Spin-orbit Interactions in High In-content InGaAs/InAlAs Inverted Heterojunctions for Rashba spintronics Devices

We studied novel InxGa1-xAs/InxAl1-xAs (x=0.5 and 0.75) inverted modulation-doped heterojunctions (HJs) as a candidate material for realistic Rashba spintronics devices. Large Spin-orbit coupling constants, > ~10X10-12 eVm, have been estimated in these HJs with both the In contents. Also the larger s were found in the HJs with thinner InGaAs channels due to the increase of the hetero-interface electric field. Moreover, higher In-content HJs seem to give larger s, since they have a narrower bandgap as well as a smaller electron effective mass.