Resonant inelastic x-ray scattering from electronic excitations in -RuCl₃ nanolayers

We present Ru L-3-edge resonant inelastic x-ray scattering (RIXS) measurements of spin-orbit and d-d excitations in exfoliated nanolayers of the Kitaev spin-liquid candidate RuCl3. Whereas the spin-orbit excitations are independent of thickness, we observe a pronounced redshift and broadening of the d-d excitations in layers with thicknesses below similar to 7 nm. Aided by model calculations, we attribute these effects to distortions of the RuCl6 octahedra near the surface. Our study paves the way towards RIXS investigations of electronic excitations in various other two-dimensional materials and heterostructures.