Interplay of order and chaos across a first-order quantum shape-phase   transition in nuclei
  We study the nature of the dynamics in a first-order quantum phase transition between spherical and prolate-deformed nuclear shapes. Classical and quantum analyses reveal a change in the system from a chaotic H\'enon-Heiles behavior on the spherical side into a pronounced regular dynamics on the deformed side. Both order and chaos persist in the coexistence region and their interplay reflects the Landau potential landscape and the impact of collective rotations. 
A. Leviatan and M. Macek
nucl-th nlin.CD quant-ph