Diamond has a track record of extremes, including ultrahardness, higher thermal conductivity than any other solid material and transparency to ultraviolet light. In addition, diamond has recently become much more attractive for solid-state electronics, with the development of techniques to grow high-purity, single-crystal synthetic diamonds and insert suitable impurities into them (doping). Pure diamond is an electrical insulator, but doped, it can become a semiconductor with exceptional properties. It could be used for detecting ultraviolet light, ultraviolet light-emitting diodes and optics, and high-power microwave electronics. But the application that has many researchers excited is quantum spintronics, which could lead to a practical quantum computer—capable of feats believed impossible for regular computers—and ultrasecure communication.
Spintronics is an advanced form of electronics that harnesses not just the electrical charge of electrons (as in conventional electronics) but also a property called spin that makes electrons act like tiny bar magnets. Your computer probably already contains the first and most rudimentary commercial application of spintronics: since 1998 hard-drive read heads have used a spintronic effect called giant magnetoresistance to detect the microscopic magnetic domains on a disk that represent the 1s and 0s of the data it contains.
This article was originally published with the title "The Diamond Age Diamond Age of Spintronics" in Scientific American 297, 4, 84-91 (October 2007)
David D. Awschalom, Ryan Epstein and Ronald Hanson are associated with the Center for Spintronics and Quantum Computation at the University of California, Santa Barbara. Awschalom is director of the center and professor of physics and of electrical and computer engineering at Santa Barbara. His research group is primarily concerned with investigating electron-spin dynamics in a variety of semiconductor systems. Epstein obtained his Ph.D. in Awschalom¿s group, studying nitrogen-vacancy centers in diamond. He is now doing postdoctoral research on trapped ions at the National Institute of Standards and Technology in Boulder, Colo. Hanson was a postdoctoral researcher in the group and has just become assistant professor of physics at the Kavli Nanoscience Institute in Delft, the Netherlands. For his Ph.D., he studied single-electron spins in gallium arsenide quantum dots at the Delft University of Technology.