Non-Hermitian dynamical topological winding in photonic mesh lattices

TL;DR

This paper explores a novel form of topological winding in non-Hermitian photonic systems, where the mean survival time of optical pulses exhibits quantized, robust behavior due to dynamical evolution, opening new experimental avenues.

Contribution

It introduces a new class of dynamical topological phenomena in non-Hermitian photonic lattices based on pulse survival times, distinct from traditional band-structure topologies.

Findings

Mean survival time is quantized and robust against Hamiltonian changes.

Dynamical topological winding arises from system evolution, not static band properties.

Photonic mesh lattices can experimentally demonstrate these phenomena.

Abstract

Topological winding in non-Hermitian systems are generally associated to the Bloch band properties of lattice Hamiltonians. However, in certain non-Hermitian models topological winding naturally arise from the dynamical evolution of the system and related to a new form of geometric phase. Here we investigate dynamical topological winding in non-Hermitian photonic mesh lattices, where the mean survival time of an optical pulse circulating in coupled fiber loops is quantized and robust against Hamiltonian deformations. The suggested photonic model could provide an experimentally accessible platform for the observation of non-Hermitian dynamical topological windings.