Kubo conductivity in phosphorene

Abstract

Electrical conductivity in phosphorene is investigated within the linear response theory. We find that phosphorene shows signatures of asymmetry in its transport properties, inherited from the anisotropic band structure of that system. It is shown that the Dirac fermions in phosphorene exhibit enhanced electrical conductivity around the edges of conduction and valence bands, where the conductivity peak corresponding to the conduction band is larger than the one associated with the valence band, hallmark of anisotropic band structure of phosphorene. The separation between the two conductivity peaks is on the order of the band gap. In addition, the electrical conductivity shifts in the negative region of the chemical potential, reflecting anisotropy in the energy spectrum inherited from the lack of chiral symmetry in the Hamiltonian of the system. We also find that the electrical conductivity strongly depends on temperature of the system. Interestingly, the separation between the conductivity peaks can be tuned by an applied electric field which can vary the band gap induced by spin–orbit interaction.