Giant magneto-optical Raman effect in a layered transition metal compound

Significance Raman scattering is a powerful technique to probe optical phonons in solids. It usually involves an electron-mediated three-step process, involving photon–electron, electron–phonon, and electron–photon interactions. In principle, manipulating electrons, for instance by applying a magnetic field, should affect Raman phonon intensity, yet there is no direct experimental measurement to demonstrate this. In this work we report the first realization to our knowledge of the idea in a prototype material, MoS 2 . From monolayer and bilayer to bulk MoS 2 we observe a dramatic modification of Raman phonon intensity induced by magnetic field. Such a giant magneto-optical effect appearing at a monoatomic layer level and its technological implications for magnetic-optical devices should inspire a new branch of inelastic light scattering.