Magnetic Logic and Magnetic Computing Spin-Based Devices

The field of spintronics emerged from discoveries in the 1980s concerning spin-dependent electron transport phenomena in solid-state devices [1]. One of the key discoveries that led to the development of spintronics was the observation of spin-polarized electron injection from a ferromagnetic metal to a normal metal by Johnson and Silsbee in 1985 [2]. This effect, known as spin injection, involves the transfer of electrons from a ferromagnetic material to a nonmagnetic material while preserving their spin polarization [3]. This discovery was followed by other important developments in the field of spintronics, including the observation of giant magnetoresistance (GMR) by Albert Fert and Peter Grünberg in 1988 [4]. GMR is a phenomenon where the resistance of a material changes in the presence of an external magnetic field, and it is the basis for magnetic read heads used in hard disk drives. Since then, the field of spintronics has expanded rapidly, and it has led to the development of a wide range of spin-based devices, including spin valves [5], magnetic tunnel junctions [6], and spin transistors [7].