Electric-field modulation of linear dichroism and Faraday rotation in few-layer phosphorene. (21st December 2018)

• Record Type: Journal Article
• Authors: Li, L L; Partoens, B; Xu, W; Peeters, F M
• Is Part Of: 2D materials. Volume 6:Number 1(2019)
• Publication Date: 2018-12-21
• Subjects: few-layer phosphorene -- optical conductivity -- linear dichroism -- Faraday rotation -- tight-binding method -- self-consistent calculation; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aaf47f
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Electro-optical modulators, which use an electric voltage (or an electric field) to modulate a beam of light, are essential elements in present-day telecommunication devices. Using a self-consistent tight-binding approach combined with the standard Kubo formula, we show that the optical conductivity and the linear dichroism of few-layer phosphorene can be modulated by a perpendicular electric field. We find that the field-induced charge screening plays a significant role in modulating the optical conductivity and the linear dichroism. Distinct absorption peaks are induced in the conductivity spectrum due to the strong quantum confinement along the out-of-plane direction and to the field-induced forbidden-to-allowed transitions. The field modulation of the linear dichroism becomes more pronounced with increasing number of phosphorene layers. We also show that the Faraday rotation is present in few-layer phosphorene even in the absence of an external magnetic field. This optical Hall effect is induced by the reduced lattice symmetry of few-layer phosphorene. The Faraday rotation is greatly influenced by the field-induced charge screening and is strongly dependent on the strength of perpendicular electric field and on the number of phosphorene layers.