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arXiv · 2602.11637

First-order phase transition in atom-molecule quantum degenerate mixtures with coherent three-body recombination

Abstract

We map the phase diagram of a two-mode atom-molecule Bose-Einstein condensate with Fano-Feshbach and coherent three-body recombination (cTBR) terms. The standard second order phase transition observed as the molecular energy is tuned through the Feshbach resonance, is replaced by a first order transition when cTBR becomes prominent, due to a double-well structure in the free energy landscape. This transition is associated with atom-molecule entanglement, bistability, and molecular metastability. Our results establish cTBR as a powerful knob for quantum state engineering and control of reaction dynamics in ultracold chemistry.

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G. A. Bougas, A. Vardi, H. R. Sadeghpour, C. Chin, S. I. Mistakidis. 2026-02-12. First-order phase transition in atom-molecule quantum degenerate mixtures with coherent three-body recombination. https://doi.org/10.1103/llw4-tbnt

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