Transition between nonsingular vortices in superfluid 3He-A at zero magnetic field
Torizuka K., Pekola J. P., Manninen A. J., Volovik G. E.
Rotating 3He-^4 in zero magnetic field exhibits a new first-order phase transition which was discovered by ultrasonic measurements at high angular velocity, ilc ~ 3 rad/s. A possible mechanism of the observed phase change, which is related to the surface vortex layer, is discussed.