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Anomalous Oscillation Modes of Superfluid Pendant Droplets
Keita Onodera1, Ryuma Nagatomo1, Keito Miyake1
1Department of Applied Physics, <a href="https://ror.org/02e16g702">Hokkaido University</a>, Kita 13 Nishi 8, Kitaku, Sapporo, Hokkaido 060-8628, Japan.
Physical Review Letters
|December 6, 2024
Summary
Superfluid helium-4 droplets exhibit unique behaviors like horizontal translation and vertical oscillations. Their superfluidity enables anomalous droplet dynamics, including edge oscillations with weak size dependence.
Area of Science:
- Physics
- Fluid Dynamics
- Quantum Fluids
Background:
- Classical fluid droplets display limited dynamical phenomena on surfaces.
- Superfluidity in helium-4 (⁴He) offers unique fluid properties not found in classical fluids.
Purpose of the Study:
- To visualize and characterize the dynamical behaviors of superfluid ⁴He pendant droplets on a surface.
- To investigate anomalous modes of droplet motion and their dependence on droplet size.
Main Methods:
- High-resolution visualization techniques were employed to observe droplet dynamics.
- Experimental conditions were controlled to study droplet translation and oscillation.
Main Results:
- Superfluid ⁴He droplets demonstrated horizontal translation and corner bouncing (Noether mode), reflecting translation symmetry.
- Droplets exhibited high-amplitude vertical oscillations with edge movement, showing anomalously weak size dependence.
- The oscillation period remained constant despite changes in droplet size.
Conclusions:
- Superfluidity is crucial for the observed anomalous droplet dynamics, particularly the high mobility of droplet edges.
- The unique behaviors, such as the Noether mode and persistent oscillation periods, are direct consequences of superfluidity.
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