Observation of a Dirac point in microwave experiments with a photonic crystal modeling graphene

TL;DR

This study demonstrates the observation of a Dirac point in a microwave photonic crystal, mimicking graphene's electronic properties, through transmission and reflection spectra measurements.

Contribution

It provides experimental evidence of Dirac points in a microwave photonic crystal, modeling relativistic fermions similar to graphene.

Findings

Clear Dirac point observed in spectra

Spectra resemble graphene conductance measurements

Photonic crystal mimics graphene's electronic properties

Abstract

We present measurements of transmission and reflection spectra of a microwave photonic crystal composed of 874 metallic cylinders arranged in a triangular lattice. The spectra show clear evidence of a Dirac point, a characteristic of a spectrum of relativistic massless fermions. In fact, Dirac points are a peculiar property of the electronic band structure of graphene, whose properties consequently can be described by the relativistic Dirac equation. In the vicinity of the Dirac point, the measured reflection spectra resemble those obtained by conductance measurements in scanning tunneling microscopy of graphene flakes.