Quantum reflection shields ultracold atoms

A team of researchers from the Massachusetts Institute of Technology (MIT) experimentally demonstrated quantum reflection. In their experiment, sodium atoms were cooled below 10nK. A novel feature of the experiment was that instead of forcing individual atoms to collide with a material surface, the entire Bose-Einstein condensate was collided with a silicon surface located in the middle of the confining trap. The group derived quantum-reflection probabilities of up to 70% by counting the member of atoms surviving in a trap in the presence of the silicon surface.