Property of Topological Insulators Induced in GrapheneCategory: Science & Technology
Posted: December 24, 2013 08:02AM
Presently silicon and other semiconductors are dominant in computers, but in the future graphene and topological insulators may replace them. This is because both materials have special properties that could be exploited for some interesting applications. Now researchers at MIT have discovered a way to bring a property of topological insulators to graphene, and this has never been observed before.
Graphene is an atom-thick sheet of carbon with unique characteristics resulting partially because of its two-dimensional structure. What makes topological insulators special is that their interiors are electrical insulators while their surfaces are highly conductive. This leads to some very interesting quantum mechanical effects, such as electron spin determining what way a current flows around the topological insulators. What the researchers have discovered is that this exact phenomenon can be duplicated with graphene by chilling it to just about absolute zero and applying two magnetic fields to it. Normally graphene will conduct currents along it entire area, but when a magnetic field is applied perpendicular to the plane, the current only moves around the edges. The researchers applied the second field parallel to the plane, and this caused the spin segregation.
This spin selectivity could one day be used to create advanced quantum computers, especially as it is possible to control within the graphene, possibly to the point of making circuits and transistors. The researchers are now working to make it easier to stimulate this phenomenon, as 0.3 K is not a very easy temperature to work in.