Redistributing Chern numbers of Landau subbands: tight-binding electrons under staggered-modulated magnetic fields
Abstract
Description
We investigate the magneto-transport properties of electrons on a square lattice under a magnetic field with the alternate flux strength $ϕ\pmΔϕ$ in neighboring plaquettes. A new peculiar behavior of the Hall conductance has been found and is robust against weak disorder: if $ϕ={p\over{2N}}\times{2π}$ ($p$ and $2N$ are coprime integers) is fixed, the Chern numbers of Landau subbands will be redistributed between neighboring pairs and hence the total quantized Hall conductance exhibits a direct transition by $\pm{N}e^2/h$ at critical fillings when $Δϕ$ is increased from 0 up to a critical value $Δϕ_c$. This effect can be an experimental probe of the staggered-flux phase.
5 pages, 5 figures, 1 table
5 pages, 5 figures, 1 table