Hyperspherical-LOCV Approximation to Resonant BEC

ORAL

Abstract

We study the ground state properties of a system of harmonically trapped bosons interacting with two-body contact interactions, from small to large scattering lengths. This is accomplished in a hyperspherical coordinate system that is flexible enough to describe both the overall scale of the gas and two-body correlations. By adapting the lowest-order constrained variational (LOCV) method, we are able to semi-quantitatively attain Bose-Einstein condensate ground state energies even for gases with infinite scattering length. In the large particle number limit, our method provides analytical estimates for the energy per particle $E_0/N \approx 2.5 N^{1/3} \hbar \omega$ and two-body contact $C_2/N \approx 16 N^{1/6}\sqrt{m\omega/\hbar}$ for a Bose gas on resonance.

*JILA NSF Physics Frontier Center, grant number PHY-1734006, and by an ARO MURI Grant, number W911NF-12-1-0476; National Science Foundation through grant numbers PHY- 1509892 and PHY-1745142

–

Authors

  • Michelle Wynne Sze

    • JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA

  • Andrew Sykes

    • LPTMS, CNRS, University Paris Sud, Université Paris-Saclay, 91405 Orsay, France

  • Doerte Blume

    • Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, Oklahoma 73019, USA

  • John Bohn

    • JILA, NIST, and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA