Energy spectrum of harmonically trapped two-component Fermi gases: Three- and Four-Particle Problem

Jun, 2010
23 pages
Published in:
  • Phys.Rev.A 81 (2010) 053615
e-Print:

Citations per year

201120142017202020223012
Abstract: (arXiv)
Trapped two-component Fermi gases allow for the investigation of the so-called BCS-BEC crossover by tuning the interspecies atom-atom ss-wave scattering length scattering a(aa)a^{(aa)} from attractive to repulsive, including vanishing and infinitely large values. Here, we numerically determine the energy spectrum of the equal-mass spin-balanced four-fermion system---the smallest few-particle system that exhibits BCS-BEC crossover-like behavior---as a function of a(aa)a^{(aa)} using the stochastic variational approach. For comparative purposes, we also treat the two- and three-particle systems. States with vanishing and finite total angular momentum as well as with natural and unnatural parity are considered. In addition, the energy spectrum of weakly-attractive and weakly-repulsive gases is characterized by employing a perturbative framework that utilizes hyperspherical coordinates. The hyperspherical coordinate approach allows for the straightforward assignment of quantum numbers and furthermore provides great insights into the strongly-interacting unitary regime.
  • 34.50.-s
  • 05.30.Fk
  • 03.75.Ss
  • energy spectrum: calculated
  • Fermi gas
  • atom: scattering length
  • angular momentum
  • quantum number
  • numerical calculations: variational
  • stochastic