Effects of Quantum Fluctuations on PT -Symmetric Solitons of a Trapped Bose Gas*

Abstract

Abstract Considering the quantum fluctuation effects, the existence and stability of solitons in a Bose-Einstein condensate subjected in a P T -symmetric potential are discussed. Using the variational approach, we investigate how the quantum fluctuation affects the self-localization and stability of the condensate with attractive two-body interactions. The results show that the quantum fluctuation dramatically influences the shape, width, and chemical potential of the condensate. Analytical variational computation also predicts there exists a positive critical quantum fluctuation strength qc with each fixed attractive two-body interaction g 0, if the quantum fluctuation strength q 0 is bigger than qc, there is no bright soliton solution existence. We also study the effects of the quantum fluctuations on the stability of solitons using the Vakhitov-Kolokolov (VK) stability criterion. A robust stable bright soliton will always exist when the quantum fluctuation strength q 0 belongs to the parameter regimes qc ≥ q 0 > 0.