(color online) Left column: The weights of the wave packet P₊ and P_– versus time t. Rigth column: The projection of the initial wave packet on the Landau bands. Here we show the diffusion in the z direction for 4 kinds of initial packets on the xy plane. The last row is for a random pre-normalized initial packet, ψ⁰(x, y) = a + ib, with a and b are randomly chosen in [–0.5,0.5]. The results shown here are averaged over 1000 random configurations. The projections to the 0-th and ± 1st Landau levels are indicated in the right corner, while the projections on the other Landau levels are shown but not indicated explicitly.