Multitime-correlation functions and the atomic coherent-state representation
Lorenzo M. Narducci, C. M. Bowden, V. Bluemel, G. P. Garrazana, Richard A. Tuft · Physical Review A · 1975
We consider the evaluation of multitime-correlation functions for quantum statistical systems characterized by dynamical variables of the angular-momentum type (such as, for example, paramagnetic or nuclear spins or collections of two-level atoms), and show how the atomic coherent-state representation of Arecchi et al. can be used to express the multitime averages in terms of phase-space integrals. Our calculation suggests a convenient classical-quantum correspondence rule for angular-momentum degrees of freedom.