The new material has not yet been fabricated but has been christened “stanene”, a combination of the Latin word for tin (stannum) and the suffix found in the word graphene.
Stanene was discovered by researchers from the US Department of Energy’s (DOE) SLAC National Accelerator Laboratory and Stanford University and could revolutionize computing by replacing the copper
wires still used in modern computer chips.
Up until copper
has been relied upon to relay electricity in various forms - and for good reason. As well as being cheap and ductile, copper
is also very conductive. However, modern computer chips deploy the metal on a minute scale: in a modern chip the size of a thumbail, there can be up to 60 miles of copper
wiring, with some of the strands just atoms thick.
At this point scientists are pushing the limits of the material, channelling so much electricity through it that the material's electrical resistance causes the wires to heat, potentially setting it on fire. If stanene fulfils its promise, then chips could get smaller and faster without running this risk of overheating.
Stanene is a ‘topological insulator’, meaning its interior is an insulator but it conducts electrons along its surface. By making the material only a single atom thick, the stanene is essentially all surface, allowing it to conduct electricity with 100% efficiency.
By adding fluorine atoms to the mix, the scientist claim they can retain this level of efficiency at temperatures of up to 100C, allowing the material to be used in computers, where processors typically run at temperatures of between 40 and 90C.
However, there are many obstacles standing between stanene and mainstream use (not limited to the difficulties of manufacturing one-atom thick wires on an industrial scale) and without working samples of the material available it is perhaps a little early to get excited.
"Stanene could increase the speed and lower the power needs of future generations of computer chips, if our prediction is confirmed by experiments that are underway in several laboratories around the world," Shoucheng Zhang told Phys.org, a physics professor at Stanford and a team leader on the project. "The magic of topological insulators is that by their very nature, they force electrons to move in defined lanes without any speed limit. As long as they are on the edges or surfaces – the electrons will travel without resistance."
Experiments to confirm Zhang's group's simulations are currently underway in Germany and China, and if they succeed in fabricating stanene and confirm its properties, that could be good news for chip makers, since switching to thin ribbons of stanene for high-speed interconnects could cut chip power and reduce heat buildup.
Zhang has high hopes that their simulation results will be confirmed, since he and his colleagues already have a history of predicting the properties of topological insulators. Zhang's team already predicted that mercury telluride and several other compounds should be topological insulators that were subsequently confirmed experimentally. These compounds were predicted to conduct electricity with 100%v efficiency along their edges, when fabricated in monolayers, albeit only at low temperatures like a superconductor.
Zhang is also working on adding a gate to his stanene ribbons, in order to make three-terminal devices that replace the silicon in transistor channels with stanene. If successful, Zhang muses that someday the Silicon Valley may be renamed Tim Valley!