Optimal control of complex atomic quantum systems

TL;DR

This paper demonstrates the application of optimal control theory to complex atomic quantum systems, specifically Bose-Einstein condensates and quantum phase transitions, achieving fast, robust manipulation with experimental validation.

Contribution

It provides the first experimental implementation of optimal control on many-body quantum dynamics in cold atom systems, enhancing control precision and robustness.

Findings

Optimal control enables fast, robust manipulation of atomic quantum states.

Experimental results align well with theoretical predictions.

Control protocols are resilient to temperature and atom number fluctuations.

Abstract

Quantum technologies will ultimately require manipulating many-body quantum systems with high precision. Cold atom experiments represent a stepping stone in that direction: a high degree of control has been achieved on systems of increasing complexity, however, this control is still sub-optimal. Optimal control theory is the ideal candidate to bridge the gap between early stage and optimal experimental protocols, particularly since it was extended to encompass many-body quantum dynamics. Here, we experimentally demonstrate optimal control applied to two dynamical processes subject to interactions: the coherent manipulation of motional states of an atomic Bose-Einstein condensate and the crossing of a quantum phase transition in small systems of cold atoms in optical lattices. We show theoretically that these transformations can be made fast and robust with respect to perturbations, including temperature and atom number fluctuations, resulting in a good agreement between theoretical predictions and experimental results.