Excited state quantum phase transitions in many-body systems

Understand

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 excited state phase transitions are manifested as simultaneous singularities in the eigenvalue spectrum (including the gap or level density), order parameters, and wave function properties.
• In this article, the characteristics of excited state quantum phase transitions are investigated.
• The finite-size scaling behavior is determined at the mean field level.