Non-Hermitian effective medium theory and complex Dirac-like cones

In this work, we propose a non-Hermitian effective medium theory to interpret the spawning rings of exceptional points out of the Dirac cones in the band structures of photonic crystals with loss/gain. Based on this theory, we predict and demonstrate two unique types of band dispersions of fully pas...

Full description

Saved in:
Bibliographic Details
Published in:Optics express 2021-05, Vol.29 (10), p.14345-14353
Main Authors: Luo, Liyou, Shao, Yuming, Li, Jensen, Fan, Renhao, Peng, Ruwen, Wang, Mu, Luo, Jie, Lai, Yun
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this work, we propose a non-Hermitian effective medium theory to interpret the spawning rings of exceptional points out of the Dirac cones in the band structures of photonic crystals with loss/gain. Based on this theory, we predict and demonstrate two unique types of band dispersions of fully passive photonic crystals. In one type, the exceptional ring shrinks into a complex Dirac point associated with a complex Dirac-like cone. In the other type, a point of quadratic degeneracy is realized in the imaginary frequency spectrum. Our theory provides a unified picture for the exceptional points in effective media and gives rise to novel concepts like complex Dirac-like cones in non-Hermitian photonics.
ISSN:1094-4087
1094-4087
DOI:10.1364/OE.425862