A semiclassical condition for chaos based on Pesin theorem
  A semiclassical method to determine if the classical limit of a quantum system is chaotic or not, based on Pesin theorem, is presented. The method is applied to a phenomenological Gamow--type model and it is concluded that its classical limit is chaotic. 
Ignacio Gomez, Marcelo Losada, Sebastian Fortin, Mario Castagnino and   Mariela Portesi
quant-ph