Magnetic microscope image of three nanomagnetic computer bits. Each bit is a tiny bar magnet only 90 nm long. The microscope shows a bright spot at the “North” end and a dark spot at the “South” end of the magnet. The “H” arrow shows the direction of magnetic field applied to switch the direction of the magnets.

Credit: Jeongmin Hong, Jeffrey Bokor, EECS Department, UC Berkeley, from Hong, et al., Sci. Adv. 2016;2: e1501492, 11 March 2016. This work is licensed under Creative Commons.