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

摘要

Considering the quantum fluctuation effects, the existence and stability of solitons in a Bose-Einstein condensate subjected in a PT-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 q(c) with each fixed attractive two-body interaction q(0), if the quantum fluctuation strength q(0) is bigger than q(c), 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 q(c) >= q(0) > 0.