Soliton Trap in Strained Graphene Nanoribbons

TL;DR

This paper demonstrates that strain in graphene nanoribbons can create topological solitons near the edges, which are zero-energy states connecting chiralities and could be observed experimentally.

Contribution

It applies chiral gauge theory to graphene to predict the existence of strain-induced topological solitons at nanoribbon boundaries.

Findings

Topological solitons exist near strained edges of graphene nanoribbons.

These solitons are zero-energy states connecting different chiralities.

The solitons are observable via scanning tunneling microscopy.

Abstract

The wavefunction of a massless fermion consists of two chiralities, left-handed and right-handed, which are eigenstates of the chiral operator. The theory of weak interactions of elementally particle physics is not symmetric about the two chiralities, and such a symmetry breaking theory is referred to as a chiral gauge theory. The chiral gauge theory can be applied to the massless Dirac particles of graphene. In this paper we show within the framework of the chiral gauge theory for graphene that a topological soliton exists near the boundary of a graphene nanoribbon in the presence of a strain. This soliton is a zero-energy state connecting two chiralities and is an elementally excitation transporting a pseudospin. The soliton should be observable by means of a scanning tunneling microscopy experiment.