Using a generalized transfer matrix method we exactly solve a Schrödinger-like equation in a time periodic potential, with discretized Euclidean space-time. The ground state wave function propagates in space and time with an oscillating solitonlike wave packet and the wave front is wedge shaped. In a statistical mechanics framework our solution represents the partition sum of a directed polymer subjected to a potential layer with alternating (attractive and repulsive) pinning centers.

• Received 11 April 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.4118