A new effective interaction for the trapped Fermi gas
Abstract
We apply the configuration-interaction method to calculate the spectra of two-component Fermi systems in a harmonic trap, studying the convergence of the method at the unitary interaction limit. We find that for a fixed regularization of the two-body interaction the convergence is exponential or better in the truncation parameter of the many-body space. However, the conventional regularization is found to have poor convergence in the regularization parameter, with an error that scales as a low negative power of this parameter. We propose a new regularization of the two-body interaction that produces exponential convergence for systems of three and four particles. From the systematics, we estimate the ground-state energy of the four-particle system to be (5.05 +- 0.024)hbar omega.
Cite
@article{arxiv.0706.4085,
title = {A new effective interaction for the trapped Fermi gas},
author = {Y. Alhassid and G. F. Bertsch and L. Fang},
journal= {arXiv preprint arXiv:0706.4085},
year = {2015}
}