Collisionless sound in a uniform two-dimensional Bose gas
| Autor: | Ota, Miki, Larcher, Fabrizio, Dalfovo, Franco, Pitaevskii, Lev, Proukakis, Nikolaos P., Stringari, Sandro |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 121, 145302 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.121.145302 |
| Popis: | Using linear response theory within the Random Phase Approximation, we investigate the propagation of sound in a uniform two dimensional (2D) Bose gas in the collisionless regime. We show that the sudden removal of a static density perturbation produces a damped oscillatory behavior revealing that sound can propagate also in the absence of collisions, due to mean-field interaction effects. Our analysis points out the crucial role played by Landau damping. We support our predictions by performing numerical simulations with the stochastic (projected) Gross-Pitaevskii equation. The results are consistent with the recent experimental observation of sound in a weakly interacting 2D Bose gas both below and above the superfluid Berezinskii-Kosterlitz-Thouless transition. Comment: Main text: 4 pages, 4 figures + Supplementary material: 2 page. The general structure has been revised for clarity, with improved introduction and conclusions. Accepted for publication in Physical Review Letters |
| Databáze: | arXiv |
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