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Renormalized atomic interaction and quadrupole excitations of cold Fermi gas near Feshbach resonance

Lai-Wa Siu·T. T. S. Kuo·B. A. Gelman
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Abstract

We present a model space particle-hole Green's function calculation for the quadrupole excitations of cold Fermi gas near Feshbach resonance using a simple model where atoms are confined in a harmonic oscillator potential. Both the Tamm-Dancoff and random phase approximations are employed. By summing up exactly the ladder diagrams between a pair of interacting atoms to all orders, we obtain a renormalized atomic interaction which has well defined and identical limits as the scattering length tends to $\pm \infty$. The experimentally observed abrupt rise in the excitation spectrum and its associated large decay width are satisfactorily reproduced by our calculation.

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Lai-Wa Siu, T. T. S. Kuo, B. A. Gelman. 2006-09-12. Renormalized atomic interaction and quadrupole excitations of cold Fermi gas near Feshbach resonance. https://arxiv.org/abs/cond-mat/0609290

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