Excited-state quantum phase transitions and their manifestations in an extended Dicke model

Abstract

An Excited-State Quantum Phase Transition (esqpt) is a singularity observed in quantum energy spectra in the infinite-size limit of the system. It originates in the existence of stationary points in the semiclassical Hamiltonian function.

We review the classification of esqpts and present a case study in an extended Dicke model. Finally, we show some preliminary results on the dynamical effect induced by esqpts.

Keywords

• systems
• dynamics
• freedom