The transverse magnetic surface plasmon in anisotropic black phosphorene

Abstract

Using the Kubo formalism, the intraband optical conductivity of black phosphorene (BP) with an anisotropic energy spectrum is obtained. The presence of BP in an infinite sandwich between two dielectric media supports the transverse magnetic (TM) BP surface plasmon polariton (SPP) wave. Thereby, the effective indices neff for TM BP SPP mode exhibits a linear relation with the incident frequency, which can be tuned by the chemical potential as well as by the dielectric medium surrounding the BP layer. The sublinear dependence of the reciprocal of neff on the chemical potential indicates the effective masses in the armchair and zigzag directions are dependent on the carrier wave vector. Moreover, the effective mass in the armchair direction is more dispersive. The anisotropic optoelectronic features in BP offer more tunability in the design and application of optoelectronic devices as an isotropic system like graphene.