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  • Letter
  • Open Access

Unveiling the Bose-Einstein condensate-droplet crossover with Rayleigh superradiant scattering

Mithilesh K. Parit1,*, Mingchen Huang1,*, Ziting Chen1, Yifei He1, Haoting Zhen1,2, and Gyu-Boong Jo1,2,3,4,†

  • *These authors contributed equally to this work.
  • †Contact author: gbjo@rice.edu
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Phys. Rev. Research 8, L042012 – Published 28 October, 2026

DOI: https://doi.org/10.1103/j662-tz3j

Abstract

Light scattering plays an essential role in uncovering the properties of quantum states through light-matter interactions. Here, we explore the crossover from Bose-Einstein condensate (BEC) to droplets in a dipolar Er166 gas by employing superradiant light scattering as both a probing and controlling tool. We observe that the efficiency of superradiant scattering exhibits a nonmonotonic behavior akin to the rate of sample expansion during the transition, signaling its sensitivity to the initial quantum state, and in turn revealing the BEC-droplet crossover. Through controlled atom depletion via superradiance, we analyze the sample's expansion dynamics and aspect ratio to identify the BEC-droplet phases distinctly, supported by Gaussian variational ansatz calculations. Finally, using these two approaches, we track how the BEC-droplet crossover points shift under varying magnetic field orientations. Our results show that superradiance can provide a state-sensitive probe and implement rapid atom-number quenches, opening new avenues for studying quantum states in atomic matter.

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Phys. Rev. Research 8, L042012– Published 28 October, 2026
  • Received 28 April 2025
  • Accepted 10 October 2026
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