Quantum computers get closer

RESEARCHERS CLAIM that they are closer to creating quantum computer chips using ordinary technology.

Manufacturing techniques required to make quantum devices so far have been a bit too exotic for your average PC.

However now boffins at Ohio State University have discovered a way to make quantum devices using technology common to the chipmaking industry today.

They say that one day it will enable faster, low-power computer chips.

Top boffin Paul Berger fabricated a device called a tunnelling diode using chemical vapour deposition, the most common chip wafer manufacturing method.

He said he had developed a technique that manufacturers could potentially use to fabricate quantum devices directly on a silicon chip, side-by-side with their regular circuits and switches.

The bit he has made is a resonant interband tunnelling diode (RITD). This enables large amounts of current to be regulated through a circuit, but at very low voltages.

So far RITDs have been difficult to manufacture because they contain chemical elements such as antimony or phosphorus that can't be stuck on a silicon crystal.

Researchers tried adding the dopants while growing the silicon wafer one crystal layer at a time. But they found this is slow and expensive, can't be used in manufacturing and creates too many defects within the silicon.

However Berger discovered that RITD chemicals could be added during chemical vapor deposition, in which a gas carries the chemical elements to the surface of a wafer many layers at a time.

Tunnelling diodes exploit a quantum mechanical effect that lets electrons pass through thin barriers unhindered.

Berger thinks that his RITDs can be used for ultra-low-power computer chips operating with small voltages and producing less wasted heat.

Of course that assumes that the cat is really alive but does not put its paws on something important in the computer's workings. We guess it means that you will have to always observe your chips so that they don't become something else, like a badger. µ