title: Structural instability of vortices in Bose-Einstein condensates.
abstract: In this paper we study a gaseous Bose-Einstein condensate and show the following: (i) A minimum value of the interaction is needed for the existence of stable persistent currents. (ii) Vorticity is not a fundamental invariant of the system, as there exists a conservative mechanism which can destroy a vortex and change its sign. (iii) This mechanism is suppressed by strong interactions.
authors.affiliation: Departamento de Matemáticas, E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: García-Ripoll
authors.forename: G
authors.initials: G
authors.lastname: Molina-Terriza
authors.forename: V M
authors.initials: VM
authors.lastname: Pérez-García
authors.forename: L
authors.initials: L
authors.lastname: Torner