Bloch-Zener oscillations in ribbon-shaped optical lattices
Max-Planck-Institut für Physik Komplexer Systeme - Nöthnitzer Str. 38, D-01187 Dresden, Germany, EU
2 Friedrich Schiller University, Institute of Condensed Matter Theory and Optics - D-07743 Jena, Germany, EU
3 Departamento de Física, Facultad de Física, Pontificia Universidad Católica de Chile Casilla 306, Santiago 22, Chile
Accepted: 8 November 2011
We theoretically study the topological effects of zigzag-edged ribbons on the motion of collective excitations. Pristine geometries resembling those of narrow graphene nanoribbons as well as edge structures with dangling bonds are considered with the help of photonic lattices and/or Bose-Einstein condensates trapped in deep optical lattices. We observe an irrational fractionalization of the excitations when moving under the action of an external field. This effect is discussed in terms of the interband dynamics associated with the systems in consideration.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 52.35.Mw – Nonlinear phenomena: waves, wave propagation, and other interactions (including parametric effects, mode coupling, ponderomotive effects, etc.) / 05.60.Gg – Quantum transport
© EPLA, 2011