At a Glance
- Researchers from the National Institute of Optics, the University of Florence, and LENS observed capillary instability in ultra-cold quantum gases, offering new insights into their behavior under certain conditions.
- The study involved a mixture of potassium and rubidium atoms cooled to near absolute zero and released in an optical waveguide. The gases exhibited behavior similar to classical liquids, such as droplet formation.
- The splitting of quantum droplets into smaller droplets was explained by capillary instability, driven by surface tension, a phenomenon previously observed in liquids like raindrops and soap bubbles.
- The researchers used experimental measurements and numerical simulations to show that quantum droplet breakup follows the Plateau-Rayleigh instability observed in classical liquids and superfluid helium.
- This discovery of quantum droplet behavior could have major implications for quantum technologies. It could aid the development of new quantum materials by improving our understanding of quantum gas properties.
A team of researchers from the National Institute of Optics, the University of Florence, and the European Laboratory for Non-linear Spectroscopy (LENS) has recently observed a fascinating phenomenon in quantum gases—capillary instability. The research, published in Physical Review Letters, provides new insights into the behavior of ultra-cold gases, which can act like liquids under certain conditions.
In their study, the scientists worked with a mixture of potassium (41K) and rubidium (87Rb) atoms, cooled to temperatures close to absolute zero. These ultra-cold gases behave according to quantum mechanics and were released in an optical waveguide. The team manipulated the interatomic interactions, creating a quantum droplet, which initially formed as a single droplet but later split into smaller droplets, resembling the behavior of classical liquids like raindrops or soap bubbles.
This splitting behavior was explained through capillary instability, a process driven by surface tension. Surface tension occurs when molecules in a liquid pull together to minimize surface area, leading to phenomena like the breakup of a thin liquid jet into droplets. The researchers discovered that this same principle applies to quantum droplets, a finding that had not been observed before in atomic gases.
The researchers combined experimental measurements and numerical simulations to show how the breakup of quantum droplets aligns with the Plateau-Rayleigh instability, which has been observed in classical liquids and superfluid helium. This breakthrough could have significant implications for the development of quantum technologies, as understanding the properties of quantum droplets may help scientists create new types of quantum materials.
References
- CNR-INO. (2025, April 10). Scientists observe the first ‘quantum rain’. Phys.Org; CNR-INO. https://phys.org/news/2025-04-scientists-quantum.html
- Cavicchioli, L., Fort, C., Ancilotto, F., Modugno, M., Minardi, F., & Burchianti, A. (2025). Dynamical formation of multiple quantum droplets in a bose-bose mixture. Physical Review Letters, 134(9), 093401. https://doi.org/10.1103/PhysRevLett.134.093401
