title: Landau-Zener Bloch Oscillations with Perturbed Flat Bands.
abstract: Sinusoidal Bloch oscillations appear in band structures exposed to external fields. Landau-Zener (LZ) tunneling between different bands is usually a counteracting effect limiting Bloch oscillations. Here we consider a flat band network with two dispersive and one flat band, e.g., for ultracold atoms and optical waveguide networks. Using external synthetic gauge and gravitational fields we obtain a perturbed yet gapless band structure with almost flat parts. The resulting Bloch oscillations consist of two parts-a fast scan through the nonflat part of the dispersion structure, and an almost complete halt for substantial time when the atomic or photonic wave packet is trapped in the original flat band part of the unperturbed spectrum, made possible due to LZ tunneling.
authors.affiliation: Physics Department, Tbilisi State University, Chavchavadze 3, 0128 Tbilisi, Georgia.|Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34051, South Korea.
authors.forename: Ramaz
authors.initials: R
authors.lastname: Khomeriki
authors.affiliation: Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34051, South Korea.|New Zealand Institute for Advanced Study, Centre for Theoretical Chemistry & Physics, Massey University, Auckland 0745, New Zealand.
authors.forename: Sergej
authors.initials: S
authors.lastname: Flach