8. Magnetic Nanowires for Domain Wall Logic and Ultrahigh Density Data Storage

Spintronics describes the concept of attempting to use both the charge and the spin on the electron in microelectronic devices [1, 2]. One of the most highly sought after functionalities in microelectronics is non-volatility, i.e. the ability to retain memory even when power is removed. This is particularly true as the popularity of mobile electronic communication and computing devices grows. In principle, ferromagnetic materials could provide this functionality, due to the hysteresis, and hence memory, that accompanies most ferromagnets. Unfortunately, no suitable room temperature ferromagnetic semiconductor material has yet been identified [3]; the most common ferromagnetic materials are metals. The aim of this research has been to see how far we can push the properties of basic ferromagnetic metallic alloys, which are usually considered to have relatively simple magnetic and electrical properties, towards highly functional devices which mimic and complement the digital logic functions and non-volatile data storage functions of semiconductor microelectronics. Using the concept of the domain wall conduit, we show how information can be represented, moved, processed and stored in networks of ferromagnetic nanowires.