Equation of state and collective frequencies of a trapped Fermi gas along the BEC-unitarity crossover.
We show that the study of the collective oscillations in a harmonic trap provides a very sensitive test of the equation of state of a Fermi gas near a Feshbach resonance. Using a scaling approach, whose high accuracy is proven by comparison with exact hydrodynamic solutions, the frequencies of the lowest compressional modes are calculated at T=0 in terms of a dimensionless parameter characterizing the equation of state. The predictions for the collective frequencies, obtained from the equations of state of mean-field BCS theory and of recent Monte Carlo calculations, are discussed in detail.
Astrakharchik
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GE
Dipartimento di Fisica, Università di Trento and BEC-INFM, I-38050 Povo, Italy.
Combescot
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Leyronas
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Stringari
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