Chaotic billiard lasers

摘要

Physicists have worried for some time about what happens when chaos and quantum mechanics meet. Chaos refers to a generic effect of nonlinear forces in classical physics: the final state of a system depends with exponential sensitivity on the initial conditions. In a practical sense, therefore, it is unpredictable -the 'butterfly effect' made famous in fiction and film. Conversely, quantum mechanics is governed by linear equations, but to reproduce classical behaviour on macroscopic scales it must somehow contain the seeds of chaos.