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Tight-binding approach to uniaxial strain in graphene

2009; American Physical Society; Volume: 80; Issue: 4 Linguagem: Inglês

10.1103/physrevb.80.045401

1550-235X

Vitor M. Pereira, A. H. Castro Neto, N. M. R. Peres,

Topological Materials and Phenomena

We analyze the effect of tensional strain in the electronic structure of graphene. In the absence of electron-electron interactions, within linear elasticity theory, and a tight-binding approach, we observe that strain can generate a bulk spectral gap. However, this gap is critical, requiring threshold deformations in excess of 20% and only along preferred directions with respect to the underlying lattice. The gapless Dirac spectrum is robust for small and moderate deformations and the gap appears as a consequence of the merging of the two inequivalent Dirac points only under considerable deformations of the lattice. We discuss how strain-induced anisotropy and local deformations can be used as a means to affect transport characteristics and pinch off current flow in graphene devices.