Quantum leap towards computer of the future
By Rosanna Ryan
Updated 10 hours 50 minutes ago
Breakthrough: an artist's impression of a phosphorus atom (a red sphere surrounded by a blue electron cloud) coupled to a silicon single-electron transistor (College of Fine Arts, The University of New South Wales: William Algar-Chuklin)
An Australian-led team of scientists have taken a big step forward in the race to develop a quantum computer.
Quantum computing relies on harnessing the laws of quantum physics, which includes laws that apply to particles smaller than an atom, in order to get a computer to carry out many calculations at the same time.
Previous research has focused on using light, or materials other than silicon, in their work on quantum computers.
But the team, led by engineers from the University of New South Wales and the University of Melbourne, have been examining the properties of electrons embedded in silicon, which is cheaper, better-understood, and forms the basis of most electronics today.
To build a quantum computer, researchers need to be able to write information to an electron, by changing its "spin state", and to read information, by measuring its spin.
In an article published today in Nature, the researchers say they have cracked the second part of this puzzle, by creating a device that measures the spin state of a single electron in a single phosphorus atom inside a block of silicon.
"What we have demonstrated in this Nature paper is the ability to read out when the electron is in some random state," said co-author Andrea Morello.
"The next thing is to prepare it in exactly the state we want it."
Dr Morello's co-author, Professor Andrew Dzurak, says after a decade of work it is a special moment.
"Quantum computers won't speed up all day-to-day computing," he said.
"But there are three areas where we know it will be much faster: cracking most modern forms of encryption; searching databases; and modelling atomic systems such as biological molecules and drugs."
Professor Andrew White of the University of Queensland, who was not part of the research, says it is an "outstanding result".
"The whole world is exploring technologies to build quantum computers," he said.
"The team have made the key advance of showing they can read out information from these spins in a single fast measurement that faithfully transmits the information."
"This opens up the road for silicon quantum computing."
