Critical rotation of an annular superfluid Bose-Einstein condensate
Critical rotation of an annular superfluid Bose-Einstein condensate
We analyze the excitation spectrum of a superfluid Bose-Einstein condensate rotating in a ring trap. We identify two important branches of the spectrum related to outer and inner edge surface modes that lead to the instability of the superfluid. Depending on the initial circulation of the annular condensate, either the …