Non-Hermitian second-order topological superconductors

• URL: http://arxiv.org/abs/2311.18325v2
• Date: Wed, 27 Mar 2024 09:13:33 GMT
• Title: Non-Hermitian second-order topological superconductors
• Authors: Xaing Ji, Wenchen Ding, Yuanping Chen, Xiaosen Yang,
• Abstract summary: We study the interplay between the non-Hermiticity and the second-order topological superconductors in two spatial dimensions. We show that the non-Hermiticity drives both the bulk states and topological edge modes to accumulate toward opposite corners of the system.
• Score: 0.19999259391104385
• License: http://creativecommons.org/publicdomain/zero/1.0/
• Abstract: The topology of non-Hermitian systems is fundamentally changed by the non-Hermitian skin effect, which leads to the generalized bulk-boundary correspondence. Based on the non-Bloch band theory, we get insight into the interplay between the non-Hermiticity and the second-order topological superconductors in two spatial dimensions. We investigate that the non-Hermiticity drives both the bulk states and topological edge modes to accumulate toward opposite corners of the system depending on the particle and hole degrees of freedom protected by the particle-hole symmetry. Furthermore, the degeneracy of the Majorana corner modes can be broken in terms of both the eigenenergies and the eigenstates. Through an edge theory analysis, we elucidate the impact of non-Hermiticity and enable the extension of higher-order topological superconductors to the realm of non-Hermitian systems. We show that $Z_2$ skin effect and $Z_2$ skin-topological modes reveal the universal characteristics of non-Hermitian second-order topological superconductors and the generalized bulk-boundary correspondence is further enriched by the particle-hole symmetry.

Related papers

• Topological Order in the Spectral Riemann Surfaces of Non-Hermitian Systems [44.99833362998488]
  We show topologically ordered states in the complex-valued spectra of non-Hermitian systems. These arise when the distinctive exceptional points in the energy surfaces of such models are annihilated. We illustrate the characteristics of the topologically protected states in a non-Hermitian two-band model.
  arXiv  Detail & Related papers  (2024-10-24T10:16:47Z)
• Non-Hermitian Topology in Hermitian Topological Matter [0.0]
  We show that anomalous boundary states in Hermitian topological insulators exhibit non-Hermitian topology. We also find the emergence of hinge states within effective non-Hermitian Hamiltonians at surfaces of three-dimensional topological insulators. Our work uncovers a hidden connection between Hermitian and non-Hermitian topology, and provides an approach to identifying non-Hermitian topology in quantum matter.
  arXiv  Detail & Related papers  (2024-05-16T11:59:15Z)
• Two-dimensional non-Hermitian skin effect in an ultracold Fermi gas [8.925244794690562]
  We create a non-Hermitian band for ultracold fermions in spin-orbit-coupled optical lattices with tunable dissipation. We observe the real-space dynamical signature of NHSE in real space by monitoring the center of mass motion of atoms. Our work paves the way for understanding the interplay of quantum statistics with NHSE.
  arXiv  Detail & Related papers  (2023-11-14T06:18:33Z)
• Higher-order topological Peierls insulator in a two-dimensional atom-cavity system [58.720142291102135]
  We show how photon-mediated interactions give rise to a plaquette-ordered bond pattern in the atomic ground state. The pattern opens a non-trivial topological gap in 2D, resulting in a higher-order topological phase hosting corner states. Our work shows how atomic quantum simulators can be harnessed to investigate novel strongly-correlated topological phenomena.
  arXiv  Detail & Related papers  (2023-05-05T10:25:14Z)
• Topologically bound states, non-Hermitian skin effect and flat bands, induced by two-particle interaction [91.3755431537592]
  We study theoretically repelling quantum states of two spinless particles in a one-dimensional tight-binding model. We demonstrate, that when the particles are not identical, their interaction drives nontrivial correlated two-particle states.
  arXiv  Detail & Related papers  (2022-11-11T07:34:54Z)
• 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)
• 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)
• Gain/loss effects on spin-orbit coupled ultracold atoms in two-dimensional optical lattices [0.5249805590164902]
  We investigate the corresponding non-Hermitian tight-binding model and evaluate the gain/loss effects on various properties of the system. We find that the conventional bulk-boundary correspondence does not break down with only on-site gain/loss due to the lack of non-Hermitian skin effect. Given the technical accessibility of state-dependent atom loss, this model could be realized in current cold-atom experiments.
  arXiv  Detail & Related papers  (2022-01-04T16:00:30Z)
• Non-Hermitian $C_{NH} = 2$ Chern insulator protected by generalized rotational symmetry [85.36456486475119]
  A non-Hermitian system is protected by the generalized rotational symmetry $H+=UHU+$ of the system. Our finding paves the way towards novel non-Hermitian topological systems characterized by large values of topological invariants.
  arXiv  Detail & Related papers  (2021-11-24T15:50:22Z)
• Topological Higgs Amplitude Modes in Strongly Interacting Superfluids [2.1532925122722744]
  We show the existence of topological Higgs amplitude modes in the strongly interacting superfluid phase. Using the slave boson approach, we find that, in the large filling limit, the Higgs excitations and the Goldstone excitations above the ground state are well decoupled. Our discovery of the first realization of the topological Higgs mode opens the path to novel investigations in various systems.
  arXiv  Detail & Related papers  (2021-07-08T17:43:56Z)
• Dynamical solitons and boson fractionalization in cold-atom topological insulators [110.83289076967895]
  We study the $mathbbZ$ Bose-Hubbard model at incommensurate densities. We show how defects in the $mathbbZ$ field can appear in the ground state, connecting different sectors. Using a pumping argument, we show that it survives also for finite interactions.
  arXiv  Detail & Related papers  (2020-03-24T17:31:34Z)

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.