Photon echoes and Berry's phase.

Abstract

We prove a theorem linking the phase associated with the ballistic evolution of a coherent state of a harmonic oscillator about a jumping vertex to that associated with its adiabatic migration along straight lines connecting the initial and the final points of each ballistic arc to the vertex on which the arc is centered. This equivalence allows one to determine the ballistic phase by Berry's prescription. The method facilitates both the visualization and the calculation of modulation effects (quantum beats) in photon-echo experiments.