Dynamic nuclear polarization in a self-assembled InAlAs quantum dot
Abstract
We present the signature for optical pumping of nuclear spins in a self-assembled InAlAs/AlGaAs quantum dot via the polarization-dependent energy shift of the excitonic emission. The energy shift is well known as Overhauser shift and has observed in a interface-fluctuation GaAs quantum dot. However, there has been no observation so far in a self-assembled QD, which is suitable for formation of vertically coupled QDs. We have demonstrated that the magnitude of the Overhauser shift was enhanced by the photo-injection of the highly-polarized electron and was controllable by the polarization of the excitation light. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)