The single-atom transistor

Shrinking transistors has been an obsession in the semiconductor world, but researchers Purdue University and the universities of New South Wales and Melbourne in Australia appear to have finally hit the limit of shrinkage. They’ve created a single-atom transistor that is just 0.1nm in width.

This comes on the heels of a development three months ago when the same research team developed a phosphorus and silicon wire that was one atom tall by four atoms wide, which they said behaves like copper wire.

The big challenge now is to control the electrons. At this size, quantum effects become the overriding issue. But the flip side is researchers are targeting this approach for quantum computing, where ones and zeroes are relative rather than fixed.

Custom Electrons

Designer molecules have revolutionized everything from medicine to modern warfare, but as atoms become observable they pass out of the realm of theoretical physics. That has led to the next step—designer electrons.
At the SLAC National Accelerator Laboratory, jointly run by Stanford University and the U.S. Department of Energy, scientists are now tuning electrons to behave in different ways. Working with graphene—sheets of carbon atoms—teams were able to change the symmetry of the electron flow, making them act as if they had been exposed to a magnetic field even though there was no magnetism involved.

What ultimately can be achieved with electrons is unknown. This is new research that most people never even considered five years ago. But the fact that it’s under way marks a significant shift in what ultimately could have a big impact on future semiconductors.
–Ed Sperling