Feeds

Tiny transistor stays where it's put

Doing well with silicon and phosphorus – one atom at a time

Secure remote control for conventional and virtual desktops

The team that earlier this year characterized a four-atom wire that obeys Ohm’s Law has now demonstrated a repeatable single-atom transistor.

While single atoms have been observed acting like transistors in the past, the ‘device’ demonstrated by the UNSW, University of Melbourne and Purdue team is exceptional in that it has been engineered and can be built repeatably.

And with high precision: by creating a well-like structure to contain the atom, the researchers claim they’ve eliminated the 10nm positional uncertainties now observed in single-atom transistors.

As Dr Martin Fuechsle, lead author of the group’s paper (published in Nature Nanotechnology) explains, this accurate positioning is needed “if you want to use it as a qubit”. It was achieved by lifting one silicon atom out of a group of six using a scanning tunnelling electron microscope, and replacing it with the phosphorus atom.

The structure includes markers that allow researchers to attach contacts to it and apply a voltage.

Purdue's simulation of the single-atom transistor

The single phosphorus atom in its well in the centre

of a silicon crystal, shown in this Purdue simulation.

While the transistor exists as a single phosphorus atom, the entire structure is a little bigger: the atom has to be confined in a well or channel in a silicon crystal. It also needs to be kept at -196°C to operate, as Purdue’s Gerhard Klimeck explains.

“The atom sits in a well or channel, and for it to operate as a transistor, the electrons must stay in that channel.”

This explains the need for cold: “At higher temperatures, the electrons move more and go outside of the channel”.

"By achieving the placement of a single atom, we have, at the same time, developed a technique that will allow us to be able to place several of these single-atom devices towards the goal of a developing a scalable system,” says Michelle Simmons, director of UNSW’s ARC Centre for Quantum Computation and Communication.

Such techniques are also important, she says, because it allows an exotic device to be built using materials familiar to the computer industry.

A UNSW video discussing the technology is below. ®

Next gen security for virtualised datacentres

More from The Register

next story
Boffins attempt to prove the UNIVERSE IS JUST A HOLOGRAM
Is this the real life? Is this just fantasy?
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
NASA to reformat Opportunity rover's memory from 125 million miles away
Interplanetary admins will back up data and get to work
LOHAN tunes into ultra long range radio
And verily, Vultures shall speak status unto distant receivers
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
EOS, Lockheed to track space junk from Oz
WA facility gets laser-eyes out of the fog
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?