CdSe colloidal nanoplatelets are studied by spin-flip Raman scattering in magnetic fields up to 5 T. We find pronounced Raman lines shifted from the excitation laser energy by an electron Zeeman splitting. Their polarization selection rules correspond to those expected for scattering mediated by excitons interacting with resident electrons. Surprisingly, Raman signals shifted by twice the electron Zeeman splitting are also observed. The theoretical analysis and experimental dependencies show that the mechanism responsible for the double flip involves two resident electrons interacting with a photoexcited exciton. Effects related to various orientations of the nanoplatelets in the ensemble and different orientations of the magnetic field are analyzed.
@article{arxiv.1911.01725,
title = {Single and double electron spin-flip Raman scattering in CdSe colloidal nanoplatelets},
author = {Dennis Kudlacik and Victor F. Sapega and Dmitri R. Yakovlev and Ina V. Kalitukha and Elena V. Shornikova and Anna V. Rodina and Eugeniius L. Ivchenko and Grigorii S. Dimitriev and Michel Nasilowski and Benoit Dubertret and Manfred Bayer},
journal= {arXiv preprint arXiv:1911.01725},
year = {2020}
}