Photons led astray
Life would sometimes be so much easier if we were quantum particles. For example, if we were trying to find our way out of a strange town allowing chance telling us which way to go at every intersection. As objects of classical physics, this would mean becoming more and more lost in the centre of the road network. If we were particles that obeyed the laws of quantum mechanics, we would sooner or later find our way to the edge of town on the randomly-chosen route. An international team headed by researchers at the Max Planck Institute for the Science of Light has now proven this experimentally. They have used polarised light - light waves which oscillate in a particular plane - to design a simple model for a quantum physical random walk. Their experiments could provide new insights into statistical processes such as photosynthesis, and help to accelerate search...