Semiquantum chaos and the uncertainty principle

With reference to a recently advanced semi-classical model (Cooper et al., Phys. Rev. Lett. 72 (1994) 1337), we study the quantum-averaged behaviour of the coupling between a classical and a quantum system. This composite system is seen to be described in the language of a classical dynamical system. We show that some characteristics of the putative classical-quantum border become amenable to a type of quantitative analysis involving the uncertainty principle.