Nanomagnets to replace silicon transistors?

The TUM researchers and collaborators at the University of Notre Dame are exploring 'magnetic computing'. Using a 3D stack of nanomagnets, the researchers have implemented a majority logic gate, which could serve as a programmable switch in a digital circuit. The underlying principle can be explained using bar magnets as an example. If several bar magnets are brought together and all but one held in a fixed position, their magnetic fields can be thought of as being coupled, with the polarity of the free magnet determined by the orientation of the majority of fixed magnets. Gates made from field coupled nanomagnets are said to work in a similar way, with the reversal of polarity representing a switch between logic 1 and logic 0. In the 3D majority gate developed by the researchers, the state is determined by three input magnets, one of which sits 60nm beneath the other two and is read out by a single output magnet. Dr Markus Becherer, leader of the research group, noted: "It is a big challenge to compete with silicon CMOS circuits. However, there might be applications where the non-volatile, ultra low power operation and high integration density offered by 3D nanomagnetic circuits give them an edge." Nanomagnetic circuits are said to have extremely low power consumption, to operate at room temperature, resist radiation and be packed densely. The team also suggests that it can require fewer magnets than transistors to create a particular function.