Frank Schindler (Imperial College, London): “Hermitian Bulk — Non-Hermitian Boundary Correspondence”

“Hermitian Bulk — Non-Hermitian Boundary Correspondence”
Talk presented at Condensed Matter Physicsin the City 2023, London, 12. July 2023.

Abstract: Non-Hermitian topology offers a fresh perspective on open quantum systems, but identifying suitable physical realizations remains a challenge. In my talk, I will demonstrate that the lossless edge states of Hermitian topological insulators acquire nontrivial non-Hermitian topological invariants upon exposure to minor perturbations. This discovery expands the range of potential materials for non-Hermitian topology to encompass all known topological insulators. I will provide a comprehensive characterization of the emergent higher-order non-Hermitian skin effects and edge states, which act as distinctive experimental signatures for the correspondence between Hermitian and non-Hermitian topology.