Finally solved! The great mystery of quantized vortex motion
[ad_1]
Liquid helium-4, which exists in a superfluid state at cryogenic temperatures close to absolute zero (-273°C), has a special eddy called a quantized eddy that originates from quantum mechanical effects. When the temperature is relatively high, the normal fluid simultaneously exists in the superfluid helium, and when the quantized vortex moves, mutual friction occurs between it and the normal fluid. However, it is difficult to explain exactly how the quantized eddies interact with normal moving fluids. Although several theoretical models have been proposed, it is not clear which one is correct.
Liquid helium-4, which exists in a superfluid state at cryogenic temperatures close to absolute zero (-273°C), has a special eddy called a quantized eddy that originates from quantum mechanical effects. When the temperature is relatively high, the normal fluid simultaneously exists in the superfluid helium, and when the quantized vortex moves, mutual friction occurs between it and the normal fluid. However, it is difficult to explain exactly how the quantized eddies interact with normal moving fluids. Although several theoretical models have been proposed, it is not clear which one is correct.
A research group led by specially appointed Professor Makoto Tsubota and Assistant Professor Satoshi Yui, from the Graduate School of Science and the Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University in collaboration with their counterparts from Florida State University and Keio University respectively , investigate numerically the interaction between the quantized eddies and normal fluids. Based on the experimental results, the researcher decides which of the several theoretical models is the most consistent. They found that models that account for changes in the normal fluid and incorporate more theoretically accurate mutual friction are the ones that best fit the experimental results.
“The subject of this study, the interaction between quantized eddies and normal fluids, has been a great mystery since I started research in this area 40 years ago,” said Professor Tsubota. “Computing advances have made it possible to tackle this problem, and brilliant visualization experiments by our collaborators at Florida State University have resulted in a breakthrough. As is often the case in science, subsequent technological developments have made it possible to explain, and this study is a great example of that.”
Their findings are published in Nature Communications.
###
About OMU
Osaka Metropolitan University is the third largest public university in Japan, formed by the merger of Osaka City University and Osaka Prefectural University in 2022. OMU upholds “Knowledge Convergence” through 11 undergraduate schools, colleges, and 15 graduate schools. For more research news, visit https://www.omu.ac.jp/en/ or follow us on Twitter: @OsakaMetUniv_enor Facebook.
Journal
Nature Communications
DOI
10.1038/s41467-023-38787-w
Research methods
Computational simulation/modelling
Research Subjects
Not applicable
Article title
Quantized vortex ring imaging in superfluid helium to evaluate quantum dissipation
Article Publication Date
23-May-2023
[ad_2]
Source link
