A European research team says it has demonstrated laser control of quantum states in an ordinary silicon wafer and has observed these states using conventional electrical measurement. The move is said by the team to be a crucial step towards future quantum technologies
In its experiments, the team – the University of Surrey, University College London, Heriot-Watt University, Radboud University in The Netherlands and ETH Zürich/EPF Lausanne/Paul Scherrer Institute in Switzerland –
demonstrated a quantum on/off switching time of about 1ps; said to be the fastest switching time yet achieved with silicon.
"Quantum computing exploits the fact that atoms can exist in two states at once, being both excited and unexcited at the same time," said Dr Ellis Bowyer, one of the Surrey researchers who made the laser measurements. "This is known as a superposition state and is most famously illustrated by Schrödinger's quantum cat, which is simultaneously dead and alive."
Dr Thornton Greenland from UCL added: "Quantum superpositions, and the resulting quantum technologies, are only just beginning to make an impact, but we believe that, with advances in silicon, it is only a matter of time before it becomes more part of the everyday. What is exciting is that we can see these exotic quantum phenomena in silicon using a measurement as simple as that of the electrical resistance."
The next phase of research could enable the creation of quantum silicon chips and devices such as super accurate clocks and ultra sensitive biomedical sensors.
