Optically detected magnetic resonance of photoexcited electrons in (In,Al)As/AlAs quantum dots with indirect band gap and type-I band alignment

Abstract

Optically detected magnetic resonance (ODMR) is measured for photoexcited electrons in (In,Al)As/AlAs quantum dots having an indirect band gap and a type-I band alignment. A sharp ODMR resonance corresponding to a $g$ factor of $1.97\ifmmode\pm\else\textpm\fi{}0.02$ is identified, associated with $X$-valley electrons. Its variation with optical transition energy allows us to distinguish between the spectral regions of direct and indirect QDs, which is in good agreement with the results on exciton recombination dynamics.