# Granular Graphene: direct observation of zigzag and armchair edge waves

## TL;DR

This paper introduces a mechanical granular graphene model using steel beads, demonstrating Dirac points and edge wave phenomena, providing a new platform for studying advanced wave behaviors.

## Contribution

It presents the first experimental realization of granular graphene with observed Dirac points and edge wave dynamics, highlighting its potential for exploring topological and nonlinear wave phenomena.

## Key findings

- Observation of Dirac points in granular graphene
- Experimental evidence of edge wave propagation and turning effects
- Granular graphene as a platform for novel wave phenomena

## Abstract

We propose a mechanical granular graphene obtained by replacing the carbon atoms with macroscopic spherical stainless steel beads in contact. The experimental measured dispersion relation is presented, in conjunction with evidence of the Dirac points. In addition, wave propagation along the zigzag and a robust turning effect of edge waves from the zigzag to the armchair boundary is experimentally revealed, even in the absence of a full band gap for bulk modes. Our work shows that mechanical granular graphene can serve as an excellent experimental platform to study novel Dirac, topological and nonlinear wave phenomena.