Twisted vortex state
  We study a twisted vortex bundle where quantized vortices form helices circling around the axis of the bundle in a "force-free" configuration. Such a state is created by injecting vortices into rotating vortex-free superfluid. Using continuum theory we determine the structure and the relaxation of the twisted state. This is confirmed by numerical calculations. We also present experimental evidence of the twisted vortex state in superfluid 3He-B. 
V.B. Eltsov, A.P. Finne, R. Hanninen, J. Kopu, M. Krusius, M. Tsubota,   E.V. Thuneberg