Reversal of the chiral anomaly bulk states with periodically staggered potential

A chiral anomaly Landau level emerges when a Weyl semimetal is subjected to an external magnetic field. Recently, it was demonstrated that similar chiral anomaly bulk states exist within two-dimensional Dirac semimetals if proper boundary conditions are applied. The resulting chiral bulk states disperse linearly with the slope determined by a combination of the boundary condition and chirality of the Dirac cone, i.e., whether it is at $K$ or $K$\ensuremath{'} point. In this paper, we show that the slope (the sign of group velocity) near the $K$ and $K$\ensuremath{'} points can be reversed under a periodically staggered potential. We first analyze the parameter dependence of this phenomenon with a nearest-neighbor tight-binding model. Then, we give a semianalytical solution for the dispersion of the chiral anomaly bulk states. In the end, we provide a photonic crystal system and prove with full-wave simulations that such a phenomenon can indeed be observed.