Brussels, 20 Jan 2006
Researchers from the University of Sussex in the UK have succeeded in manoeuvring a charged ion around a corner in a controlled environment. This breakthrough is a major step towards a quantum supercomputer, which would involve moving ions along atomic 'roads'.
While moving ions in a straight line has been possible for some time, this breakthrough has literally turned a corner by making the atoms take bends under the control of the researchers, showing that it is possible to fully control the ions.
The team, led by Dr Hensinger, lecturer in atomic molecular and optical physics at Sussex University, not only made the charged atom turn a corner, but also turn right around and go back the way it came. The quantum computer would require the mass control of atoms to function properly, and this is the first big step.
The ions are controlled by trapping them under electrical fields in a vacuum. The new technique involved shunting the ion along a track, laser-machined into a substance called alumina.
'This is big news because it is very difficult to trap atoms, let alone manipulate them in transit. This and other recent developments show that it should be possible to build a quantum computer with trapped ions. Now we can take two atoms and swap them around, which mathematically corresponds to a fundamental requirement for a quantum computer. This is the prerequisite to go from something academically interesting to something useful. This is a quantum leap in the development of the quantum computer,' said Dr Hensinger.
Recent developments by colleagues of Dr Hensinger have successfully used paired atoms to 'perform' tasks, in the same manner as would occur within a supercomputer. Grover's Quantum Search Algorithm can be used to perform super fast searches. Researchers used the atom pairs to look under four names in a directory to find the corresponding number. The correct answer was found 60 per cent of the time, better than the possible maximum of 50 per cent in a normal computer, a result of what Einstein called 'spooky action at a distance'.
Now both searching and movement can be controlled, the next quantum leap for quantum supercomputers will be just around the corner.
For further information, please contact:
University of Sussex Press office.
Remarks: For further detail, see T-junction multi-zone ion trap array for two-dimensional ion shuttling, storage and manipulation, W. K. Hensinger, S. Olmschenk, D. Stick, D. Hucul, M. Yeo, M. Acton, L. Deslauriers, J. Rabchuk and C. Monroe, Applied Physics Letters 88, 034101 (2006).