Computing with magnetism: spintronic logic from a circuit and system point of view
Christoph Adelmann, Fanfan Meng, Anais Guerenneur, Daniele Narducci, Frederic Vanderveken, and Florin Ciubotaru. imec, 3001 Leuven, Belgium
Based on the success of magnetic memories (MRAM), researcher have been interested for many years in extending the work to magnetic logic also. Recently, this has been received increasing attention because of the prospects of achieving high-density ultra-low power circuits. However, many challenges remain that need to be solved before spintronic logic can be integrated in real world applications. Embedding spintronic circuits requires transducers between electric and magnetic signals at between spintronic logic and conventional CMOS-based periphery. We show that current MRAM-derived transducers have much too low energy efficiency to enable spintronic logic applications. By contrast, magnetoelectric transducers promise much higher energy efficiency and may thus be considered as key devices in spintronic logic systems. We review the state of the art of magnetoelectric transducers and indicate targets and future directions of research. Besides transducers, the implementation of logic operations by magnetic systems will also have a major effect of energy efficiency and computing throughput. We compare approaches based on nanomagnets, domain walls, and spin waves and demonstrate how requirements of circuit design will affect the different spintronic logic gate concepts.