Breathing mode frequencies of a rotating Fermi gas in the BCS-BEC crossover region

Abstract

We study the breathing mode frequencies of a rotating Fermi gas trapped in a harmonic plus radial quartic potential. We find that as the radial anharmonicity increases, the lowest order radial mode frequency increases while the next lowest order radial mode frequency decreases. Then at a critical anharmonicity, these two modes merge and beyond this merge the cloud is unstable against the oscillations. The critical anharmonicity depends on both rotational frequency and the chemical potential. As a result of the large chemical potential in the BCS regime, even with a weak anharmonicity the lowest order mode frequency increases with decreasing the attractive interaction. For large enough anharmonicities in the weak coupling BCS limit, we find that the excitation of the breathing mode frequencies make the atomic cloud unstable.

6 pages, 8 fiqures. Formalism is modified to include the effect of negative quartic potential

References in corpus (11)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• Molecular Probe of Pairing in the BEC-BCS Crossover
• Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover
• Critical Rotational Frequency for Superfluid Fermionic Gases across a Feshbach Resonance
• Density waves and supersolidity in rapidly rotating atomic Fermi gases
• Collective oscillations of a Fermi gas near a Feshbach resonance
• Superfluid transition in a rotating resonantly-interacting Fermi gas
• Vortex formation in a slowly rotating Bose-Einstein condensate confined in a harmonic-plus-gaussian laser trap
• Breathing modes of a fast rotating Fermi gas