QUANTUM IRREVERSIBILITY AND CHAOS

Herein we establish a relation between quantum irreversibility and the chaotic semi-classical solutions for a spin-boson Hamiltonian system. We obtain quantum averages by numerically integrating the appropriate Liouville-Von Neumann equations of motion and find these averages to be less erratic than the corresponding chaotic semi-classical trajecto ries. However, the quantum averages are shown to be dissipative as mea sured by the entropy of the spin subsystem and to suppress the phenome non of ''revivals''.