Progress of Theoretical Physics
On the Extra Phase Accompanying Berry's Phase in Terms of Coherent State Path Integral
Takahiro Fukui
Abstract
In the WKB approximation for coupled channel equations, it has been pointed out by Yabana and Horiuchi that the semi-classical quantization condition should be modified by Berry's phase and another extra phase. Recently Littlejohn and Flynn have rederived them in a quite elegant way. We concentrate on this extra phase in this paper, and derive it for a simple model by means of the path integral method in the generalized coherent state representation. It is shown that it appears as a quantum fluctuation around classical orbits.