Fourth-Order Exceptional Points in Correlated Quantum Many-Body Systems

• URL: http://arxiv.org/abs/2106.11987v1
• Date: Tue, 22 Jun 2021 18:00:06 GMT
• Title: Fourth-Order Exceptional Points in Correlated Quantum Many-Body Systems
• Authors: Lorenzo Crippa, Jan Carl Budich and Giorgio Sangiovanni
• Abstract summary: Non-Hermtian (NH) Hamiltonians have become an important tool with applications ranging from classical meta-materials to quantum many-body systems. Exceptional points, the NH counterpart of spectral degeneracies, are among the paramount phenomena unique to the NH realm. We propose a microscopic model of correlated fermions in three spatial dimensions and demonstrate the occurrence of interaction-induced fourth-order exceptional points.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Non-Hermtian (NH) Hamiltonians effectively describing the physics of dissipative systems have become an important tool with applications ranging from classical meta-materials to quantum many-body systems. Exceptional points, the NH counterpart of spectral degeneracies, are among the paramount phenomena unique to the NH realm. While realizations of second-order exceptional points have been reported in a variety of microscopic models, higher-order ones have largely remained elusive in the many-body context, as they in general require fine tuning in high-dimensional parameter spaces. Here, we propose a microscopic model of correlated fermions in three spatial dimensions and demonstrate the occurrence of interaction-induced fourth-order exceptional points that are protected by chiral symmetry. We demonstrate their stability against symmetry breaking perturbations and investigate their characteristic analytical and topological properties.

Related papers

• Multiple quantum exceptional, diabolical, and hybrid points in multimode bosonic systems: II. Nonconventional PT-symmetric dynamics and unidirectional coupling [0.0]
  We analyze the existence and degeneracies of quantum exceptional, diabolical, and hybrid points of simple bosonic systems. The system dynamics described by non-Hermitian Hamiltonians is governed by the Heisenberg-Langevin equations.
  arXiv  Detail & Related papers  (2024-05-02T18:40:21Z)
• Enhanced Entanglement in the Measurement-Altered Quantum Ising Chain [46.99825956909532]
  Local quantum measurements do not simply disentangle degrees of freedom, but may actually strengthen the entanglement in the system. This paper explores how a finite density of local measurement modifies a given state's entanglement structure.
  arXiv  Detail & Related papers  (2023-10-04T09:51:00Z)
• Theory of robust quantum many-body scars in long-range interacting systems [0.0]
  Quantum many-body scars (QMBS) are exceptional energy eigenstates of quantum many-body systems. We show that the setting of long-range interacting quantum spin systems generically hosts robust QMBS.
  arXiv  Detail & Related papers  (2023-09-21T22:00:40Z)
• Experimental Simulation of Symmetry-Protected Higher-Order Exceptional Points with Single Photons [8.82526178604718]
  We experimentally simulate two-dimensional topological NH band structures using single-photon interferometry. We observe topologically stable third-order EPs obtained by tuning only two real parameters in the presence of symmetry. Our work reveals the abundant and conceptually richer higher-order EPs protected by symmetries.
  arXiv  Detail & Related papers  (2023-03-21T13:22:43Z)
• Non-Gaussian superradiant transition via three-body ultrastrong coupling [62.997667081978825]
  We introduce a class of quantum optical Hamiltonian characterized by three-body couplings. We propose a circuit-QED scheme based on state-of-the-art technology that implements the considered model.
  arXiv  Detail & Related papers  (2022-04-07T15:39:21Z)
• Quantum correlations, entanglement spectrum and coherence of two-particle reduced density matrix in the Extended Hubbard Model [62.997667081978825]
  We study the ground state properties of the one-dimensional extended Hubbard model at half-filling. In particular, in the superconducting region, we obtain that the entanglement spectrum signals a transition between a dominant singlet (SS) to triplet (TS) pairing ordering in the system.
  arXiv  Detail & Related papers  (2021-10-29T21:02:24Z)
• Exceptional Non-Hermitian Phases in Disordered Quantum Wires [0.0]
  We demonstrate the occurrence of nodal non-Hermitian (NH) phases featuring exceptional degeneracies in chiral-symmetric disordered quantum wires. We find that at least two nodal points in the clean Hermitian system are required for exceptional points to be effectively stabilized upon adding disorder.
  arXiv  Detail & Related papers  (2021-02-24T19:00:04Z)
• Spin Entanglement and Magnetic Competition via Long-range Interactions in Spinor Quantum Optical Lattices [62.997667081978825]
  We study the effects of cavity mediated long range magnetic interactions and optical lattices in ultracold matter. We find that global interactions modify the underlying magnetic character of the system while introducing competition scenarios. These allow new alternatives toward the design of robust mechanisms for quantum information purposes.
  arXiv  Detail & Related papers  (2020-11-16T08:03:44Z)
• Simulating Exceptional Non-Hermitian Metals with Single-Photon Interferometry [4.030017427802459]
  We experimentally simulate in a photonic setting non-Hermitian (NH) metals characterized by the topological properties of their nodal band structures. We focus on two distinct types of NH metals: two-dimensional systems with symmetry-protected ELs, and three-dimensional systems possessing symmetry-independent topological ELs in the form of knots.
  arXiv  Detail & Related papers  (2020-11-03T18:00:49Z)
• Unraveling the topology of dissipative quantum systems [58.720142291102135]
  We discuss topology in dissipative quantum systems from the perspective of quantum trajectories. We show for a broad family of translation-invariant collapse models that the set of dark state-inducing Hamiltonians imposes a nontrivial topological structure on the space of Hamiltonians.
  arXiv  Detail & Related papers  (2020-07-12T11:26:02Z)
• Probing chiral edge dynamics and bulk topology of a synthetic Hall system [52.77024349608834]
  Quantum Hall systems are characterized by the quantization of the Hall conductance -- a bulk property rooted in the topological structure of the underlying quantum states. Here, we realize a quantum Hall system using ultracold dysprosium atoms, in a two-dimensional geometry formed by one spatial dimension. We demonstrate that the large number of magnetic sublevels leads to distinct bulk and edge behaviors.
  arXiv  Detail & Related papers  (2020-01-06T16:59:08Z)

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.