RT Journal Article T1 Signatures of excited-state quantum phase transitions in quantum many-body systems: Phase space analysis A1 Wang, Qian A1 Pérez Bernal, Francisco AB Using the Husimi quasiprobability distribution, we investigate the phase space signatures of excited-state quantum phase transitions (ESQPTs) in the Lipkin-Meshkov-Glick and coupled top models. We show that the ESQPT is evinced by the dynamics of the Husimi function, that exhibits a distinct time dependence in the different ESQPT phases. We also discuss how to identify the ESQPT signatures from the long-time averaged Husimi function and its associated marginal distributions. Moreover, from the calculated second moment and Wherl entropy of the long-time averaged Husimi function, we estimate the critical points of the ESQPT in both models, obtaining a good agreement with analytical (mean field) results. We provide a firm evidence that phase space methods are both a new probe for the detection and a valuable tool for the study of ESQPTs. PB American Physical Society SN 2470-0045 SN 2470-0053 (electrónico) YR 2021 FD 2021 LK http://hdl.handle.net/10272/20614 UL http://hdl.handle.net/10272/20614 LA eng NO Wang, Q., & Pérez-Bernal, F. (2021). Signatures of excited-state quantum phase transitions in quantum many-body systems: Phase space analysis. In Physical Review E (Vol. 104, Issue 3). American Physical Society (APS). https://doi.org/10.1103/physreve.104.034119 DS Repositorio Institucional de la Universidad de Huelva RD 30 may 2026