Negative group velocity and Kelvin-like wake pattern
| Autor: | Kolomeisky, Eugene B., Colen, Jonathan, Straley, Joseph P. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 105, 054509 (2022) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.105.054509 |
| Popis: | Wake patterns due to a uniformly traveling source are a result of the resonant emission of the medium's collective excitations. When there exists a frequency range where such excitations possess a negative group velocity, their interference leads to a wake pattern resembling the Kelvin ship wake: while there are "transverse" and "divergent" wavefronts trailing the source, they are oriented oppositely to Kelvin's. This is illustrated by an explicit calculation of "roton" wake patterns in superfluid $^{4}He$ where a Kelvin-like wake emerges when the speed of the source marginally exceeds the Landau critical roton velocity. Comment: 5 pages, 2 figures. Modified title and abstract to emphasize general character of discovered effect, minor text changes. Version to be published in Phys. Rev. B |
| Databáze: | arXiv |
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