Tunable disorder in a crystal of cold polar molecules

TL;DR

This paper demonstrates how external electric fields can control exciton dynamics and impurity interactions in a cold polar molecule crystal, enabling quantum simulation of disorder effects.

Contribution

It introduces a method to tune disorder and exciton interactions in ultracold polar molecules on an optical lattice using external fields.

Findings

Controlled exciton-impurity interactions via electric fields.

Formation of a phononless crystal with tunable disorder.

Potential for quantum simulation of localization phenomena.

Abstract

In the present work, we demonstrate the possibility of controlling by an external field the dynamics of collective excitations (excitons) of molecules on an optical lattice. We show that a suitably chosen two-species mixture of ultracold polar molecules loaded on an optical lattice forms a phononless crystal, where exciton-impurity interactions can be controlled by applying an external electric field. This can be used for the controlled creation of many-body entangled states of ultracold molecules and the time-domain quantum simulation of disorder-induced localization and delocalization of quantum particles.