تقرير
Propagation of first and second sound in a two-dimensional Fermi superfluid
| العنوان: | Propagation of first and second sound in a two-dimensional Fermi superfluid |
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| المؤلفون: | Tononi, A., Cappellaro, A., Bighin, G., Salasnich, L. |
| المصدر: | Phys. Rev. A 103, L061303 (2021) |
| سنة النشر: | 2020 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Quantum Gases |
| الوصف: | Sound propagation is a macroscopic manifestation of the interplay between the equilibrium thermodynamics and the dynamical transport properties of fluids. Here, for a two-dimensional system of ultracold fermions, we calculate the first and second sound velocities across the whole BCS-BEC crossover and we analyze the system response to an external perturbation. In the low-temperature regime we reproduce the recent measurements [Phys Rev. Lett. {\bf 124}, 240403 (2020)] of the first sound velocity, which, due to the decoupling of density and entropy fluctuations, is the sole mode excited by a density probe. Conversely, a heat perturbation excites only the second sound, which, being sensitive to the superfluid depletion, vanishes in the deep BCS regime, and jumps discontinuously to zero at the Berezinskii-Kosterlitz-Thouless superfluid transition. A mixing between the modes occurs only in the finite-temperature BEC regime, where our theory converges to the purely bosonic results. Comment: 6 pages, 3 figures; published version, correction of journal reference |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevA.103.L061303 |
| URL الوصول: | http://arxiv.org/abs/2009.06491 |
| رقم الأكسشن: | edsarx.2009.06491 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevA.103.L061303 |
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