  We theoretically investigate prospects for the creation of nonclassical spin
states in trapped ion arrays by coupling to a squeezed state of the collective
motion of the ions. The correlations of the generated spin states can be
tailored for quantum-enhanced sensing of global or differential rotations of
sub-ensembles of the spins by working with specific vibrational modes of the
ion array. We propose a pair of protocols to utilize the generated states and
determine the impact of finite size effects, inhomogeneous couplings between
the spin and motional degrees of freedom and technical noise. Our work suggests
new opportunities for the preparation of many-body states with tailored
correlations for quantum-enhanced metrology in spin-boson systems.
