Antiferromagnetic coupling in CdSe/ZnMnSe quantum dot structures

• 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 σ− circular polarization of photoluminescence from the CdSe QDs is observed under optical excitation at the σ+-active 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.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

antiferromagnetic materials

cadmium compounds

excitons

II-VI semiconductors

magnetic epitaxial layers

magnetic multilayers

magneto-optical effects

manganese compounds

photoluminescence

semiconductor epitaxial layers

semiconductor quantum dots

semimagnetic semiconductors

time resolved spectra

wide band gap semiconductors

zinc compounds

Publication and Content Type

ref (subject category)

art (subject category)