Black phosphorus exhibits a high degree of band anisotropy. However, we found that its in-plane static screening remains relatively isotropic for momenta relevant to elastic long-range scattering processes. On the other hand, the collective electronic excitations in the system exhibit a strong anisotropy. Band non-parabolicity leads to a plasmon frequency which scales as nβ, where n is the carrier concentration, and β<21. Screening and charge distribution in the out-of-plane direction are also studied using a non-linear Thomas-Fermi model.
@article{arxiv.1404.4035,
title = {Plasmons and screening in monolayer and multilayer black phosphorus},
author = {Tony Low and Rafael Roldán and Han Wang and Fengnian Xia and Phaedon Avouris and Luis Martín Moreno and Francisco Guinea},
journal= {arXiv preprint arXiv:1404.4035},
year = {2014}
}