Spatial Offset of Excited States in Non-Hermitian Lattices

TL;DR

This paper explores how non-Hermitian lattices cause unique spatial shifts and wave packet formations of light, enabling optical control without structural changes, with potential applications in photonics.

Contribution

It demonstrates the spatial offset behavior of excited states in non-Hermitian lattices and introduces a geometric control mechanism for optical steering.

Findings

Excited states exhibit spatial displacement in non-Hermitian lattices.

Two-dimensional lattices form V-shaped wave packets with tunable orientation.

Optical steering achieved without structural modifications.

Abstract

We investigate the behavior of light-wave packets injected into non-Hermitian microcavity lattices under highly dissipative conditions. While all eigenstates of the lattice exhibit exponential decay, a specifically excited state maintains coherent propagation. In a one-dimensional lattice, this state undergoes a spatial displacement shift away from the injection position, which is a fundamental property of non-Hermitian systems with a point gap when the spectrum encircles a finite region in the complex plane. Extending such a shift to two-dimensional lattices reveals a geometrically anomalous V-shaped wave packet formation with orientation-tunable arms. Notably, this geometric control mechanism enables all-optical steering of non-Hermitian photonic states without requiring structural modifications.