Nucleation and pinning of continuous vortices in superfluid 3He-A

Only after introducing multiple domain walls to the lˆ‐texture, we observed strong pinning of vorticity. In this case, the hysteretic dependences of the trapped vorticity on the maximal angular velocity of rotation were found to be fairly universal for both slab thicknesses and different densities of domain walls. A phenomenological model of a critical state set by either the critical velocity for vortex nucleation or pinning strength is in good agreement with all observations.