Lattice-corrected strain-induced vector potentials in graphene

TL;DR

This paper refines the theoretical understanding of strain-induced vector potentials in graphene by including lattice deformation effects, which are crucial for accurately modeling pseudomagnetic fields in inhomogeneously strained graphene.

Contribution

It extends the standard model by explicitly incorporating lattice deformations, revealing their importance in accurately determining pseudovector potentials and pseudomagnetic fields.

Findings

Lattice deformations significantly modify strain-induced vector potentials.

Corrections are linear in strain and differ at each Dirac point.

Implications for designing strain profiles to control electronic properties.

Abstract

The electronic implications of strain in graphene can be captured at low energies by means of pseudovector potentials which can give rise to pseudomagnetic fields. These strain-induced vector potentials arise from the local perturbation to the electronic hopping amplitudes in a tight-binding framework. Here we complete the standard description of the strain-induced vector potential, which accounts only for the hopping perturbation, with the explicit inclusion of the lattice deformations or, equivalently, the deformation of the Brillouin zone. These corrections are linear in strain and are different at each of the strained, inequivalent Dirac points, and hence are equally necessary to identify the precise magnitude of the vector potential. This effect can be relevant in scenarios of inhomogeneous strain profiles, where electronic motion depends on the amount of overlap among the local Fermi surfaces. In particular, it affects the pseudomagnetic field distribution induced by inhomogeneous strain configurations, and can lead to new opportunities in tailoring the optimal strain fields for certain desired functionalities.