A substantial development has been made in spintronics research since the last decade. Spintronics deals mainly with the science and technology of using the spin degree of freedom of a charge carrier for various applications such as storing, encoding, accessing, processing and to transmit information in some manner. Interest in spintronics is encouraged by replacing the charge of the electron with the spin of the electron. This book includes various aspects associated with the physics and technology of spintronics.