The light could be directed in numerous instructions, normally additionally again the identical approach. Physicists from the University of Bonn and the University of Cologne have, nevertheless, succeeded in creating a brand new one-way road for light. They cool photons right down to a Bose-Einstein condensate, which causes the sunshine to gather in optical “valleys” from which it may well now not return. The findings from the primary analysis may be of curiosity for the quantum communication of the long run. The outcomes are printed in Science.
A light beam is often divided by being directed onto a partially reflecting mirror: A part of the sunshine is then mirrored again to create the mirror picture. The remaining passes by way of the mirror. “Nevertheless, this course of will be rotated if the experimental set-up is reversed,” says Prof. Dr. Martin Weitz from the Institute of Utilized Physics on the University of Bonn. If the reflected light and the part of the sunshine passing via the mirror are despatched in the wrong way, the unique gentle beam may be reconstructed.
The physicist investigates unique optical quantum states of sunshine. Collectively along with his staff and Prof. Dr. Achim Rosch from the Institute for Theoretical Physics on the College of Cologne, Weitz was on the lookout for a brand new methodology to generate optical one-means streets by cooling the photons: On account of the smaller power of the photons, the sunshine ought to accumulate in valleys and thereby be irreversibly divided.
A beam of sunshine is thrown forwards and backward between two mirrors. Throughout this course, the photons collide with dye molecules situated between the reflecting surfaces. The dye molecules “swallow” the photons, after which spit them out once more. “The photons purchase the temperature of the dye resolution,” says Weitz. “In the middle of this, they cool right down to room temperature without getting misplaced.”
By irradiating the dye answer with a laser, the physicists improve the variety of photons between the mirrors. The robust focus of the sunshine particles mixed with simultaneous cooling causes the person photons to fuse to kind a “super-photon,” also referred to as Bose-Einstein condensate.