TIME-DEPENDENT SPECIFIC-HEAT OF A MAGNETIC QUANTUM TUNNELING SYSTEM

We apply Pauli's master equation to spin tunneling in Mn-12 acetate, a nd argue that the corresponding relaxation is exponential in time. Tak ing advantage of this simplification we calculate the frequency depend ent specific heat. The results are compared with recently obtained exp erimental ones. We also predict results for experiments in which spin tunneling through lower-energy levels can easily be probed by applying a field transversely to the anisotropy axis.