# Chiral behaviour for three wave guides at an exceptional point of third order

## TL;DR

This paper investigates a matrix model of three coupled wave guides at a third-order exceptional point, revealing chiral eigenfunction behaviour that can be experimentally tested, advancing understanding of PT-symmetric systems.

## Contribution

It introduces a simple matrix model for three wave guides at a third-order exceptional point and demonstrates the chiral behaviour of eigenfunctions near this point.

## Key findings

- Eigenfunctions exhibit distinctive chiral behaviour near the exceptional point
- Chiral behaviour can be observed experimentally in realistic setups
- The model captures essential features of PT-symmetric three-wave guide systems

## Abstract

A simple matrix model that has been used to describe essential features of a PT symmetric set-up of three coupled wave guides is investigated. The emphasis of the study lies on the occurrence of an exceptional point of third order. It is demonstrated that the eigenfunctions in close vicinity of the exceptional point have a distinctive chiral behaviour. Using data describing realistic situations it is argued that such chiral behaviour can be tested experimentally.