Quantum spin transport to semiconductor quantum dots through superlattice

Abstract

Spin transport properties from the GaAs/AlGaAs superlattice (SL) to InGaAs quantum dots (QDs) are studied by circularly polarized time-resolved photoluminescence spectroscopy of QD excited states with the selective excitation of SL miniband states. For the SL with a thinner barrier, we observe an effective carrier transport in SL owing to the stronger overlap of wavefunctions of adjacent quantum wells and a simultaneous highly efficient carrier injection into QDs. Moreover, the SL with a thinner barrier demonstrates a quantum spin transport to QDs maintaining high spin polarization during the transport process.