Magnetoelectronic properties of multilayer black phosphorus

We examine the electronic properties of two-dimensional electron gas in black phosphorus multilayers in the presence of a perpendicular magnetic field, highlighting the role of in-plane anisotropy on various experimental quantities such as ac magnetoconductivity, screening, and magnetoplasmons. We find that resonant structures in the ac conductivity exhibits a redshift with increasing doping due to interband coupling gamma. This arises from an extra correction term in the Landau energy spectrum proportional to n(2)gamma(2) (n is Landau index), up to second order in gamma. We found also that Coulomb interaction leads to highly anisotropic magnetoexcitons.