Photoluminescence and ultrafast spectroscopy on GaAs quantum wells close to a Ga(Mn)As layer

We present a study of nonmagnetic GaAs quantum wells (QWs) embedded in AlGaAs barriers close to a Ga(Mn)As layer. The photoluminescence (PL) spectra of QWs close (3 – 10 nm) to the Ga(Mn)As layer show a pronounced broadening and quenching of the PL. This may be due to diffusion of Mn ions into the QW during growth. Employing time‐resolved Faraday rotation measurements, we observe that the spin lifetime in the QW, separated by 10 nm from the Ga(Mn)As layer, is increased by a factor of 3, as compared to a control well, at a distance of 122 nm. However, in the measured g factors we see no influence of the Mn.