Dynamically Probing Ultracold Lattice Gases via Rydberg Molecules

TL;DR

This paper introduces a method using Rydberg molecules to dynamically and precisely probe the site occupancy and phase transitions in ultracold lattice gases, enabling real-time diagnostics.

Contribution

It demonstrates a novel technique for real-time, site-specific probing of ultracold lattice gases using Rydberg molecules and ion detection.

Findings

Superfluid gases show widespread molecule formation.

Mott insulators with n=1 show suppressed molecule formation.

Technique can monitor superfluid to Mott insulator transition in real-time.

Abstract

We show that the excitation of long-range Rydberg molecules in a three-dimensional optical lattice can be used as a position- and time-sensitive probe of the site occupancy in the system. To this end, we detect the ions which are continuously generated by the decay of the formed Rydberg molecules. While a superfluid gas shows molecule formation for all parameters, a Mott insulator with $n=1$ filling reveals a strong suppression of the number of formed molecules. In the limit of weak probing, the technique can be used to probe the superfluid to Mott-insulator transition in real-time. Our method can be extended to higher fillings and has various applications for the real-time diagnosis and manipulation of ultracold lattice gases.