Classical dynamics and quantum spectra for a nonintegrable three-spin system

Abstract

The classical dynamics and corresponding semiclassical quantum spectra are studied in a classically nonintegrable three-spin system with antiferromagnetic exchange coupling. The statistical average of the local curvatures of the energy diagram, i.e., that of second-order differences of eigenvalues, shows a scaling behavior when the inverse spin magnitude is decreased towards 0. The quasifractal feature of the energy diagram is suggested as a promising indicator of the quantum version of classical chaos.