Cusp bifurcation in the eigenvalue spectrum of PT -symmetric Bose-Einstein condensates

摘要: A Bose-Einstein condensate in a double-well potential features stationary solutions even for attractive contact interaction as long the particle number and therefore strength do not exceed certain limit. Introducing balanced gain loss into such system drastically changes bifurcation scenario at which these states are created. Instead of two tangent bifurcations symmetric antisymmetric emerge, one between formerly independent branches arises [D. Haag et al., Phys. Rev. 89, 023601 (2014)]. We study this transition detail using bicomplex formulation time-dependent variational principle find that fact there three very small gain-loss contributions coalesce cusp bifurcation.