Dilute magnetic impurity-induced effective phonon magnetic moment in Fe-doped monolayer MoS₂

The exciton-activated circularly polarized phonon has been demonstrated in monolayer MoS₂ and its large effective phonon magnetic moment can be interpreted using the orbital-phonon coupling model. Here, we investigate how magnetic impurity doping modifies the coupling between the orbital transition and the circularly polarized phonon. Using helicity-resolved magneto Raman spectroscopy, we find that substitutional Fe atoms introduce localized magnetic moments and an additional band beneath the conduction band. The resulting orbital transition between the Mo 4d and Fe 3d states hybridizes with the E” phonon mode, producing an additional doubly degenerate mode at 283 cm^-1. In the presence of an external magnetic field, this hybridized mode exhibits large Zeeman splitting corresponding to an effective phonon magnetic moment of 2.8 μB, comparable to that of undoped MoS₂. Our results establish dilute magnetic impurity doping as a feasible method to tune the effective phonon magnetic moment in two-dimensional semiconductors.