2021/06/30 by Balaganchi A. Bhargava, Ion Cosma Fulga, Jeroen van den Brink +1 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.104.l241402
published as Phys. Rev. B 104, L241402 (2021) · 6+4 pages, 2+2 figures
arxiv created 2021/12/15 · arxiv updated 2021/12/16
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 Z2 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.