Computing with a single electron

Australian engineers and physicists have developed a ‘single electron reader’, one of the key building blocks needed to make a quantum computer.

Computing with a single electron
Andrew Dzurak (left), Andrea Morello and their colleagues have read the spin of a single electron. Credit: UNSW
Quantum computers will use the spin, or magnetic orientation, of individual electrons for their calculations. And, because of the quantum nature of electrons, quantum computers could be exponentially faster at certain tasks than traditional computers.

In order to employ electron spin, a quantum computer needs both a way of changing the spin state (writing information) and of measuring that change (reading information). Together these two form a quantum bit or qubit – the equivalent of the bit in a conventional computer.

The Australian invention is a reader. The team is also working on a writer. Then they will combine pairs of these devices to create a 2-bit logic gate – the basic processing unit of a quantum computer.

The new device was made at UNSW with components from The University of Melbourne, and with assistance from researchers at Aalto University in Finland. By using silicon—the foundation material of conventional computers—rather than light or esoteric materials, the device opens the way to constructing a simpler quantum computer, scalable and amenable to mass-production.

“Quantum computers won’t speed up all day-to-day computing,” says project leader Andrew Dzurak from UNSW. “But there are three areas where we know they will be much faster: cracking most modern forms of encryption; searching databases; and modelling atomic systems such as biological molecules and drugs.”

Photo: Andrew Dzurak (left), Andrea Morello and their colleagues have read the spin of a single electron.
Credit: UNSW

UNSW/Australian Research Council (ARC) Centre of Excellence for Quantum Computer Technology

Andrew Dzurak, +61 2 9385-6311, A.Dzurak@unsw.edu.au, http://cqc2t.org/