Magneto-optical Kerr effect in spin split two-dimensional massive Dirac materials

Gonçalo Catarina, Nuno M R Peres, Joaquín Fernández-Rossier
2020 2D Materials  
Switch effect for spin-valley electrons in monolayer WSe2 structures subjected to optical field and Fermi velocity barrier X.-J. Hao et al -Magneto-optical response of chromium trihalide monolayers: chemical trends Alejandro Molina-Sánchez et al -This content was downloaded from IP address 193.145.230.254 on 30/10/2020 at 10:30 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
more » ... 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.
doi:10.1088/2053-1583/ab6781 fatcat:3lcc35v6mbetxed3qfnj26apsa