Investigation of spin supercurrents inB3

Magnetic supercurrents are observed in superfluid ${}_{}{}^3{}_{}{}^{}\mathit{B}$. These supercurrents transport the longitudinal magnetization from one experimental cell to another through a narrow channel, driven by gradients of the order parameter. In both cells NMR is induced by separate signal generators at the same frequency. The supercurrent arises if a phase difference of the magnetization precession is established across the narrow channel. A critical spin supercurrent is measured at which precession phase slippage takes place. Experimental values of the critical spin supercurrent are in agreement with theoretical predictions.