First-order quantum phase transitions: test ground for emergent chaoticity, regularity and persisting symmetries
arXiv:1404.0604 · doi:10.1016/j.aop.2014.08.019
Abstract
We present a comprehensive analysis of the emerging order and chaos and enduring symmetries, accompanying a generic (high-barrier) first-order quantum phase transition (QPT). The interacting boson model Hamiltonian employed, describes a QPT between spherical and deformed shapes, associated with its U(5) and SU(3) dynamical symmetry limits. A classical analysis of the intrinsic dynamics reveals a rich but simply-divided phase space structure with a Hénon-Heiles type of chaotic dynamics ascribed to the spherical minimum and a robustly regular dynamics ascribed to the deformed minimum. The simple pattern of mixed but well-separated dynamics persists in the coexistence region and traces the crossing of the two minima in the Landau potential. A quantum analysis discloses a number of regular low-energy U(5)-like multiplets in the spherical region, and regular SU(3)-like rotational bands extending to high energies and angular momenta, in the deformed region. These two kinds of regular subsets of states retain their identity amidst a complicated environment of other states and both occur in the coexistence region. A symmetry analysis of their wave functions shows that they are associated with partial U(5) dynamical symmetry (PDS) and SU(3) quasi-dynamical symmetry (QDS), respectively. The pattern of mixed but well-separated dynamics and the PDS or QDS characterization of the remaining regularity, appear to be robust throughout the QPT. Effects of kinetic collective rotational terms, which may disrupt this simple pattern, are considered.
76 pages, 35 figures. Final version, Annals of Physics, in press
References in corpus (9)
- Excited state quantum phase transitions in many-body systems
- Quantum phase transitions in the interacting boson model
- Impact of Quantum Phase Transitions on Excited Level Dynamics
- Partial Dynamical Symmetry at Critical-Points of Quantum Phase Transitions
- Quantum Monte Carlo Study of a Resonant Bose-Fermi Mixture
- Spectral properties of Bunimovich mushroom billiards
- Finite-size scaling exponents in the interacting boson model
- Quantum chaos in the nuclear collective model: I. Classical-quantum correspondence
- Quantum chaos in the nuclear collective model: II. Peres lattices