title: Tight-binding electrons on triangular and kagomé lattices under staggered modulated magnetic fields: quantum Hall effects and Hofstadter butterflies.
abstract: We consider the tight-binding models of electrons on a two-dimensional triangular lattice and kagomé lattice under staggered modulated magnetic fields. Such fields have two components: a uniform-flux part with strength φ, and a staggered-flux part with strength Δφ. Various properties of the Hall conductances and Hofstadter butterflies are studied. When φ is fixed, variation of Δφ leads to the quantum Hall transitions and Chern numbers of Landau subbands being redistributed between neighboring pairs. The energy spectra with nonzero Δφs have similar fractal structures but quite different energy gaps compared with the original Hofstadter butterflies of Δφ = 0. Moreover, the fan-like structure of Landau levels in the low magnetic field region is also modified appreciably by Δφ.
authors: Center for Statistical and Theoretical Condensed Matter Physics, and Department of Physics, Zhejiang Normal University, Jinhua 321004, People's Republic of China.
authors: Juan
authors: J
authors: Li
authors: Yi-Fei
authors: YF
authors: Wang
authors: Chang-De
authors: CD
authors: Gong