Gate tunable conductance anisotropy in bilayer black phosphorene

We have studied the conductance anisotropy of bilayer black phosphorene under chemical potential or external electric fields based on the non-equilibrium Green's function method. The results have shown that the chemical potential has a huge impact on the direction and magnitude of the conductance anisotropy of bilayer black phosphorene, which beyond those of monolayer. In addition, it is found that the interlayer coupling enhances the conductance anisotropy on the valence band maximum. Particularly, the conductance anisotropy can be greatly modulated by external electric field, and the direction of the maximum and minimum conductance can be even reversed by external electric field. The controllability between the interlayer coupling and the conductance anisotropy with external field is of interest to the field of nano-electronics and have some technical promise.