Instability of Persistent Currents and Heat Flow in SuperfluidHe3-A

Abstract

A Landau expansion of the normal-mode amplitude shows that the instability of helical textures in a magnetic field parallel to the superflow always occurs as an inverted bifurcation that does not represent a transition to a nearby steady configuration. Above a critical magnetic field, for example, physical arguments show that a persistent current in a torus will be partially quenched, leading to a stable wide-angle helix, but that the corresponding texture in an applied heat flow will oscillate anharmonically.