Quantum computers promise ultra-powerful, high speed number crunching. They’ll help us to search vast databases and model biological molecules at an atomic level. They will crack the encryptions we rely on for banking and online security but also help us make new, unbreakable codes.
How close are we to building a quantum computer? Australian scientists are working on it.
Also at the national physics congress today: meet the man in charge of planning and designing the NBN; designing a cheaper high-precision clock for GPS, astronomy and space tracking; and fighting greenhouse gases and arc-welding fumes with super-heated thermal plasma.
These stories are from the national physics conference, AIP/ACOFT 2012, at UNSW in Sydney this week.
The man leading the design of Australia’s information superhighway
Meet the man whose job it is to figure out how to build the NBN.
Prof Peter Ferris, NBN Co. Executive General Manager of Planning and Design, is speaking about the NBN’s structure, what it was designed to do, the clever software behind determining access to it and where it will run, and the general schedule of its deployment.
A new, cheaper way to deliver accurate time across Australia
The GPS system, space tracking, geological mapping, and the SKA all depend on incredibly accurate measurement of time—knowing exactly when events occur and coincide across the entire continent.
Instead of using individual hydrogen maser clocks costing hundreds of thousands of dollars, researchers reckon we could bounce signals through the national’s optical fibre network.
Physicists from a consortium including five Australian universities, AARNet, the CSIRO, the National Measurement Institute (NMI) and the Paris Observatory are involved in the National Time and Frequency Network project which aims to set up a more accurate service at a fraction of the cost using optical fibre links.
The strategy is to send a precise burst of light through the optical fibre network from the NMI in Sydney to a receiver in another part of the country which will return the signal. Disruptions due to environmental effects, such as heat or seismic disturbance, are measured continuously with very high precision and can thus be compensated.
The magic of thermal plasmas – from safer arc welding to saving the ozone layer
Australia’s guru of thermal plasmas will be recognised tonight with the Harrie Massey Medal.
Thermal plasmas are ionised gases raised to very high temperatures (to almost 30,000 degrees Celsius). Tony Murphy’s lifetime of research on thermal plasmas has contributed to destroying greenhouse gases and ozone-depleting substances, and reduced the health risks from arc welding – arising from fume particles caused by metal vapour during arc welding.
Quantum computing – how close are we?
Quantum science is a major theme in physics research. Australian scientists are working to make this powerful, high-speed computing a reality.
- UNSW’s Andrew Dzurak talks about progress in quantum computing and his team’s creation in September of a quantum bit – writing and reading the quantum state of a single electron in a silicon system – like in conventional computers
- Two ANU research teams report on how to make quantum devices more stable; and switching eight beams of entangled light in a laser – for high speed networks.
- A Macquarie team reports on a new room temperature source of single photons.
- And Ben Eggleton from Sydney reveals progress towards a light powered computer chip.
Fighting fire with fire
Until now quantum computing systems have been very fragile and easily disrupted. Dr Andre Carvalho from ANU and Mr Martin Ringbauer from the University of Vienna will talk about ways in which researchers are fighting back and stabilising quantum systems.
One source of fragility is in the fact that quantum devices can spontaneously emit energy, destroying their useful characteristics. The solution to this, says Andre Carvalho and his colleagues, seems counterintuitive. They have shown that adding more energy to the system using laser light actually allows it to maintain its integrity, provided the system is measured in the right way.
Another source of fragility is that up till now typical quantum computing systems have been based on elements linked by what is called entanglement—whatever happens to one element of an entangled pair automatically and instantaneously happens to the other.
But entanglement is easily disrupted. Mr Ringbauer and his colleagues suggest entanglement may be unnecessary, even counterproductive. If the level of discord of the system can be assessed, interpreted and taken into account, he says, then efficient information processing can still take place.
Mr Seiji Armstrong and his colleagues at ANU were profiled on ABC-TV’s New Inventors when they showed they could squeeze multiple entangled beams of light or modes into one laser, allowing for faster and more efficient transfer of information.
They can now use one detector in real time to switch between up to eight of these modes in a single laser beam. It’s all part of developing the next-generation super-fast networks needed to drive the quantum computing of the future.
Materialising quantum sensors
Silicon carbide (SiC) looks like becoming a material of choice for quantum sensors, says Dr Stefania Castelletto of Macquarie University. Her research group has been the first to use the material as a stable, room temperature source of single photons. The work paves the way to merge together several areas of quantum research and should allow the engineering of fully integrated quantum devices, she says.
A new chip, which uses light instead of electronic signals to process information, could lead to high security, energy-efficient internet links more than 1,000 times faster than today’s networks.
This “photonic chip” uses special glass, photonic crystals, to bend light and slow it down. The slower the light travels, the more efficiently the chip can operate—and the smaller and more energy efficient the resulting devices can be.
Developed by Prof Ben Eggleton and his team at the Australian Research Council Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS) at the University of Sydney, the same technology could be used to build quantum computers and secure communications networks.
Key contact details for AIP/ACOFT 2012
The media website is at http://www.scienceinpublic.com.au/category/physicscongress
The conference website is at http://www.aip2012.org.au
Niall Byrne, +61 (417) 131-977, email@example.com
AJ Epstein, + 61 (433) 339 141, firstname.lastname@example.org
Margie Beilharz, +61 (415) 448 065, email@example.com