AG Mathematische Physik: Lars Koekenbier (FAU): Spectral localizer for line-gapped non-hermitian systems

Lars Koekenbier (FAU)

Spectral localizer for line-gapped non-hermitian systems

Abstract:
Short-ranged and line-gapped non-hermitian Hamiltonians have strong topological
invariants given by an index of an associated Fredholm operator. It is shown how
these invariants can be accessed via the signature of a suitable spectral
localizer. This numerical technique is implemented in an example with relevance
to the design of topological photonic systems, such as topological lasers.