Contents

We consider a class of nonlinear Schrödinger / Gross-Pitaveskii (NLS-GP) equa-tions, i.e. NLS with a linear potential. We obtain conditions for a symmetry breaking bifurcation in a symmetric family of states asN, the squared L2 norm (particle number, optical power), is increased. In the special case where the linear potential is a double-well with well separation L, we estimate Ncr(L), the symmetry breaking threshold. Along the “lowest energy ” symmetric branch, there is an exchange of stability from the symmetric to asymmetric branch as N is increased beyond Ncr