Magneto-photoluminescence from single-quantum structures of diluted magnetic semiconductor fabricated by e-beam lithography

Micro-photoluminescence (PL) has been studied in magnetic fields for single quantum nanostructures, such as, a quantum wire (QWR) and dot (QD) of Zn1−x−yCdxMnySe diluted magnetic semiconductor (DMS), where the DMS nanostructures were fabricated by means of electron-beam lithography. The giant Zeeman shift of excitons in the DMS-QWRs with the widths less than 50 nm appears larger than that in a quantum well (QW), which can be attributed to suppression of the exciton diffusion into deeper local sites with less Mn-content. In addition, the DMS-QDs have successfully been fabricated. We show spin injection from the DMS to non-magnetic dots in a coupled QD structure. The spin injection is clearly shown by PL with the circular polarization degree up to 20% from the non-magnetic dot, which is higher than that of 11% in the case of coupled QW. Effects of exciton diffusion are also discussed in the dot structures.