A1 Journal article (refereed)
Small-amplitude collective modes of a finite-size unitary Fermi gas in deformed traps (2019)


Fei, N., Pei, J. C., Wang, K., & Kortelainen, M. (2019). Small-amplitude collective modes of a finite-size unitary Fermi gas in deformed traps. Physical Review A, 100(5), Article 053613. https://doi.org/10.1103/PhysRevA.100.053613


JYU authors or editors


Publication details

All authors or editors: Fei, Na; Pei, J. C.; Wang, K.; Kortelainen, M.

Journal or series: Physical Review A

ISSN: 2469-9926

eISSN: 2469-9934

Publication year: 2019

Volume: 100

Issue number: 5

Article number: 053613

Publisher: American Physical Society

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevA.100.053613

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/66412

Web address of parallel published publication (pre-print): https://arxiv.org/abs/1907.13473


Abstract

We have investigated collective breathing modes of a unitary Fermi gas in deformed harmonic traps. The ground state is studied by the superfluid local density approximation (SLDA) and small-amplitude collective modes are studied by the iterative quasiparticle random phase approximation (QRPA). The results illustrate the evolutions of collective modes of a small system in traps from spherical to elongated or pancake-shaped deformations. For small spherical systems, the influences of different SLDA parameters are significant, and, in particular, a large pairing strength can shift up the oscillation frequency of collective modes. The transition currents from QRPA show that the compressional flow patterns are nontrivial and dependent on the deformation. Finally, the finite-size effects are demonstrated to be reasonable when progressing towards larger systems. The hydrodynamical results of collective frequencies can be reproduced by SLDA-QRPA with reduced pairing strengths. Our studies indicate that experiments on small and medium systems are valuable for understanding effective interactions in systems with varying sizes and trap deformations.


Keywords: density functional theory

Free keywords: density functional theory; fermi gases; ultracold gases; random phase approximation


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Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 2


Last updated on 2021-09-06 at 15:55