Observation of coherent oscillations in association of dimers from a thermal gas of ultracold atoms

TL;DR

This paper reports the observation of coherent oscillations in the formation of weakly-bound dimers from ultracold atoms, demonstrating control over coherence loss and revival through modulation techniques.

Contribution

It introduces a method to restore and control coherence in atom-dimer conversion processes using non-adiabatic modulation of molecular energy levels.

Findings

Coherent oscillations observed in dimer formation efficiency.

Coherence can be restored via strong modulation pulses.

Theoretical models support experimental results.

Abstract

We report the observation of coherent oscillations in conversion efficiency of weakly-bound dimers formed from a thermal gas of ultracold atoms. Finite thermal energy of the gas causes loss of coherence when a broad continuum is resonantly coupled to a discrete bound state. Restoration of the coherence can be achieved through non-adiabatic transitions of the dressed molecular energy level that are induced by a strong modulation pulse with fast envelope dynamics. Conditions to observe coherent oscillations are verified, and control of their properties is demonstrated. The main experimental findings are supported by theoretical modeling and numerical calculations. The observed results may lead to a renewed interest in general studies of a discrete energy level coupled to a broadband continuum when the properties of both are fully controlled.