Probing non-locality of interactions in a Bose-Einstein condensate using solitons

Abstract

We consider a Bose-Einstein condensate (BEC) with non-local inter-particle interactions. The local Gross-Pitaevskii (GP) equation is valid for the gas parameter v =: a3n0< 1, but for v→ 1, the BEC is described by a modifed GP equation (MGPE). We study the exact solutions of the MGPE describing bright and dark solitons. It turns out that the width of these non-local solitons has qualitatively similar behaviour as the modifed healing length due to the non-local interactions of the MGPE. We also study the effect of the non-locality and gas parameter (?) on the stability of the solitons using the Vakhitov-Kolokolov (VK) stability criterion. We show that these soliton solutions are stable according to the VK criterion. Further, the stability of these soliton solutions gets enhanced due to the non-locality of interactions.