Topological gap states of semiconducting armchair graphene ribbons

Abstract

In semiconducting armchair graphene ribbons a chiral lattice deformation can induce pairs of topological gap states with opposite energies. Near the critical value of the deformation potential these kink and antikink states become almost degenerate with zero energy and have a fractional charge one-half. Such a semiconducting armchair ribbon represents a one-dimensional topological insulator with nearly zero energy end states. Using data collapse of numerical results we find that the shape of the kink displays an anomalous power-law dependence on the width of the local lattice deformation. We suggest that these gap states may be probed in optical measurements. However, "metallic" armchair graphene ribbons with a gap induced by many-electron interactions have no gap states and are not topological insulators.

4 pages, 3 figures

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Cited by in corpus (3)

• Soliton fractional charges in graphene nanoribbon and polyacetylene: similarities and differences
• Topological end states and Zak phase of rectangular armchair ribbon
• Gap states and edge properties of rectangular graphene quantum dot in staggered potential