We have revealed that the barrier-tunneling process in nonintegrable systems is strongly linked to chaos in complex phase space by investigating a simple scattering map model. The semiclassical wave function reproduces complicated features of tunneling perfectly and it enables us to solve all the reasons why those features appear in spite of absence of chaos on the real plane. Multigeneration structure of manifolds, which is the manifestation of complex-domain homoclinic entanglement created by complexified classical dynamics, allows a symbolic coding and it is used as a guiding principle to extract dominant complex trajectories from all the semiclassical candidates.

• Received 24 July 2000

DOI:https://doi.org/10.1103/PhysRevE.64.025201