Chemical Oscillation in Ultracold Chemistry

TL;DR

This paper reports the observation of chemical oscillations in ultracold atom-molecular Bose-Einstein condensates, revealing nonlinear dynamics, soliton solutions, and the influence of photoassociation and interactions on stability.

Contribution

It introduces the first demonstration of oscillatory reactions in ultracold chemistry with exact soliton solutions and analyzes the effects of photoassociation and interactions.

Findings

Oscillatory reactions occur in ultracold atom-molecular BECs.

Two types of in-phase bright localized gap solitons are identified.

Atomic density waves are observed in different interaction regimes.

Abstract

We demonstrate the occurrence of oscillatory reactions in the ultra-cold chemistry of atom-molecular Bose-Einstein condensate. Nonlinear oscillations in the mean-field dynamics occur for a specific range of elliptic modulus, giving rise to both in- and out-phase modulations in the atom-molecule population density. The reaction front velocity is found to be controlled by photoassociation, which also regulates the condensate density. Two distinct pair of in-phase bright localized gap solitons are found as exact solutions, existence of one of which necessarily requires a background. Cnoidal atomic density-waves in a plane wave molecular background are observed in both attractive and repulsive domains. Role of intra- and inter-species interactions on both existence and stability is explicated in the presence of photoassociation.