Collapse of Landau level in semi-Dirac materials

Abstract: Two-dimensional semi-Dirac models describe a family of novel materials that have anisotropic dispersion with relativistic-type spectrum along one of the spatial directions and non-relativistic along another. In the present paper we perform a detailed analysis of Landau levels collapse for such models in perpendicular magnetic field and in-plane electric field by using semi-classical approach and tight-binding simulations. The anisotropic nature of semi-Dirac dispersion manifests itself in the possibility of Landau level collapse for only one of the electric field directions. In addition, the topological transition with merging Dirac cones has its own distinct features in Landau level collapse.