Antiferromagnetic interaction in coupled CdSe/ZnMnSe quantum dot structures

作者：Dagnelund D^*; Ren Q J; Buyanova I A; Murayama A; Chen W M

来源：Applied Physics Letters, 2012, 101(5): 052405.

DOI：10.1063/1.4739852

Spin polarization of nonmagnetic CdSe quantum dots (QDs) coupled to adjacent ZnMnSe diluted magnetic semiconductor (DMS) is investigated by CW and time-resolved magneto-optical spectroscopy under tunable laser excitation. Efficient enhancement in the degree of sigma(-) circular polarization of photoluminescence from the CdSe QDs is observed under optical excitation at the sigma(+)-tactive exciton state of the DMS. The fact that the enhancement persists much longer than the exciton lifetime of the DMS rules out a role of the DMS excitons. A possible explanation is discussed in terms of antiferromagnetic coupling between the excitons in QDs and aligned Mn ions in DMS.

• 出版日期2012-7-30