Phenomena analogous to ground state quantum phase transitions have recently been noted
to occur among states throughout the excitation spectra of certain many-body models. These …

We study the structure of the eigenstates and the dynamics of a system that undergoes an
excited-state quantum phase transition (ESQPT). The analysis is performed for two-level …

Excited-state quantum phase transitions (ESQPTs) are generalizations of quantum phase
transitions to excited levels. They are associated with local divergences in the density of …

We analyze shape phase transitions in two-dimensional algebraic models. We apply our
analysis to linear-to-bent transitions in molecules and point out what observables are …

Signatures of quantum phase transitions (QPTs) and excited state quantum phase
transitions (ESQPTs) in the bending motion of eight XYZ triatomic molecules (HCN, HNC …

We analyze the decoherence induced on a single qubit by the interaction with a two-level
boson system with critical internal dynamics. We explore how the decoherence process is …

We present an extension of the Hamiltonian of the two dimensional limit of the vibron model
to encompass all possible interactions up to four-body operators. We apply this Hamiltonian …

The basic Lipkin-Meshkov-Glick model displays a second-order ground-state quantum
phase transition and an excited-state quantum phase transition (ESQPT). The inclusion of …

We present a theory characterizing the phases emerging as a consequence of continuous
symmetry-breaking in quantum and classical systems. In symmetry-breaking phases …

Recent works have shown that the spectroscopic access to highly excited states provides
enough information to characterize transition states in isomerization reactions. Here, we …