Quantum devices will revolutionise computing, enabling huge calculations to be completed that classical computers simply cannot do.

We're now one step closer to quantum computing becoming a reality thanks to research led by a team of University of Sydney physicists, who have found a new way to detect changes in charges smaller than one electron.

The research is published in this week's edition of Physical Review Letters.

"Our new method for detecting charge in quantum systems is exciting and has implications for a range of nanotechnologies," said Associate Professor David Reilly, from the ARC Centre for Engineered Quantum Systems in the School of Physics at the University of Sydney.

"We've been successful in finding a new, more convenient way to detect changes in charge of a single electron on quantum dots. Quantum dots are nanoscale systems that can confine or trap single electrons," explained Associate Professor Reilly.

"Electrons confined to quantum dots are very nice systems for storing and manipulating quantum information, where data is encoded in the quantum mechanical aspects of the electron. Our goal is to scale-up a large number of quantum dots to ultimately create a machine to process quantum information—a quantum computer."

Ever since Nobel Prize winner Richard Feynman highlighted the potential of quantum computing in the 1980s, scientists have been attempting to build quantum computers capable of solving some of the largest and most complex problems, with much greater efficiency than conventional computers.

"We've focused on quantum dots as their properties can be tuned in the laboratory—we can control their energy spectrum by turning a knob in the lab."

"Being able to detect single electron charges on the quantum dots is absolutely essential, as it's the way information is retrieved from such quantum mechanical systems. We call it 'read-out' and it's analogous to reading information from the memory or a hard drive in a regular classical computer," said Associate Professor Reilly.