Researchers clear final quantum hurdle

05.10.2015
Researchers at the University of New South Wales say they have cleared the final hurdle to making silicon quantum computers a reality.

Engineers have built a quantum logic gate in silicon for the first time, making calculations between two qubits of information possible.

Andrew Dzurak, Scientia professor and director of the Australian National Fabrication Facility at UNSW, said on Tuesday that the discover was a game changer.

"We've demonstrated a two-qubit logic gate - the central building block of a quantum computer - and significantly, done it in silicon. Because we use essentially the same device technology as existing computer chips, we believe it will be much easier to manufacture a full-scale processor chip than for any of the leading designs, which rely on more exotic technologies.

"This makes the building of a quantum computer much more feasible, since it is based on the same manufacturing technology as today's computer industry," said Dzurak.

Until now, it has not been possible to make two quantum 'bits' talk to each other, and create a logic gate using silicon. The UNSW team - working with Professor Kohei M. Itoh of Japan's Keio University - have done that for the first time.

This means that all of the physical building blocks for a silicon-based quantum computer have now been successfully constructed, allowing engineers to finally begin the task of designing and building a functional quantum computer.

The UNSW team reconfigured the transistors that are used to define the bits in existing silicon chips and turned them into qubits.

"The silicon chip in your smartphone or tablet already has around one billion transistors in it, with each transistor less than 100 billionths of a metre in size," said Dr Menno Veldhorst, a UNSW research fellow and lead author of an article published about the discovery in Nature.

"We've morphed those silicon transistors into quantum bits by ensuring that each has only one electron associated with it. We then store the binary code of 0 or 1 on the spin of the electron, which is associated with the electron's tiny magnetic field," he said.

The UNSW team had recently patented a design for a full scale quantum computer chip that would allow for millions of qubits, all doing the types of calculations that have just been demonstrated.

UNSW's Dzurak said the team now needed to identify the right industry partners to work with to manufacture the full-scale quantum processor chip.

The university believes a full-scale quantum processor would have major applications in the finance, security and healthcare sectors. The will allow the identification and development of new medicines by accelerating the computer-aided of pharmaceutical compounds, and aid in the creation of lighter and stronger materials from consumer electronics to aircraft.

UNSW has been at the forefront of quantum discoveries. In April, researchers said they had encoded quantum information in silicon using simple electrical impulses, which is one of several advances the team has been working on in recent years.

In late 2012, Dzurak told CIO that is would be 20 years before quantum computers capable of modelling and simulating complex biological and chemical systems to create new materials will become commercially available.

Read more:Researchers find ancient volcanoes off Sydney coast

Follow CIO Australia on Twitter and Like us on Facebook… Twitter: @CIO_Australia, Facebook: CIO Australia, or take part in the CIO conversation on LinkedIn: CIO Australia

Follow Byron Connolly on Twitter:@ByronConnolly

Read more:Former Intersect boss joins UNSW

Read more:Australia an innovation laggard: Where we went wrong

(www.cio.com.au)

By Byron Connolly