Skin mode tunability and self-healing effect in photonic Floquet lattices

TL;DR

This paper proposes a scheme to realize the self-healing effect of non-Hermitian skin modes in photonic Floquet lattices by exploiting skin mode tunability, enabling spectral control through remote boundary potentials.

Contribution

It introduces a novel method to achieve skin mode self-healing in photonic lattices by tuning skin modes via boundary potentials, expanding non-Hermitian wave control techniques.

Findings

Demonstrated sensitivity of skin modes to remote boundary potentials.

Achieved broad-range spectral control in an array of 100 coupled waveguides.

Proposed experimentally feasible scheme for observing SHE in photonic systems.

Abstract

Non-Hermitian systems host exotic phenomena absent in their Hermitian counterparts, including the recently predicted self-healing effect (SHE) of non-Hermitian skin modes. To date, the SHE of skin modes in non-Hermitian systems has not been observed experimentally. Here we propose a feasible scheme to realize SHE in photonic Floquet lattices by exploiting skin mode tunability (SMT), a mechanism in which the spectrum of skin modes localized at one boundary can be tuned via a potential applied at the opposite boundary. Such tunability arises from the non-Hermitian biorthogonality of the eigenstates. We demonstrate that a certain skin mode is exceptionally sensitive to remote-boundary potentials in an array of $100$ coupled helical waveguides, allowing broad-range spectral control and the generation of SHE with experimentally accessible parameters. Our results establish a general framework for engineering skin modes via local perturbations, thereby expanding the toolbox for non-Hermitian wave control.