Light can be almost stopped at room temperature

15.04.16 - Alex Kruchkov, a PhD student at EPFL has found a way to slow down light at room temperature.

It is possible to force light to behave like a liquid, or more specifically a “quantum liquid” called a Bose-Einstein condensate. Controlling light like this could become the cornerstone of quantum computing, where information could be processed with security and speed far beyond our best computers today. But turning light – or any - particles into a sluggish liquid requires temperatures close to absolute zero. Another problem is that even if we confine light, in two dimensions, e.g. in a very narrow tube, light would still travel along the tube’s axis. But a PhD student at EPFL has now published a paper in Physical Review A showing that light can be slowed down into a condensate along the axis of a microtube, even at room temperatures.

First proposed in 1924 by Albert Einstein and Satyendra Nath Bose, the Bose-Einstein condensate represents a new state of matter where atoms form a kind of glob with exotic properties. This takes place very close to absolute zero (-273.15 oC), which is the temperature where all the classical motion of atoms ceases. This even applies to light particles, the photons: at extremely low temperatures, photons can coalesce to turn light into the condensate, but they vanish in cold.