RT Journal Article
T1 Dynamical and excited-state quantum phase transitions in collective systems
A1 Corps, Angel L.
A1 Relaño Pérez, Armando
AB We study dynamical phase transitions (DPTs) in quantum many-body systems with infinite-range interaction, and present a theory connecting the two kinds of known DPTs (sometimes referred to as DPTs-I and DPTs-II) with the concept of excited-state quantum phase transition (ESQPT), traditionally found in collective models. We show that DPTs-I appear as a manifestation of symmetry restoration after a quench from the broken-symmetry phase, the limits between these two phases being demarcated precisely by an ESQPT. We describe the order parameters of DPTs-I with a generalization of the standard microcanonical ensemble incorporating the infor-mation of two additional conserved charges identifying the corresponding phase. We also show that DPTs-I are linked to a mechanism of information erasure brought about by the ESQPT, and quantify this information loss with the statistical ensemble that we propose. Finally, we show analytically the main mechanism for DPTs-II is forbidden in these systems for quenches leading a broken-symmetry initial state to the same broken-symmetry phase, on one side of the ESQPT, and we provide a formulation of DPTs-II depending on the side of the ESQPT where the quench ends. We analyze the connections between various indicators of DPTs-II. Our results are numerically illustrated in the infinite-range transverse-field Ising model and are applicable to a large class of collective quantum systems satisfying a set of conditions.
PB American Physical Society
SN 2469-9950
YR 2022
FD 2022-07-28
LK https://hdl.handle.net/20.500.14352/72945
UL https://hdl.handle.net/20.500.14352/72945
LA eng
NO ©2022 American Physical Society. We gratefully acknowledge discussions with P. Pérez Fernández and J. Dukelsky. This work has been supported by the Spanish Grant No. PGC-2018-094180-B-I00 funded by Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación MCIN/AEI/10.13039/501100011033 and FEDER "A Way of Making Europe". A.L.C. acknowledges financial support from `la Caixa' Foundation (ID 100010434) through the Fellowship No. LCF/BQ/DR21/11880024.
NO Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion
NO FEDER "A Way of Making Europe"
NO Fundación "la Caixa"
DS Docta Complutense
RD 29 abr 2025