A Step Closer To Silicon-Based Quantum Computer

Australian researchers have taken a step closer to the construction of a large-scale silicon-based quantum computer.

AsianScientist (Jun. 27, 2013) – Australian researchers are a step closer to the construction of a large-scale quantum computer after they found a new way to distinguish between quantum bits that are placed only a few nanometres apart in a silicon chip.

Quantum bits, or qubits, are the basic building blocks of quantum computers – ultra-powerful devices that will offer enormous advantages for solving complex problems.

A qubit based on the spin of an individual electron bound to a phosphorus atom within a silicon chip is one of the most promising systems for building a practical quantum computer, due to silicon’s widespread use in the microelectronics industry.

“To be able to couple electron-spins on single atom qubits, the qubits need to be placed with atomic precision, within just a few tens of nanometres of each other,” said Professor Michelle Simmons, leader of the research team.

“This poses a technical problem in how to make them, and an operational problem in how to control them independently when they are so close together.”

In a quantum computer, information is stored in the spin, or magnetic orientation, of an electron. This spin can not only be in the two “classical” states – up and down – but also in a combination of both states at the same time, allowing exponentially larger amounts of information to be stored and processed in parallel.

In their study, published in Nature Communications, the researchers proposed a new method for distinguishing between neighboring qubits that are only a few nanometers apart and demonstrated the ability to read-out the spins of individual electrons on a cluster of phosphorus atoms that had been placed precisely in silicon.

The article can be found at: Buch et al. (2013) Spin Readout And Addressability Of Phosphorus-Donor Clusters In Silicon.

——

Source: UNSW; Photo: JamesIrwin/Flickr.
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