Merging of superfluid helium nanodroplets with vortices
| Autor: | Escartín, José María, Ancilotto, Francesco, Barranco, Manuel, Pi, Martí |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Escartín, José María [0000-0003-4940-2767], Pi, Martí [0000-0001-7706-262X], Apollo - University of Cambridge Repository |
| Rok vydání: | 2022 |
| Předmět: |
Vòrtexs
Condensed Matter - Mesoscale and Nanoscale Physics Superfluïdesa Quantum fluids and solids Fluid Dynamics (physics.flu-dyn) FOS: Physical sciences Physics - Fluid Dynamics Vortex-motion Helium 5103 Classical Physics Physics::Fluid Dynamics Vortices in superfluids Superfluidity Condensed Matter::Superconductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Heli Physics::Atomic and Molecular Clusters Density functional theory 51 Physical Sciences |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Dipòsit Digital de la UB Universidad de Barcelona Phys. Rev. B |
| Popis: | Within Density Functional Theory, we have investigated the coalescence dynamics of two superfluid helium nanodroplets hosting vortex lines in different relative orientations, which are drawn towards each other by the Van der Waals mutual attraction. We have found a rich phenomenology depending on how the vortex lines are oriented. In particular, when a vortex and anti-vortex lines are present in the merging droplets, a dark soliton develops at the droplet contact region, which eventually decays into vortex rings. Reconnection events are observed between the vortex lines or rings, leading to the creation of more vortices. Our simulations show the interplay between vortex creation and reconnections, as well as the effect of the droplet surface which pins the vortex ends and, by reflecting short-wavelength excitations produced by the interactions between vortices, strongly affects the droplet final state. Additional vorticity is nucleated in the proximity of surface indentations produced in the course of the dynamics, which in turn interact with other vortices present in the droplets. These effects, obviously absent in the case of bulk liquid helium, show that the droplet surface may act as a multiplier of vortex reconnections. The analysis of the energy spectrum shows that vortex-antivortex ring annihilation, as well as vortex-antivortex reconnections, yields roton bursts of different intensity. 11 pages, 11 figures + Supplemental Material |
| Databáze: | OpenAIRE |
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