Experiments on Vortices in Rotating SuperfluidHe3-A

A satellite peak has been observed in the NMR spectrum of rotating ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$; the peak intensity depends linearly on $\Omega$ at the high angular velocities, $\Omega =0.6-1.5\mathrm{}$ rad/s, needed to resolve it. The frequency shift of the satellite is independent of $\Omega$. These results strongly suggest the existence of vortices in rotating ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ with the vortex density proportional to $\Omega$. Another satellite peak also has been observed which probably is due to solitons.