Casey Kristin Frye
Feb 27, 2012

Berkeley Lab researchers resolve controversy over gallium manganese arsenide that could boost spintronic performance

A long-standing controversy regarding the semiconductor gallium manganese arsenide, one of the most promising materials for spintronic technology, looks to have been resolved. Devices equipped with spintronic technology utilize electron spin rather than charge to read and write data, resulting in smaller, faster and much cheaper data storage and processing. Researchers with the US Department of Energy’s Lawrence Berkeley National Laboratory in collaboration with scientists from University of Notre Dame have determined the origin of the charge-carriers responsible for the ferromagnetic properties that make gallium manganese arsenide such a hot commodity for spintronic devices. Scientists showed that the holes (positively-charged energy spaces) in gallium manganese arsenide that control the Curie temperature, the temperature at which magnetism is lost, are located in an impurity energy band rather than a valence energy band, as many scientists have argued. This finding opens the possibility of fabricating gallium manganese arsenide so as to expand the width and occupation of the impurity band and thereby boost the Curie temperature to improve spintronic potential.