Non-Hermitian skin effect of dislocations and its topological origin

Abstract

We demonstrate that dislocations in two-dimensional non-Hermitian systems can give rise to density accumulation or depletion through the localization of an extensive number of states. These effects are shown by numerical simulations in a prototype lattice model and expose a different face of non-Hermitian skin effect, by disentangling it from the need for boundaries. We identify a topological invariant responsible for the dislocation skin effect, which takes the form of a ${\mathbb{Z}}_2$ Hopf index that depends on the Burgers vector characterizing the dislocations. Remarkably, we find that this effect and its corresponding signature for defects in Hermitian systems falls outside of the known topological classification based on bulk-defect correspondence.

6+4 pages, 2+2 figures

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Cited by in corpus (25)

• Topological Non-Hermitian skin effect
• Entanglement Phase Transition Induced by the Non-Hermitian Skin Effect
• Hybrid skin-topological modes without asymmetric couplings
• Inner Skin Effects on Non-Hermitian Topological Fractals
• Non-Hermitian skin effect and self-acceleration
• Anomalous Skin Effects in Disordered Systems with a Single non-Hermitian Impurity
• Non-Hermitian Topological Phases: Principles and Prospects
• Non-Hermitian Photonic Lattices: tutorial
• Non-Hermitian Chiral Skin Effect
• Dynamical nonlinear higher-order non-Hermitian skin effects and topological trap-skin phase
• Non-Hermitian dislocation modes: Stability and melting across exceptional points
• Non-Hermitian boundary spectral winding
• Erratic non-Hermitian skin localization
• A brief review of hybrid skin-topological effect
• Direction reversal of non-Hermitian skin effect via coherent coupling
• Geometry-dependent skin effect and anisotropic Bloch oscillations in a non-Hermitian optical lattice
• Filling up complex spectral regions through non-Hermitian disordered chains
• Real-space topological localizer index to fully characterize the dislocation skin effect
• Magnetic Flux Response of Non-Hermitian Topological Phases
• Nonlinear Hall effects with an exceptional ring
• Exceptional second-order topological insulators
• Topological and fractal defect states in non-Hermitian lattices
• Experimentally Probing Non-Hermitian Spectral Transition and Eigenstate Skewness
• Fragile dislocation modes in obstructed atomic topological phases
• Algebraic States in Continuum in $d>1$ Dimensional Non-Hermitian Systems