Transport in Sawtooth photonic lattices
  We investigate, theoretically and experimentally, a photonic realization of a Sawtooth lattice. This special lattice exhibits two spectral bands, with one of them experiencing a complete collapse to a highly degenerate flat band for a special set of inter-site coupling constants. We report the ob- servation of different transport regimes, including strong transport inhibition due to the appearance of the non-diffractive flat band. Moreover, we excite localized Shockley surfaces states, residing in the gap between the two linear bands. 
Steffen Weimann, Luis Morales-Inostroza, Basti\'an Real, Camilo   Cantillano, Alexander Szameit, and Rodrigo A. Vicencio
physics.optics