Resonant modes in strain-induced graphene superlattices

TL;DR

This paper investigates how strain-induced superlattices in graphene affect electron tunneling, revealing new resonant modes and bound states that could enable mode filtering for electronic transport.

Contribution

It provides an analytical study of resonant tunneling modes and bound state spectra in strain-engineered graphene superlattices, including effects of Dirac point shifts and anisotropic Fermi velocities.

Findings

Identification of additional resonant tunneling modes in periodic strain structures

Analysis of bound state spectra as a function of energy and momentum

Strain superlattices can act as effective mode filters for graphene transport

Abstract

We study tunneling across a strain-induced superlattice in graphene. In studying the effect of applied strain on the low-lying Dirac-like spectrum, both a shift of the Dirac points in reciprocal space, and a deformation of the Dirac cones is explicitly considered. The latter corresponds to an anisotropic, possibly non-uniform, Fermi velocity. Along with the modes with unit transmission usually found across a single barrier, we analytically find additional resonant modes when considering a periodic structure of several strain-induced barriers. We also study the band-like spectrum of bound states, as a function of conserved energy and transverse momentum. Such a strain-induced superlattice may thus effectively work as a mode filter for transport in graphene.