Charge and spin transport in complex systems associated with spintronics

Scope and Method of Study: The purpose of this study was to explore charge and spin transport in several complex systems associated with spintronics. A distinct conductivity exponent observed at the percolation transition point in some colossal magnetoresistance (CMR) materials was studied by a real-space-renormalization method and numerical calculations. We also investigated the low temperature transport properties in a two dimensional electronic system coupled with phonons. After this, we studied spin entanglement effect between itinerant and localized electrons in a short one dimensional chain with low Fermi energy.