Unusual magnetic properties of MnAs thin films: A new approach to magnetologic computing

Taking advantage of the spin information in nowadays computing is expected to yield an enormous increase in efficiency. A promising ferromagnetic material compatible with semiconductors for room temperature applications is MnAs. We discovered that α-MnAs films on GaAs(0 0 1) exhibit an additional small volume fraction with an out-of-plane magnetization component. Sensitive cantilever beam magnetometry reveals that it is magnetically coupled with the predominant in-plane magnetization, thus enabling magnetization reversal by both an in-plane and an out-of-plane magnetic field. We show that by regarding the two magnetic fields as independent inputs, the α-MnAs layer can be utilized as logic gate with AND or OR functionality. On basis of the experimental results, a general hardware-concept for a reprogrammable logic is presented. We show that a single magnetoresistive element, which combines the inherent advantage of a non-volatile output with flexible functionality, can be programmed at run-time to be AND, OR, NAND or NOR.