The polarization switching in nanoscale with an anisotropic 2D magnetic semiconductor

Here we present a proof-of-concept device demonstrating the feasibility to control the light polarization using the properties of the magnetic 2D materials. The studied structure consists of a diluted magnetic semiconductor quantum well and a thin layer of CrSBr. We show that by application of the external field we can switch the sign of the polarization of the emitted light. The theoretical modeling confirms that such a switching is a direct consequence of a colossal shift of the exciton lines observed in the high energy range of the CrSBr spectra. Owing to this mechanism, the full rotation of the polarization state can be realized in a layer as thin as few hundred nanometers.