Subskin modes in a nonlinear non-Hermitian system

TL;DR

This paper introduces subskin modes in nonlinear non-Hermitian systems, which localize below the edges and are limited in number, revealing new phenomena and potential applications distinct from traditional skin modes.

Contribution

It uncovers the existence of subskin modes in nonlinear non-Hermitian systems and explains how nonlinear interactions enable their formation under specific conditions.

Findings

Subskin modes localize below the system's edge.

Nonlinear interactions enable subskin modes beyond linear restrictions.

Potential applications for subskin modes in non-Hermitian systems.

Abstract

Subskin modes are distinct from conventional skin modes as they localize not at the system's edge but rather below the edge. Unlike skin modes, where a substantial number of them can accumulate at the boundaries of a system due to the non-Hermitian skin effect, subskin modes are typically limited to one or a few and emerge only when the size of the system and the couplings are related in a very specific way. The nonlinear interaction can lift the restrictions on the couplings for the formation of these modes. The findings reveal the potential of subskin modes for practical applications and new research in non-Hermitian systems.