Coexistence of order and chaos at critical points of first-order quantum   phase transitions in nuclei
  We study the interplay between ordered and chaotic dynamics at the critical point of a generic first-order quantum phase transition in the interacting boson model of nuclei. Classical and quantum analyses reveal a distinct behavior of the coexisting phases. While the dynamics in the deformed phase is robustly regular, the spherical phase shows strongly chaotic behavior in the same energy intervals. The effect of collective rotations on the dynamics is investigated. 
M. Macek and A. Leviatan
nucl-th