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Biomedical subjects

R Combescot

Publications and source records attributed to R Combescot.

At least 19 recordsLinked to original sources
PubMed2005

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.

Journal Article↗
PubMed2003

Feshbach resonance in dense ultracold Fermi gases.

We propose a coherent framework allowing one to treat many-body effects in dense ultracold Fermi gases in the presence of a Feshbach resonance. We show that the simple effect of Pauli exclusion induces a strong modification of the basic scattering properties. In particular, this washes out the Feshbach resonance and provides a natural explanation for recent experimental findings.

Journal Article↗
PubMed2002

Hydrodynamic modes in dense trapped ultracold gases.

We consider the hydrodynamic modes for dense trapped ultracold gases, where the interparticle distance is comparable to the scattering length. We show that the experimental determination of the hydrodynamic mode frequencies allows one to obtain quite directly the equation of state of a dense gas. As an example, we investigate the case of two equal fermionic populations in different hyperfine states with attractive interaction.

Journal Article↗