- Open Access
Marginally volume-dependent oscillation modes of superfluid pendant droplets in an intervening stability region
Phys. Rev. Research 8, 033255 – Published 1 September, 2026
DOI: https://doi.org/10.1103/qjzn-l6yj
Abstract
Droplets are ubiquitous in nature and industry, yet their behavior is not yet fully understood, particularly for extreme conditions not typically encountered in viscous classical fluids. In this study, we investigated the oscillations of a superfluid pendant droplet formed beneath a cup by superfluid film flow. We controlled the mobility of the droplet's edge by attaching cylinders of varying diameter to the underside of the cup, so that the droplet was suspended from the bottom of the cylinder. For wide cylinders or in the absence of a cylinder, the lowest point of the droplet oscillated vertically, while the edge oscillated along the surface, with only a slight dependence of the oscillation period on the droplet volume, which contradicts the common assumption in classical fluids that larger droplets oscillate with a longer period. For narrow cylinders, the droplet oscillated vertically, while the edge remained fixed at the cylinder's edge, and the oscillation period increased monotonically with increasing droplet volume, displaying the expected behavior. These observations demonstrate that free motion of the droplet's edge contributes to anomalous volume-independent oscillation of pendant droplets. We propose that the marginal volume dependence arises from the stability of superfluid pendant droplets in a region between two instabilities. This behavior is significant only for fluids that completely wet the substrate and possess a mobile edge, a condition rarely observed in classical fluids but naturally occurring in superfluids. Hence, these findings reveal unique properties of droplets in superfluid not seen in classical fluids.
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References (38)
- J. Wilks, The Properties of Liquid and Solid Helium (Oxford University Press, New York, 1967).
- D. R. Tilley and J. Tilley, Superfluidity and Superconductivity (Institute of Physics Publishing, Bristol, UK, 1990).
- J. G. Daunt and K. Mendelssohn, Transfer of helium II on glass, Nature (London) 141, 911 (1938).
- J. Usami, N. Kato, T. Matsui, and H. Fukuyama, The role of substrate roughness in superfluid film flow velocity, J. Low Temp. Phys. 196, 52 (2019).
- K. Onodera, R. Nagatomo, S. Kashimoto, and R. Nomura, A Simple way to enhance the film flow of superfluid by coating, J. Phys. Soc. Jpn. 91, 065005 (2022).
- J. C. Burton, J. E. Rutledge, and P. Taborek, Fluid pinch-off in superfluid and normal , Phys. Rev. E 75, 036311 (2007).
- N. B. Speirs, K. R. Langley, P. Taborek, and S. T. Thoroddsen, Jet breakup in superfluid and normal liquid , Phys. Rev. Fluids 5, 044001 (2020).
- M. A. Weilert, D. L. Whitaker, H. J. Maris, and G. M. Seidel, Magnetic levitation and noncoalescence of liquid helium, Phys. Rev. Lett. 77, 4840 (1996).
- D. L. Whitaker, C. Kim, C. L. Vicente, M. A. Weilert, H. J. Maris, and G. M. Seidel, Shape oscillations in levitated He II drops, J. Low Temp. Phys. 113, 491 (1998).
- C. Vicente, W. Yao, H. J. Maris, and G. M. Seidel, Surface tension of liquid as measured using the vibration modes of a levitated drop, Phys. Rev. B 66, 214504 (2002).
- J. P. Toennies and A. F. Vilesov, Superfluid helium droplets: A uniquely cold nanomatrix for molecules and molecular complexes, Angew. Chem. Int. Ed. 43, 2622 (2004).
- L. F. Gomez et al., Shapes and vorticities of superfluid helium nanodroplets, Science 345, 906 (2014).
- C. G. Baker, G. I. Harris, D. L. McAuslan, Y. Sachkou, X. He, and W. P. Bowen, Theoretical framework for thin film superfluid optomechanics: Towards the quantum regime, New J. Phys. 18, 123025 (2016).
- D. L. McAuslan, G. I. Harris, C. Baker, Y. Sachkou, X. He, E. Sheridan, and W. P. Bowen, Microphotonic forces from superfluid flow, Phys. Rev. X 6, 021012 (2016).
- L. Childress, M. P. Schmidt, A. D. Kashkanova, C. D. Brown, G. I. Harris, A. Aiello, F. Marquardt, and J. G. E. Harris, Cavity optomechanics in a levitated helium drop, Phys. Rev. A 96, 063842 (2017).
- C. D. Brown, Y. Wang, M. Namazi, G. I. Harris, M. T. Uysal, and J. G. E. Harris, Superfluid helium drops levitated in high vacuum, Phys. Rev. Lett. 130, 216001 (2023).
- L. Rayleigh, On the capillary phenomena of jets, Proc. R. Soc. London 29, 71 (1879).
- L. D. Landau and E. M. Lifshitz, Fluid Mechanics (Butterwoth-Heinemann, Oxford, 1981).
- J. Austin, A mechanical treatment of the leaky faucet experiment, Phys. Lett. A 155, 148 (1991).
- J. McCraney, V. Kern, J. B. Bostwick, S. Daniel, and P. H. Steen, Oscillations of drops with mobile contact lines on the international space station: Elucidation of terrestrial inertial droplet spreading, Phys. Rev. Lett. 129, 084501 (2022).
- P. H. Steen, C. Chang, and J. B. Bostwick, Droplet motions fill a periodic table, Proc. Natl. Acad. Sci. USA 116, 4849 (2019).
- J. B. Bostwick and P. H. Steen, Dynamics of sessile drops. Part 1. Inviscid theory, J. Fluid Mech. 760, 5 (2014).
- F. Zhang, X. Zhou, and H. Ding, Effects of gravity on natural oscillations of sessile drops, J. Fluid Mech. 962, A10 (2023).
- R. Nagatomo, K. Onodera, S. Kashimoto, Y. Aoki, and R. Nomura, Robust quantization of dripping periods of superfluid , J. Phys. Soc. Jpn. 92, 124601 (2023).
- K. Onodera, R. Nagatomo, K. Miyake, R. Yamane, S. Takamatsu, Y. Aoki, and R. Nomura, Anomalous oscillation modes of superfluid pendant droplets, Phys. Rev. Lett. 133, 216001 (2024).
- T. Tani, K. Sawada, K. Miyake, S. Takamatsu, R. Yamane, Y. Ishimoto, R. Matsukawa, Y. Aoki, and R. Nomura, Lack of oscillatory motion of superfluid during its dripping from a needle, J. Phys. Soc. Jpn. 94, 065001 (2025).
- See Supplemental Material at http://link.aps.org/supplemental/10.1103/qjzn-l6yj for the movie file.
- F. Zhang and X. Zhou, Static and dynamic stability of pendant drops, J. Fluid Mech. 968, A30 (2023).
- F. Gallaire and P. T. Brun, Fluid dynamic instabilities: Theory and application to pattern forming in complex media, Philos. Trans. R. Soc. A375, 20160155 (2017).
- P. G. de Gennes, F. Brochard-Wyart, and D. Quéré, Capillarity and Wetting Phenomena: Drops, Bubbles, Pearls, Waves (Springer, New York, 2004).
- A. J. Allen and P. A. Hughes, The Rayleigh–Taylor instability in astrophysical fluids, Mon. Not. R. Astron. Soc. 208, 609 (1984).
- P. Tremblin, H. Bloch, M. González, E. Audit, S. Fromang, T. Padioleau, P. Kestener, and S. Kokh, Radiative rayleigh-taylor instability and the structure of clouds in planetary atmospheres, Astron. Astrophys. 653, A30 (2021).
- K. Sasaki, N. Suzuki, D. Akamatsu, and H. Saito, Rayleigh-Taylor instability and mushroom-pattern formation in a two-component Bose-Einstein condensate, Phys. Rev. A 80, 063611 (2009).
- R. Shaw, The Dripping Faucet as a Model Chaotic System (Aerial Press, Santa Cruz, 1984).
- P. Martien, S. C. Pope, P. L. Scott, and R. S. Shaw, The chaotic behavior of the leaky faucet, Phys. Lett. A 110, 399 (1985).
- K. Kiyono and N. Fuchikami, Dripping faucet dynamics by an improved mass-spring model, J. Phys. Soc. Jpn. 68, 3259 (1999).
- K. Kiyono and N. Fuchikami, Bifurcations induced by periodic forcing and taming chaos in dripping faucets, J. Phys. Soc. Jpn. 71, 49 (2002).
- S. Takamatsu, R. Yamane, T. Tani, Y. Ishimoto, K. Miyake, Y. Aoki, and R. Nomura, Superfluid dripping: A new analog for continuous time crystals, New J. Phys. 27, 123503 (2025).