Chinese Physics Letters
Variational Approach to Study ${\mathscr{P}}{\mathscr{T}}$-Symmetric Solitons in a Bose–Einstein Condensate with Non-locality of Interactions
Wei Qi, Haifeng Li, Zhaoxin Liang
Abstract
Considering the non-locality of interactions in a Bose–Einstein condensate, the existence and stability of solitons subject to a - symmetric potential are discussed. In the framework of the variational approach, we investigate how the non-locality of interactions affects the self-localization and stability of a condensate with attractive two-body interactions. The results reveal that the non-locality of interactions dramatically influences the shape, width, and chemical potential of the condensate. Analytically variational computation also predicts that there exists a critical negative non-local interaction strength ( p c < 0) with each fixed two-body interaction ( g 0 < 0), and there exists no bright soliton solution for p 0 < p c . Furthermore, we study the effect of the non-locality interactions on the stability of the solitons using the Vakhitov–Kolokolov stability criterion. It is shown that for a positive non-local interaction ( p 0 > 0), there always exist stable bright solitons in some appropriate parameter regimes .