Generalizing the Fermi velocity of strained graphene from uniform to nonuniform strain
Abstract
The relevance of the strain-induced Dirac point shift to obtain the appropriate anisotropic Fermi velocity of strained graphene is demonstrated. Then a critical revision of the available effective Dirac Hamiltonians is made by studying in detail the limiting case of a uniform strain. An effective Dirac Hamiltonian for nonuniform strain is thus reported, which takes into account all strain-induced effects: changes in the nearest-neighbor hopping parameters, the reciprocal lattice deformation and the true shift of the Dirac point. Pseudomagnetic fields are thus explained by means of position-dependent Dirac cones, whereas complex gauge fields appear as a consequence of a position-dependent Fermi velocity. Also, position-dependent Fermi velocity effects on the spinor wavefunction are considered for interesting cases of deformations such as flexural modes.
Keywords
Cite
@article{arxiv.1404.2619,
title = {Generalizing the Fermi velocity of strained graphene from uniform to nonuniform strain},
author = {M. Oliva-Leyva and Gerardo G. Naumis},
journal= {arXiv preprint arXiv:1404.2619},
year = {2015}
}