Nonlinear dynamics in quantum physics- the study of quantum chaos
  We use the quantum action to study the dynamics of quantum system at finite temperature. We construct the quantum action non-perturbatively and find temperature dependent action parameters. Here we apply the quantum action to study quantum chaos. We present a numerical study of a classically chaotic 2-D Hamiltonian system - harmonic oscillators with anharmonic coupling. We compare Poincar\'e sections for the quantum action at finite temperature with those of classical action. 
L.A. Caron, H. Kr\"oger, X.Q. Luo, G. Melkonyan and K.J.M. Moriarty