A new state of light

05.05.2014 - A theoretical physicist has been able to explain how to capture particles of light at room temperature.

In doing so, Alex Kruchkov has confirmed the existence of a ‘new state of light’ which could pave the way for advanced computer chip, laser and solar panel technology

Previously, getting hold of these particles - called photons - was only thought to be possible under extremely cold temperatures. Light is made up of tiny quantum particles called photons. Physicists know that when quantum particles condense, they lose their individual identity. Their different energy levels collapse into a single macroscopic quantum state, causing them to behave like clones and form a ‘super particle’ or wave known as a Bose-Einstein condensate (BEC). This usually happens at extremely low temperatures of less than a micro-kelvin, or a millionth of a degree above absolute zero, according to a report by Katia Moskvitch on Live Science. Chilling rubidium atoms down to a low enough temperature in a compact space, for instance, causes them to quickly become indistinguishable, behaving like a single particle. A long-standing question in physics has been whether or not photons can be condensed like other quantum particles such as rubidium atoms. In theory it should work, but the main obstacle to proving the effect has always been that photons have no mass, which is a key requirement for a Bose-Einstein condensate. But in 2010, physicists from Bonn University in Germany were able to successfully condense photons in something known as a micro-cavity – a device made of two mirrored surfaces.The surfaces trapped a photon, which then behaved as if it had a mass.