Chemical oscillation in ultracold chemistry

¹ Department of Physical Sciences, Indian Institute of Science Eduaction and Research Kolkata Kolkata, West Bengal 741246, India
² Department of Physics, University of Sheffield - Hounsfield Rd, Sheffield S3 7RH, UK
³ Department of Physics, Bankura Sammilani College - Kenduadihi, Bankura, West Bengal 722101, India
⁴ Department of Computer Science & Technology, University of Cambridge - 15 J.J. Thomson Ave., Cambridge CB3 0FD, UK

Received: 18 July 2023
Accepted: 2 February 2024

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 pairs of in-phase bright localized gap solitons are found as exact solutions, the existence of one of which necessarily requires a background. Cnoidal atomic density waves along with a plane-wave molecular motion are observed in both attractive and repulsive domains. The role of intra- and inter-species interactions on both existence and stability is explicated in the presence of photoassociation.