Spin-polarized transport and giant magnetoresistance——a basic physical feature of spintronics

An introduction to spin-polarized electron transport and giant magneto-resistance (MR), a basic physical feature of spintronics, in magnetic nanostructures and manganese oxides is given. Emphasis is placed on the giant MR in magnetic multilayers, tunneling MR in ferromagnetic tunnel junctions, and colossal MR in doped manganites.