Field-Coupled Magnets Could Replace Transistors In Some Computer Chips

Electrical engineers at the Technische Universitit Mi1/4nchen (TUM) have demonstrated a new kind of building block for digital integrated circuits. Their experiments show that future computer chips could be based on three-dimensional arrangements of nanometer-scale magnets instead of transistors. As the main enabling technology of the semiconductor industry - CMOS fabrication of silicon chips - approaches fundamental limits, the TUM researchers and collaborators at the University of Notre Dame are exploring "magnetic computing" as an alternative.

Think of the way ordinary bar magnets behave when you bring them near each other, with opposite poles attracting and like poles repelling each other. Now imagine bringing several bar magnets together and holding all but one in a fixed position. Their magnetic fields can be thought of as being coupled into one, and the "north-south" polarity of the magnet that is free to flip will be determined by the orientation of the majority of fixed magnets. Gates made from field-coupled nanomagnets work in an analogous way, with the reversal of polarity representing a switch between Boolean logic states, the binary digits 1 and 0.