Vortex Stabilization in Dilute Bose-Einstein Condensate Under Rotation

Abstract

The stability of a quantized vortex state in Bose-Einstein condensationis examined within Bogoliubov theory for alkali atom gases confined in a harmonic potential under forced rotation.By solving the non-linear Bogoliubovequations coupled with the Gross-Pitavskii equation, the elementary excitations and the totalenergy of the systems are calculated as a function of rotation velocity.There are two distinct criteria of vortex stability;The position of the excitation energy levels relative to the condensate energy levelyields the local stability criterion, andthe total energy relative to that ofthe non-vortex stateyields the global stability criterion.The vortex stability phase diagram in the rotation velocity vs theparticle density of the system is obtained, allowing one to locate the appropriate regionto observe the singly quantized vortex.