Scientists have created what they claim is the world’s smallest transistor, using a single phosphorus atom. An international team at the University of New South Wales, Purdue University and the University of Melbourne, has described the smallest transistor ever built in the Nature Nanotechnology journal.
Michelle Simmons, who led the team, says the development is less about improving current technology than building future technology. “This is a beautiful demonstration of controlling matter at the atomic scale to make a real device. Fifty years ago when the first transistor was developed, no one could have predicted the role computers would play in our society today.
“As we transition to atomic-scale devices, we are now entering a new paradigm where quantum mechanics promises a similar technological disruption. It is the promise of this future technology that makes this present development so exciting,” Simmons said.
A single phosphorus atom is just 0.1 nano meters across, which would significantly reduce the size of processors made using this technique, although it may be many years before single-atom processors actually are manufactured.
However, the single-atom transistor does have one serious limitation — it must be kept very cold, at least as cold as liquid nitrogen, or minus 196 Celsius.
“The atom sits in a well or channel and for it to operate as a transistor the electrons must stay in that channel. At higher temperatures, the electrons move more and go outside of the channel. For this atom to act like a metal you have to contain the electrons to the channel.
“If someone develops a technique to contain the electrons, this technique could be used to build a computer that would work at room temperature. But this is a fundamental question for this technology,” Gerhard Klimeck, a team member, said in a release by Purdue University.