Abstract

The age of electronically based semiconductor devices has been with us for six decades. With more and more electronic devices being packed into smaller and smaller spaces, the limit of physical space may prevent further expansion in the direction the microelectronics industry is currently going. However, a new breed of electronics, dubbed “spintronics” [1,2], ^* may alleviate the challenge. Instead of relying on the electron’s charge to manipulate electron motion or to store information, spin-tronics devices would further rely on the electron’s spin or its magnetic moment. In spintronics, electrons in a device can be easily manipulated by internal and external magnetic fields or spin-polarized electrical currents. The advantage of spin-based electronics or spintronics is that they are nonvolatile [1] compared to charge-based electronics, and quantum mechanical computing based on spintronics could achieve speeds unheard of with conventional computing. Spintronics will also lead to the emergence of ultrasensitive magnetic sensors, creating new and exciting applications.