Magnetotransport properties of GaMnAs/ZnMnSe double-layer systems

We have investigated the magnetotransport properties of a series of magnetic semiconductor double layer structures consisting of 300 nm thick Ga1-xMnxAs and 150 nm thick Zn1-yMnySe layers. In this series, Mn concentration in the top Zn1-yMnySe varies from 28similar to42 %, while it is fixed at 5% in the Ga1-xMn,As. The transport measurement of the bottom Ga1-xMnxAs was carried out on the Hall bar prepared by using photolithography and selective etching processes. The temperature scan of resistivity data showed that the Curie temperature (T-C) of the Ga1-yMnxAs is increased in the form of double layers as compared to bare Ga1-xMnxAs. Furthermore, we have observed a systematic change of positive magnetoresistance (MR.) in the Ga1-xMnxAs, depending on the Mn concentration of the Znl_yMnySe overlayer. This observation clearly indicates that neighboring magnetic layers significantly influence the magnetotransport properties of the Ga1-xMnxAs.