Experimental investigation of early-time diffusion in the quantum kicked rotor using a Bose-Einstein condensate

TL;DR

This paper experimentally studies early-time diffusion in the quantum kicked rotor using a Bose-Einstein condensate, revealing resonances and anti-resonances in momentum diffusion rates and comparing results with theory.

Contribution

It provides the first experimental observation of early-time resonances in the quantum kicked rotor with ultra-cold atoms, highlighting quantum effects in momentum diffusion.

Findings

Observation of quantum resonances in momentum diffusion rates

Detection of anti-resonances where the system returns to initial state

Comparison of experimental results with theoretical predictions

Abstract

We report the experimental observation of resonances in the early-time momentum diffusion rates for the atom-optical delta-kicked rotor. In this work a Bose-Einstein condensate provides a source of ultra-cold atoms with an ultra-narow initial momentum distribution, which is then subjected to periodic pulses (or "kicks") using an intense far-detuned optical standing wave. A quantum resonance occurs when the momentum eigenstates accumulate the same phase between kicks leading to ballistic energy growth. Conversely, an anti-resonance is observed when the phase accumulated from successive kicks cancels and the system returns to its initial state. Our experimental results are compared with theoretical predictions.