Raman spectroscopy of shear and layer breathing modes in multilayer MoS2

We study by Raman scattering the shear and layer breathing modes in multilayer MoS2. These are identified by polarization measurements and symmetry analysis. Their positions change significantly with the number of layers, with different scaling for odd and even layers. A chain model can explain the results, with general applicability to any layered material, allowing a reliable diagnostic of their thickness.