Quantized Vortices in an Imperfect Bose Gas and the Breakdown of Superfluidity in Liquid Helium II

Abstract

The energy and momentum associated with vortex formation in an imperfect Bose gas have been computed quantum mechanically. In the computation, explicit account is taken of the boundary condition to be satisfied by the wave function at the walls surrounding the fluid. Numerical estimates of the critical velocity obtained thereby throw considerable light on the question of the most favorable location (relative to the walls) for the formation of the vortex. It is concluded that the optimum location for this formation could be well within the fluid—significantly away from the walls.