Magneto-optical Kerr effect in two-dimensional diluted magnetic transition metal dichalcogenide semiconductors

In this talk, I will present a theory to model the Kerr angle for two-dimensional transition metal dichalcogenide semiconductors, such as MoS2, doped with a small density of magnetic atoms. The model Hamiltonian describes the band carriers within the effective gapped Dirac theory, accounting for spin-orbit and spin-valley coupling [1]. The magnetic impurities are described within a mean-field virtual crystal approximation, leading to a band-dependent spin splitting of the spectrum [2]. We find that the transverse optical susceptibility is non-zero, leading to a finite Kerr angle, when the exchange-induced splitting in the valence and conduction bands are different. We consider the case when there are no free carriers in the bands, as well as the n-doped and p-doped regimes.

[1] XIAO, D. et al. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Physical Review Letters, v. 108, n. 19, p. 196802, 2012.

[2] FERNáNDEZ-ROSSIER, J. et al. Coherently photoinduced ferromagnetism in diluted magnetic semiconductors. Physical Review Letters, v. 93, n. 12, p. 127201, 2004.