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12:11
Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Local superfluidity of parahydrogen clusters.
Fabio Mezzacapo1, Massimo Boninsegni
1Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2G7.
Physical Review Letters
|June 4, 2008
Summary
Quantum Monte Carlo simulations reveal that small parahydrogen clusters exhibit uniform superfluidity, not just at the surface. This occurs due to long molecular exchange cycles, challenging previous surface-only superfluidity claims.
Area of Science:
- Quantum physics
- Low-temperature condensed matter physics
- Molecular clusters
Background:
- Superfluidity in small parahydrogen clusters has been a subject of recent debate.
- Previous studies suggested superfluidity might be confined to the surface of these clusters.
Purpose of the Study:
- To investigate the local superfluid response of small parahydrogen clusters.
- To determine the spatial distribution of superfluidity within these clusters at low temperatures.
Main Methods:
- Utilizing quantum Monte Carlo simulations.
- Analyzing parahydrogen clusters with up to 27 molecules.
- Simulating temperatures as low as 0.05 K.
Main Results:
- Superfluidity is not limited to the surface of parahydrogen clusters.
- Even clusters with distinct shell structures display uniform superfluidity.
- Superfluidity arises from extended exchange cycles involving all molecules.
Conclusions:
- The findings contradict recent claims of surface-confined superfluidity.
- Small parahydrogen clusters are uniformly superfluid at low temperatures.
- Molecular exchange cycles are key to understanding bulk superfluidity in these systems.
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