July 15, 2009 | Vitor M. Pereira and A. H. Castro Neto, N. M. R. Peres
The paper by Vitor M. Pereira and A. H. Castro Neto, along with N. M. R. Peres, explores the effect of uniaxial strain on the electronic structure of graphene using a tight-binding approach. They find that under linear elasticity theory and without electron-electron interactions, strain can generate a bulk spectral gap, but this gap is critical and requires deformations exceeding 20%. The gap appears when the two inequivalent Dirac points merge under significant lattice deformations, rather than due to a broken sublattice symmetry. Strain along the zig-zag direction is most effective in opening the gap, while deformations along the armchair direction do not induce a gap. The authors discuss how strain-induced anisotropy and local deformations can be used to affect transport characteristics and pinch off current flow in graphene devices. They also highlight the robustness of the gapless Dirac spectrum for small and moderate deformations, and the potential of local strain profiles to impact transport and electronic structure.The paper by Vitor M. Pereira and A. H. Castro Neto, along with N. M. R. Peres, explores the effect of uniaxial strain on the electronic structure of graphene using a tight-binding approach. They find that under linear elasticity theory and without electron-electron interactions, strain can generate a bulk spectral gap, but this gap is critical and requires deformations exceeding 20%. The gap appears when the two inequivalent Dirac points merge under significant lattice deformations, rather than due to a broken sublattice symmetry. Strain along the zig-zag direction is most effective in opening the gap, while deformations along the armchair direction do not induce a gap. The authors discuss how strain-induced anisotropy and local deformations can be used to affect transport characteristics and pinch off current flow in graphene devices. They also highlight the robustness of the gapless Dirac spectrum for small and moderate deformations, and the potential of local strain profiles to impact transport and electronic structure.