Semiclassical wave-function patterns in a pulsed spin system are examined in the post crossover-time regime. They show ergodic and nonergodic features possessed by the underlying classical dynamics. Local dimensions (i.e., singularities) of their probability density functions maintain enhanced fluctuations when the pulse strength lies in a transitional region leading to global chaos.

• Received 17 February 1989

DOI:https://doi.org/10.1103/PhysRevB.39.12422