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 o f the coupling between a classical and a quantum system. This composite sys tem is seen to be described in the language of a classical dynamical system . We show that some characteristics of the putative classical-quantum borde r become amenable to a type of quantitative analysis involving the uncertai nty principle. 2000 Elsevier Science B.V. All rights reserved.