Momentum Dependent Higher Partial Wave Interactions in Bose Einstein condensate

TL;DR

This paper investigates how momentum-dependent higher partial wave interactions influence the ground state and density profiles of Bose-Einstein condensates with large scattering lengths, revealing significant differences from contact interactions.

Contribution

It introduces a detailed analysis of momentum-dependent interactions including higher partial waves and Lee-Huang-Yang corrections in BECs, highlighting their impact on observable properties.

Findings

Higher partial wave effects increase with scattering length, exceeding 20% at certain values.

Ground state properties differ significantly between momentum-dependent and contact interactions.

Predicted density variations are experimentally detectable in large scattering length BECs.

Abstract

We have investigated the role of momentum dependent s-wave and higher partial wave strong interactions to determine the ground state properties and the column densities in the Bose-Einstein condensate (BEC) for large scattering length (a) such that ka >>1 even for small values of momentum where the momentum p=(h/2pi)k and k is the wave number. Since the scattering length is large we have included the first correction (Lee-Huang-Yang correction) both for the k-dependent (s-wave + higher partial wave) interactions and k-independent contact interactions (s-wave). We have derived the time-independent equations from the corresponding energy functionals and found that the ground state properties and the column densities differ significantly for these two types of interactions even for moderate values of scattering length (a = 3000 a_0) in BEC of cylindrically trapped 85Rb atoms at 100 nK. The effect of higher partial wave (d-wave) increases with increase in a and it is > 20% for peak density at a= 8700 a_0 which can be experimentally detected. Dependence of column density on particle number density has been studied. Column densities have been compared with experimental results.