Dynamical and excited-state quantum phase transitions in collective systems

• URL: http://arxiv.org/abs/2205.11199v2
• Date: Thu, 28 Jul 2022 17:04:06 GMT
• Title: Dynamical and excited-state quantum phase transitions in collective systems
• Authors: \'Angel L. Corps, Armando Rela\~no
• Abstract summary: We study dynamical phase transitions (DPTs) in quantum many-body systems with infinite-range interaction. We show that DPTs-I appear as a manifestation of symmetry restoration after a quench from the broken-symmetry phase. We show analytically that DPTs-II are forbidden in these systems for quenches leading a broken-symmetry initial state to the same broken-symmetry phase.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: 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 information of an additional conserved charge 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 that DPTs-II are 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.

Related papers

• Exotic phase transitions in spin ladders with discrete symmetries that emulate spin-1/2 bosons in two dimensions [15.282090777675679]
  We introduce a spin ladder with discrete symmetries designed to emulate a two-dimensional spin-1/2 boson system at half-filling. An exact duality transformation maps it onto a $mathbbZ$ gauge theory of three partons, analogous to the U(1) gauge theory of chargons and spinons in two-dimensional spin-1/2 boson systems.
  arXiv  Detail & Related papers  (2024-12-23T19:06:21Z)
• Superradiant phase transitions in the quantum Rabi model: Overcoming the no-go theorem through anisotropy [30.342686040430962]
  Superradiant phase transition (SRPT) is prohibited in the paradigmatic quantum Rabi model. We show two distinct types of SRPTs emerging from the normal phase in the anisotropic quantum Rabi model. Work may open a new avenue for observing SRPTs in their intrinsic form without altering the $mathbfA$-square term.
  arXiv  Detail & Related papers  (2024-12-11T11:33:29Z)
• Boundary anomaly detection in two-dimensional subsystem symmetry-protected topological phases [20.518529676631122]
  We develop a method to detect quantum anomalies in systems with subsystem symmetry. Using numerical simulations, we demonstrate the power of this method by identifying strong and weak $Ztautimes Zsigma$ SSPT phases. We extend the anomaly indicator to mixed-state density matrices and show that quantum anomalies of subsystem symmetry can persist under both uniform and alternating disorders.
  arXiv  Detail & Related papers  (2024-12-10T14:53:54Z)
• Squeezing and Entanglement Dynamics in Phase-Sensitive Non-Hermitian Systems [0.46603287532620746]
  In this study, we construct a phase-sensitive non-Hermitian wave mixing model that inherently possesses single-mode APT symmetry. By tuning the phase of the pump field, this model simultaneously exhibits two-mode quadrature-PT symmetry. Our work further explores the relationship between two-mode quantum entanglement and the phase of the pump field, offering deeper insight into the generation and evolution of entanglement in the corresponding nonlinear system.
  arXiv  Detail & Related papers  (2024-12-05T07:04:45Z)
• Strong-to-weak spontaneous symmetry breaking meets average symmetry-protected topological order [17.38734393793605]
  We propose a new class of phases, termed the double ASPT phase, which emerges from a nontrivial extension of these two orders. This new phase is absent from prior studies and cannot exist in conventional closed systems.
  arXiv  Detail & Related papers  (2024-10-17T16:36:53Z)
• Study of quantum phase transition and entanglement in coupled top systems with standard and nonstandard symmetries under Floquet formalism [15.699822139827916]
  We study an effective time-independent Hamiltonian of a coupled kicked-top (CKT) system derived using the Van Vleck-based perturbation theory at the high-frequency driving limit under Floquet formalism. We study classical and quantum versions of this coupled top system for torsion-free and nonzero torsion cases.
  arXiv  Detail & Related papers  (2024-09-13T06:36:41Z)
• Theory of free fermions dynamics under partial post-selected monitoring [49.1574468325115]
  We derive a partial post-selected Schrdinger"o equation based on a microscopic description of continuous weak measurement. We show that the passage to the monitored universality occurs abruptly at finite partial post-selection. Our approach establishes a way to study MiPTs for arbitrary subsets of quantum trajectories.
  arXiv  Detail & Related papers  (2023-12-21T16:53:42Z)
• Characterizing dynamical phase transitions in a spinor Bose-Einstein condensate via quantum and semiclassical analyses [8.437514200532176]
  We show analytically how to determine the critical quenches by means of the semiclassical approach. We reveal that the occurrence of DPTs is closely connected to the separatrix in the underlying classical system.
  arXiv  Detail & Related papers  (2023-10-24T13:51:26Z)
• Theory of dynamical phase transitions in collective quantum systems [0.0]
  We present a theory for the two kinds of dynamical quantum phase transitions, sometimes termed DPT-I and DPT-II, in collective many-body systems. For quenches below the critical energy, the existence of an additional conserved charge, identifying the corresponding phase, allows for a non-zero value of the dynamical order parameter characterizing DPTs-I.
  arXiv  Detail & Related papers  (2022-05-06T18:38:24Z)
• Dynamical quantum phase transitions in the one-dimensional extended Fermi-Hubbard model [0.0]
  We study the emergence of dynamical quantum phase transitions (DQPTs) in a half-filled one-dimensional lattice. We identify several types of sudden interaction quenches which lead to DQPTs. State-of-the-art cold-atom quantum simulators constitute ideal platforms to implement several reported DQPTs experimentally.
  arXiv  Detail & Related papers  (2021-09-16T04:12:50Z)
• Identifying and harnessing dynamical phase transitions for quantum-enhanced sensing [0.0]
  We use the quantum Fisher information (QFI) to diagnose a dynamical phase transition (DPT) in a closed quantum system. Motivated by the QFI as a quantifier of metrologically useful correlations and entanglement, we also present a robust interferometric protocol.
  arXiv  Detail & Related papers  (2021-03-24T18:03:19Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.