The Oldenburg physicists Dr Christoph Weiß and Niklas Teichmann (Condensed Matter Theory Group) have discovered an interesting connection between "classical chaos" and quantum correlations. They report on this in the renowned journal "Physical Review Letters". Perhaps the best-known example of how small changes in chaotic systems can cause large effects is the so-called butterfly effect: the flap of a butterfly's wings can trigger a storm at a great distance. This by no means refers to the phenomenon that a snowball can trigger an avalanche, but rather the extreme sensitivity of a chaotic system with regard to changes in the initial conditions. The authors show that for a system of ultracold atoms in two potential wells that wobble periodically, a quantum mechanical investigation can be carried out in addition to a classical analysis of the system. Surprisingly, many-particle quantum correlations occur in computer simulations when the classical system behaves chaotically. Such quantum correlations play a key role in the realisation of quantum computers, for example, and are a focus of current research. The two scientists hope that their findings will stimulate experimental investigations in this "highly exciting field of physics", according to Weiß.
Parts of the work were carried out in Paris with financial support from the European Union. Weiß conducted research there at the prestigious Laboratoire Kastler Brossel, and Teichmann took part in a three-month workshop at the Institute Henri Poincaré.