# Tuning the Effective PT-Phase of Plasmonic Eigenmodes

## TL;DR

This paper experimentally demonstrates a PT-phase transition in a hybrid plasmonic-dielectric waveguide, revealing how eigenmode interactions change at the exceptional point, opening new avenues for tunable non-Hermitian plasmonic devices.

## Contribution

It presents the first experimental observation of an effective PT-phase transition in a plasmonic system through the exceptional point.

## Key findings

- Observation of PT-phase transition via exceptional point
- Eigenmode interaction changes with environmental refractive index
- Extension of non-Hermitian physics design in plasmonics

## Abstract

We experimentally observe an effective PT-phase transition through the exceptional point in a hybrid plasmonic-dielectric waveguide system. Transmission experiments reveal fundamental changes in the underlying Eigenmode interactions as the environmental refractive index is tuned, which can be unambiguously attributed to a crossing through the plasmonic exceptional point. These results extend the design opportunities for tuneable non-Hermitian physics to plasmonic systems.