Ferromagnetism in One Layer of Self-organized InMnAs Quantum Dots

Abstract

One layer of self-assembled InMnAs quantum dots with InGaAs barrier was grown on high-resistivity (100) p-type GaAs substrates by molecular beam epitaxy (MBE). A presence of ferromagnetic structure was confirmed in the InMnAs dilute magnetic quantum dots. The one layer of self-assembled InMnAs quantum dots was found to be semiconducting, and have ferromagnetic ordering with a Curie temperature, TC=80 K. It is likely that the ferromagnetic exchange coupling of sample with TC=80 K is hole-mediated resulting in Mn substituting Ge. PL emission spectra of InMnAs samples grown at temperature of 210°C and 285°C show that the interband transition peak centered at 1.31 eV comes from the InMnAs quantum dot.