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Title: Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects

Abstract

This article extends our previous analysis Stránský et al. (2014) of Excited-State Quantum Phase Transitions (ESQPTs) in systems of dimension two. We focus on the oscillatory component of the quantum state density in connection with ESQPT structures accompanying a first-order ground-state transition. It is shown that a separable (integrable) system can develop rather strong finite-size precursors of ESQPT expressed as singularities in the oscillatory component of the state density. The singularities originate in effectively 1-dimensional dynamics and in some cases appear in multiple replicas with increasing excitation energy. Using a specific model example, we demonstrate that these precursors are rather resistant to proliferation of chaotic dynamics. - Highlights: • Oscillatory components of state density and spectral flow studied near ESQPTs. • Enhanced finite-size precursors of ESQPT caused by fully/partly separable dynamics. • These precursors appear due to criticality of a subsystem with lower dimension. • Separability-induced finite-size effects disappear in case of fully chaotic dynamics.

Authors:
 [1];  [1];  [2];  [3];  [1]
  1. Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague (Czech Republic)
  2. (United States)
  3. Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)
Publication Date:
OSTI Identifier:
22451163
Resource Type:
Journal Article
Journal Name:
Annals of Physics
Additional Journal Information:
Journal Volume: 356; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-4916
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CHAOS THEORY; DEGREES OF FREEDOM; EXCITED STATES; GROUND STATES; ONE-DIMENSIONAL CALCULATIONS; PHASE TRANSFORMATIONS; QUANTUM STATES

Citation Formats

Stránský, Pavel, Macek, Michal, Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120, Leviatan, Amiram, and Cejnar, Pavel, E-mail: pavel.cejnar@mff.cuni.cz. Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects. United States: N. p., 2015. Web. doi:10.1016/J.AOP.2015.02.025.
Stránský, Pavel, Macek, Michal, Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120, Leviatan, Amiram, & Cejnar, Pavel, E-mail: pavel.cejnar@mff.cuni.cz. Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects. United States. doi:10.1016/J.AOP.2015.02.025.
Stránský, Pavel, Macek, Michal, Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120, Leviatan, Amiram, and Cejnar, Pavel, E-mail: pavel.cejnar@mff.cuni.cz. Fri . "Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects". United States. doi:10.1016/J.AOP.2015.02.025.
@article{osti_22451163,
title = {Excited-state quantum phase transitions in systems with two degrees of freedom: II. Finite-size effects},
author = {Stránský, Pavel and Macek, Michal and Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120 and Leviatan, Amiram and Cejnar, Pavel, E-mail: pavel.cejnar@mff.cuni.cz},
abstractNote = {This article extends our previous analysis Stránský et al. (2014) of Excited-State Quantum Phase Transitions (ESQPTs) in systems of dimension two. We focus on the oscillatory component of the quantum state density in connection with ESQPT structures accompanying a first-order ground-state transition. It is shown that a separable (integrable) system can develop rather strong finite-size precursors of ESQPT expressed as singularities in the oscillatory component of the state density. The singularities originate in effectively 1-dimensional dynamics and in some cases appear in multiple replicas with increasing excitation energy. Using a specific model example, we demonstrate that these precursors are rather resistant to proliferation of chaotic dynamics. - Highlights: • Oscillatory components of state density and spectral flow studied near ESQPTs. • Enhanced finite-size precursors of ESQPT caused by fully/partly separable dynamics. • These precursors appear due to criticality of a subsystem with lower dimension. • Separability-induced finite-size effects disappear in case of fully chaotic dynamics.},
doi = {10.1016/J.AOP.2015.02.025},
journal = {Annals of Physics},
issn = {0003-4916},
number = ,
volume = 356,
place = {United States},
year = {2015},
month = {5}
}