Many-body Chemical Reactions in a Quantum Degenerate Gas

TL;DR

This paper demonstrates the observation of collective quantum chemical reactions in a Bose-Einstein condensate, revealing bosonic enhancement and coherent dynamics, and introduces a quantum field model for these many-body processes.

Contribution

It reports the first observation of super-chemistry involving coherent, collective reactions between atoms and molecules near a Feshbach resonance, advancing quantum many-body chemistry understanding.

Findings

Observation of rapid molecular formation from atomic condensates

Detection of population oscillations indicating coherence

Identification of three-body recombination as the main process

Abstract

Chemical reactions in the quantum degenerate regime are described by mixing of matterwave fields. Quantum coherence and bosonic enhancement are two unique features of many-body reactions involving bosonic reactants and products. Such collective reactions of chemicals, dubbed "super-chemistry", is an elusive goal in quantum chemistry research. Here we report the observation of coherent and collective reactive coupling between Bose condensed atoms and molecules near a Feshbach resonance. Starting from an atomic condensate, the reaction begins with a rapid formation of molecules, followed by oscillations of their populations in the equilibration process. Faster oscillations are observed in samples with higher densities, indicating bosonic enhancement. We present a quantum field model which describes the dynamics well and identifies three-body recombination as the dominant reaction process. Our findings exemplify the highly sought-after quantum many-body chemistry and offer a new paradigm for the control of quantum chemical reactions.