Band structures and contact points in phosphorene superlattice

We study the band structures and the associated contact points for a phosphorene superlattice made up of two periodic areas. We use the boundary conditions to extract an equation describing the dispersion relation after obtaining the eigen-wavefunctions. We show that energy transforms into linear behavior near contact points, and fermions move at different speeds along $x$- and $y$- directions. It was discovered that the periodic potential caused additional Dirac points, which we located in $k$-space by establishing their positions. We demonstrate that the barrier height and width can be used to adjust the energy gap and modify the contact points. It might be that our findings will be useful in the development of phosphorene-based electronic devices.