WKB FOR A DAMPED SPIN

The master equation for a damped spin well known from the theory of su perradiance, is written as a finite-difference equation and solved by a WKB-like method. The propagator thus obtained looks like the van Vle ck propagator of a certain classical Hamiltonian system with one degre e of freedom. A new interpretation is provided of the temporal broaden ing of initially sharp probability distributions as the analogue of th e spreading of the quantum mechanical wave packet.