Vortex-free state of3He-B in a rotating cylinder

Vortex-free states have been observed in ${}_{}{}^3{}_{}{}^{}\mathit{B}$ at rotation speeds up to 0.9 rad/s in a cylinder of 5-mm diameter. The measured cw NMR spectra, reflecting the order-parameter structure, respond very differently to rotation in opposite directions. The sign of this asymmetry is not linked to the direction of the applied magnetic field, as expected for a gyromagnetic effect, but varies randomly from one cooldown to another.