Magnetic Vortices in Rotating Superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$B$

Rotating superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$B$ is found to possess a new contribution to the NMR frequency shift, which changes sign on reversal of either the angular velocity of rotation or the magnetic field. For $p=29.3\mathrm{}$ bars this gyromagnetic effect shows a discontinuity in magnitude at the first-order phase-transition temperature $\frac{T}{T_c}=0.6\mathrm{}$, at which a change in the vortex-core structure takes place. These observations support the conclusion that the vortex core possesses a spontaneous intrinsic magnetization.