A QUANTUM MODEL FOR THE GIANT MAGNETORESISTANCE EFFECT

A quantum explanation based on the previous semi-classical theory has been presented for the giant magnetoresistance (GMR) effect in this le tter. A simple model Hamiltonian has been proposed for the conduction electrons in the magnetic layered structures in which the interaction of the conduction electrons with the local spins and the spin-dependen t scattering potential have been considered, then an analytical expres sion of the effective electric conductivity is derived after some simp lifying procedures. The main feature of the GMR effect may be explaine d by this simple model qualitatively.