Transport of <i>p</i> – <i>n</i> junction in complex honeycomb lattice

Abstract

We investigate electron transport through the p–n junction of a complex honeycomb (CHC) lattice under a vertical magnetic field, where m atoms are added to each side of the hexagonal honeycomb lattice (with m=0 corresponding to graphene). Using the tight-binding model and Landauer–Bu¨ttiker formalism, and non-equilibrium Green’s function method, we study the conductance of clean and disordered CHC lattices. For clean CHC lattices, equidistant plateaus appear in the n–n junctions. The conductance plateau values of m=0 and m=2 lattices are (2n+1)⋅2e2/h, while those for m=1 and m=3 lattices are n⋅2e2/h (n=0,1,2,…). In the p–n region, the partial conductance of the CHC lattice is caused by Klein tunneling, and the lattice conductance of m=1 and m=3 exhibits oscillations. For the disordered m=1 CHC lattice, a bidirectional conduction channel is formed near right lead energy ER=0. For CHC lattices with a magnetic field, disorder can enhance conductance, but the ideal plateau only exists within a certain range of disorder intensity.