Magnetic resonance within vortex cores in the B phase of superfluid 3He

We investigate a magnetic susceptibility of vortices in the B phase of multicomponent triplet superfluid 3He focusing on a contribution of bound fermionic states localized within vortex cores. Several order-parameter configurations relevant to different types of quantized vortices in 3He B are considered. It is shown quite generally that an ac magnetic susceptibility has a sharp peak at the frequency corresponding to the energy of interlevel spacing in the spectrum of bound fermions. We suggest that measuring of a magnetic resonance within vortex cores can provide a direct probe of a discrete spectrum of bound vortex-core excitations.