On the propagation of Dirac fermions in graphene with the strain-induced inhomogeneous Fermi velocity

TL;DR

This paper investigates how mechanical deformations in graphene, causing inhomogeneous Fermi velocities, can manipulate Dirac fermion wave packets, enabling waveguiding and focusing effects with potential applications in valleytronics.

Contribution

It introduces a theoretical framework for understanding wave packet propagation in strained graphene with inhomogeneous Fermi velocities, highlighting novel waveguiding mechanisms.

Findings

Mechanical deformations cause wave packet deflection and focusing.

Inhomogeneous strains can create valley-polarized waveguides.

Analogy with reflectionless quantum systems enhances understanding.

Abstract

We consider systems described by the two-dimensional Dirac equation where the Fermi velocity is inhomogeneous as a consequence of mechanical deformations. We show that the mechanical deformations can lead to deflection and focusing of the wave packets. The analogy with known reflectionless quantum systems is pointed out. Furthermore, with the use of the qualitative spectral analysis, we discuss how inhomogeneous strains can be used to create waveguides for valley polarized transport of partially dispersionless wave packets.