Quantum frustration of dissipation by a spin bath

We investigate the evolution of a central spin coupled to a spin bath without internal dynamics. We compare the cases where the bath couples to one or two components of the spin. It is found that the central spin dynamics is enhanced in the latter case, which may be interpreted as a frustration of dissipation. However, the quantum purity of the spin decays fast in both scenarios. We conclude that symmetric coupling of the bath to two orthogonal components of the spin inhibits dissipation but not decoherence.