Year: 2020
Type: article
Abstract: Two-dimensional (2D) massive Dirac electrons possess a finite Berry curvature, with Chern number 1/2, that entails both a quantized dc Hall response and a subgap full-quarter Kerr rotation. The observation of these effects in 2D massive Dirac materials such as gapped graphene, hexagonal boron nitride or transition metal dichalcogenides (TMDs) is obscured by the fact that Dirac cones come in pairs with opposite sign Berry curvatures, leading to a vanishing Chern number. Here, we show that the presence of spin–orbit interactions, combined with an exchange spin splitting induced either by diluted magnetic impurities or by proximity to a ferromagnetic insulator, gives origin to a net magneto-optical Kerr effect in such systems. We focus on the case of TMD monolayers and study the dependence of Kerr rotation on frequency and exchange spin splitting. The role of the substrate is included in the theory and found to critically affect the results. Our calculations indicate that state-of-the-art magneto-optical Kerr spectroscopy can detect a single magnetic impurity in diluted magnetic TMDs.
Source: 2D Materials
Authors: G Catarina, N M R Peres, J Fernández-Rossier
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,895
Awards: G1274295419, G1297482482, G1516346500, G1763632427, Novo: Correlated electronic phases in low-dimensional materials. Inicial: Emergent correlated electronic phases in van der Waals heterostructures, G3119009491, G3215429724, G323769159, Grafeno funcionalizado para tecnologias quânticas, G3724492130, G3840324753, G3891694003, G3991938951, G4627546747, G5224927334, G5454278309, Graphene Flagship Core Project 2, G6193525563, Desenvolver dispositivos óticas ultrarrápidos aproveitando as propriedades eletrónicas extraordinárias de materiais cristalinos 2D, G7271739000, G7713038420, Semicondutores magnéticos bidimensionais, Centro de Física das Universidades do Minho e do Porto, G8945308682
OpenAlex ID: W2997365702