'Atomtronics' May Be The New 'electronics' - Science News: A second pair of lasers transferred energy to the doughnut to start it rotating. Because atoms in the condensate behave as a single, coherent quantum particle, such a ring of the substance doesn’t speed up or slow down gradually — it jumps between different speeds, much like a blender would if it could change settings instantaneously. The scientists chose the lowest setting for their ring, about one revolution every second.
Because the condensate also happens to be frictionless, this ring should, in theory, rotate forever. Limited by technical difficulties, the research team kept it going for about 40 seconds, the lifetime of their condensate.