Redistributing Chern numbers of Landau subbands: tight-binding electrons under staggered modulated magnetic fields.
We investigate the magnetotransport properties of electrons on a square lattice under a magnetic field with the alternate flux strength phi+/-Deltaphi in neighboring plaquettes. A new peculiar behavior of the Hall conductance has been found and is robust against weak disorder: if phi=(p/2N)2pi (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 +/-Ne2/h at critical fillings when Deltaphi is increased from 0 up to a critical value Deltaphi_{c}. This effect can be an experimental probe of the staggered-flux phase.
Wang
Yi-Fei
YF
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.
Gong
Chang-De
CD