Scientists create world's thinnest material

Scientists create world's thinnest material

By Roger Highfield, Science Editor
Last Updated: 2:15AM GMT 02 Mar 2007

Do pencils point to the Holy Grail of physics?
Researchers have created the world’s thinnest sheet - a single atom thick - and used it to create the world’s smallest transistor, marking a breakthrough that could spark the development of super-fast computer chips.

This innovation will allow ultra small electronics to take over when the current silicon-based technology runs out of steam, according to Prof Andre Geim and Dr Kostya Novoselov from the University of Manchester.

They reveal details of transistors that are only one atom thick and fewer than 50 atoms wide in the journal, Nature Materials.

In recent decades, manufacturers have crammed more components on to microchips, with the number of transistors doubling every two years. But the ability to cram in more components is now decreasing.

Two years ago, Professor Geim and colleagues used graphite to find the real-world equivalent of a super-simple material that for the past half-century has been known only to theoreticians: a two-dimensional crystal - a single sheet of atoms. So called graphene is a gauze of carbon atoms resembling a chicken wire.

Graphene behaves as if the electrical current is not carried by normal electrons but by charged particles with no mass at all - when at rest akin to photons of light but which carry electric charge.

Graphene brings scientists close to ballistic transistors - ultimately faster than any current technology.

“A ballistic transistor is one in which electrons can shoot through without collisions, like a bullet,” he said.

The first graphene-based transistor was reported by the team at the same time but it was not practical.

Now the team has made the first graphene-based transistors suitable for use in future chips.

Prof Geim does not expect graphene-based circuits to come of age before 2025 but argues it will probably be the only viable way to shrink microelectronics after the silicon era comes to an end.

Working with the Dr Jannik Meyer of the Max-Planck Institute in Germany, Prof Geim also announces today in the journal Nature the first free hanging graphene sheet, a feat that had been thought to be impossible.

They report that free graphene is not perfectly flat but instead crumpled and this 'waviness’ may be responsible for the unexpected stability of these extremely thin carbon membranes.