Unconventional steady states and topological phases in an open two-level non-Hermitian system

• URL: http://arxiv.org/abs/2004.03703v4
• Date: Sat, 28 May 2022 05:40:42 GMT
• Title: Unconventional steady states and topological phases in an open two-level non-Hermitian system
• Authors: Jian Xu and Youneng Guo
• Abstract summary: We study an open two-level non-Hermitian system coupling to a dissipative environment by solving the vectorized Lindblad equation. Our results show that there exist a new class of exceptional points (EPs) and steady states due to the interplay between non-Hermiticity and decoherence. It is revealed that the phases of eigenstates located in Fermi arcs regime have a topological phase $|pi/2|$ which is totally unaffected by the dissipative environment.
• Score: 3.2558897563787674
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Decoherence and non-Hermiticity are two different effects of the open quantum systems. Both of them have triggered many interesting phenomena. In this paper, we theoretically study an open two-level non-Hermitian system coupling to a dissipative environment by solving the vectorized Lindblad equation. This scheme provides us a powerful framework to address widespread open systems with gain, loss and dissipation. Our results show that there exist a new class of exceptional points (EPs) and steady states due to the interplay between non-Hermiticity and decoherence. Furthermore, we also demonstrate new-type topological properties of eigenstates with zero real-part of eigenvalues ($Re[\lambda]=0$) which are corresponding to Fermi arcs. It is revealed that the phases of eigenstates located in Fermi arcs regime have a topological phase $|\pi/2|$ which is totally unaffected by the dissipative environment. Our results provide a promising approach for further uncovering and understanding the intriguing properties of non-Hermitian open systems.

Related papers

• Emergent non-Hermitian models [0.0]
  We use recently developed graph-theoretical tools to design non-Hermitian systems with non-trivial boundary phenomena. We show that eigenstates can simultaneously localize on either ends of the systems, with different localization lengths. We also predict the existence of various topological edge states, pinned at non-zero energies, with different exponential envelopes, depending on their energy.
  arXiv  Detail & Related papers  (2023-10-18T14:19:58Z)
• Recognizing critical lines via entanglement in non-Hermitian systems [0.0]
  We show that the non-Hermitian model can be an effective Hamiltonian of a Hermitian XX spin-1/2 with KSEA interaction and a local magnetic field. We demonstrate that the nearest-neighbor entanglement and its derivative can identify quantum critical lines with the variation of the magnetic field.
  arXiv  Detail & Related papers  (2023-05-15T06:20:56Z)
• Duality between open systems and closed bilayer systems, and thermofield double states as quantum many-body scars [49.1574468325115]
  We find a duality between open many-body systems governed by the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) equation. Under this duality, the identity operator on the open system side maps to the thermofield double state. We identify broad classes of many-body open systems with nontrivial explicit eigen operators $Q$ of the Lindbladian superoperator.
  arXiv  Detail & Related papers  (2023-04-06T15:38:53Z)
• Entanglement and localization in long-range quadratic Lindbladians [49.1574468325115]
  Signatures of localization have been observed in condensed matter and cold atomic systems. We propose a model of one-dimensional chain of non-interacting, spinless fermions coupled to a local ensemble of baths. We show that the steady state of the system undergoes a localization entanglement phase transition by tuning $p$ which remains stable in the presence of coherent hopping.
  arXiv  Detail & Related papers  (2023-03-13T12:45:25Z)
• Quantum Lyapunov exponent in dissipative systems [68.8204255655161]
  The out-of-time order correlator (OTOC) has been widely studied in closed quantum systems. We study the interplay between these two processes. The OTOC decay rate is closely related to the classical Lyapunov.
  arXiv  Detail & Related papers  (2022-11-11T17:06:45Z)
• Detecting bulk and edge exceptional points in non-Hermitian systems through generalized Petermann factors [7.371841894852217]
  Non-orthogonality in non-Hermitian quantum systems gives rise to tremendous exotic quantum phenomena. We introduce an interesting quantity (denoted as $eta$) as a new variant of the Petermann factor to measure non-unitarity.
  arXiv  Detail & Related papers  (2022-08-31T16:24:03Z)
• Pontryagin-Optimal Control of a non-Hermitian Qubit [0.0]
  We study the control of a single non-Hermitian qubit. We show how to realize any continuous and differentiable pure-state trajectory in the dynamics of a qubit conditioned on no emission.
  arXiv  Detail & Related papers  (2022-08-04T20:51:29Z)
• Fast Thermalization from the Eigenstate Thermalization Hypothesis [69.68937033275746]
  Eigenstate Thermalization Hypothesis (ETH) has played a major role in understanding thermodynamic phenomena in closed quantum systems. This paper establishes a rigorous link between ETH and fast thermalization to the global Gibbs state. Our results explain finite-time thermalization in chaotic open quantum systems.
  arXiv  Detail & Related papers  (2021-12-14T18:48:31Z)
• Bridging the gap between topological non-Hermitian physics and open quantum systems [62.997667081978825]
  We show how to detect a transition between different topological phases by measuring the response to local perturbations. Our formalism is exemplified in a 1D Hatano-Nelson model, highlighting the difference between the bosonic and fermionic cases.
  arXiv  Detail & Related papers  (2021-09-22T18:00:17Z)
• Einselection from incompatible decoherence channels [62.997667081978825]
  We analyze an open quantum dynamics inspired by CQED experiments with two non-commuting Lindblad operators. We show that Fock states remain the most robust states to decoherence up to a critical coupling.
  arXiv  Detail & Related papers  (2020-01-29T14:15:19Z)
• Equivalence of the effective non-hermitian Hamiltonians in the context of open quantum systems and strongly-correlated electron systems [0.0]
  We show that non-hermitian phenomena can be observed in both open quantum systems and strongly correlated systems. We propose a method to analyze non-hermitian properties without the necessity of postselection.
  arXiv  Detail & Related papers  (2020-01-24T14:59:15Z)

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.