Remember playing with the bulky transistors that came with your first electronics kit? The most important part of modern electronics, the transistor has been shrinking since its discovery in the 1920's. Smaller transistors mean smaller and faster chips, and now scientists have found the smallest transistor to date.
A functional transistor recently discovered by researchers from Finland and Australia has an active region composed of a single atom. Although this transistor would be difficult to incorporate into your DIY project, its discovery means that a new generation of atom-scale processors could be close at hand, leading eventually to nano-scale computers and devices.
This tiny device uses the strange effects of quantum mechanics to its advantage. When conditions are right, electrons can tunnel through a physical barrier. The single atom transistor uses quantum tunneling, controlled by changes in voltage on an electrode, which allows electrons to move between the single phosphorus atom and the leads of the transistor. The article announcing this device, published in Nano Letters, says that the transistor can be controlled precisely enough for it to be useful for future nanoelectronics.
Dr. Mikko Möttönen, one of the scientists working on this project, said that the team's intention wasn't "to build the tiniest transistor for a classical computer, but a quantum bit which would be the heart of a quantum computer that is being developed worldwide". With applications for both classical and quantum computing, this tiny device has a big future.