QUANTUM CHAOS - AN ENTROPY APPROACH

A new definition of the entropy of a given dynamical system and of an instrument describing the measurement process is proposed within the o perational approach to quantum mechanics. It generalizes other definit ions of entropy, in both the classical and quantum cases. The Kolmogor ov-Sinai (KS) entropy is obtained for a classical system and the sharp measurement instrument. For a quantum system and a coherent states in strument, a new quantity, coherent states entropy, is defined. It may be used to measure chaos in quantum mechanics. The following correspon dence principle is proved: the upper limit of the coherent states entr opy of a quantum map as hBAR --> 0 is less than or equal to the KS-ent ropy of the corresponding classical map.