Black phosphorus exhibits a high degree of band anisotropy. However, we find 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 nonparabolicity, due to interband couplings, leads to a plasmon frequency which scales as n β , where n is the carrier concentration, and β < 1 2 . Screening and charge distribution in the out-of-plane direction are also studied using a nonlinear Thomas-Fermi model.

We experimentally demonstrate a broadband enhancement of the light absorption in graphene over the whole visible spectrum. This enhanced absorption is obtained in a multilayer structure by using an Attenuated Total Reflectance (ATR) configuration and it is explained in terms of coherent absorption arising from interference and dissipation. The interference mechanism leading to the phenomenon of coherent absorption allows for its precise control by varying the refractive index and/or thickness of the medium surrounding the graphene.

Highlights Three important indicators of fatness (body mass index, wait to hip ratio, and fat mass index) show a significant and positive association with a powerful indicator of cardiometabolic risk in adolescents. Cardiorespiratory fitness (CRF) shows a significant and inverse relationship with the cardiometabolic risk of adolescents. To date, the mediating role of CRF in the relationship of fatness and cardiometabolic risk in adolescents has not been demonstrated. The CRF is capable of partially mediating (approximately 10%) the association of fatness and cardiometabolic risk. Decreasing fatness indicators and increasing CRF are necessary to improve adolescent cardiometabolic health.