THE FLARE-IN TEXTURE IN ROTATING SUPERFLUID HE-3-B

A new first-order phase transition is proposed to manifest itself in rotating 3He-B for the vortex-free state, owing to counterflow. The 'flare-out' texture is found to become spontaneously unstable towards a new 'flare-in' texture, which is suggested to explain the transition, first observed with the use of NMR by Hakonen and Nummila in 1987 and confirmed by Korhonen and co-workers in 1989, to a previously unidentified state characterised by a signal corresponding to beta =90 degrees , i.e., with a vector n perpendicular to H// Omega //z. This transition is also expected to be observable in other experiments, such as ones based on ultrasonic measurements, on the vortex-free state of rotating superfluid 3He-B, a new tenfold splitting of the real squashing mode is predicted to occur for the flare-in texture.