}vy exponent. The experimental results are in good agreement with the analytical estimates and numerical simulations for the mean energy growth and momentum profiles of atom-optics kicked rotor.