Ferromagnetic Fe-doped InAs quantum dots with high Curie temperature

Abstract

We report the structural and magnetic properties of Fe-doped InAs quantum dots (QDs) grown on GaAs (001) substrates by molecular beam epitaxy. The size and distribution of the QDs are revealed by atomic force microscopy and characterized by scanning tunnelling electron microscopy, which confirms zinc-blende crystal structure. Magnetometry measurements show the presence of ferromagnetism in the QDs and a very high Curie temperature (>300 K). Magnetic circular dichroism spectra of these QDs exhibit a single peak at 900–1000 nm. These results suggest that the Fe-doped InAs QDs are promising for spintronics device applications such as spin-light emitting diodes operating at room temparture.