The Tiniest Computer Unit On Earth: A Single Silicon Atom

An Australian team has created the world’s first working quantum bit based on a single atom in silicon, opening the way to ultra-powerful quantum computers of the future.

AsianScientist (Sep. 20, 2012) – Researchers in Australia have created the first working quantum bit based on a single atom in silicon, opening the way to ultra-powerful quantum computers of the future.

In a landmark paper published yesterday in the journal Nature, the team describes how it was able to both read and write information using the spin, or magnetic orientation, of an electron bound to a single phosphorus atom embedded in a silicon chip.

“For the first time, we have demonstrated the ability to represent and manipulate data on the spin to form a quantum bit, or ‘qubit’, the basic unit of data for a quantum computer,” said Scientia Professor Andrew Dzurak. “This really is the key advance towards realizing a silicon quantum computer based on single atoms.”

Dr. Andrea Morello and Professor Dzurak from the UNSW School of Electrical Engineering and Telecommunications led the team, which includes researchers from the University of Melbourne and University College, London.

Morello says that quantum computers promise to solve complex problems that are currently impossible on even the world’s largest supercomputers, including data-intensive problems, such as cracking modern encryption codes, searching databases, and modeling biological molecules and drugs.

The new finding follows a 2010 study also published in Nature, in which the same group demonstrated the ability to read the state of an electron’s spin. Discovering how to write the spin state now completes the two-stage process required to operate a quantum bit.

The new result was achieved by using a microwave field to gain unprecedented control over an electron bound to a single phosphorous atom, which was implanted next to a specially-designed silicon transistor. Professor David Jamieson, of the University of Melbourne’s School of Physics, led the team that precisely implanted the phosphorous atom into the silicon device.

“We have been able to isolate, measure, and control an electron belonging to a single atom, all using a device that was made in a very similar way to everyday silicon computer chips,” explained UNSW Ph.D. student Jarryd Pla, the lead author on the paper.

The team’s next goal is to combine pairs of quantum bits to create a two-qubit logic gate – the basic processing unit of a quantum computer.

The article can be found at: Pla JJ et al. (2012) A single-atom electron spin qubit in silicon.

——

Source: UNSW.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist