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Cavity-induced quantum droplets

Leon Mixa1,2,*, Milan Radonjić1,3, Axel Pelster4, and Michael Thorwart1,2,†

  • *Contact author: leon.mixa@uni-hamburg.de
  • †Contact author: michael.thorwart@uni-hamburg.de
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Phys. Rev. Research 7, 033216 – Published 3 September, 2025

DOI: https://doi.org/10.1103/68my-v17c

Abstract

Quantum droplets are formed in quantum many-body systems when the competition of quantum corrections with the mean-field interaction yields a stable self-bound quantum liquid. We predict the emergence of a quantum droplet when a Bose-Einstein condensate is placed in a transverse-pumped optical cavity. The strong coupling between the atoms and a cavity mode induces long-range interactions in the atoms, and a roton mode for negative cavity detuning emerges. Using Bogoliubov theory, we show that the roton mode competes with the repulsive atomic s-wave scattering. Due to the favorable scaling of the quantum fluctuations with respect to the volume, a self-bound stable quantum liquid emerges.

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Engineering quantum droplet formation by cavity-induced long-range interactions

Leon Mixa, Milan Radonjić, Axel Pelster, and Michael Thorwart
Phys. Rev. Research 7, 023204 (2025)

Article Text

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Outline

Information

Phys. Rev. Research 7, 033216– Published 3 September, 2025
  • Received 26 September 2024
  • Revised 31 January 2025
  • Accepted 21 July 2025
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