Blog Post Image: Rice-sized laser, powered one electron at a time, bodes well for quantum computing

Princeton University researchers have built a rice grain-sized microwave laser, or “maser,” powered by single electrons that demonstrates the fundamental interactions between light and moving electrons, and is a major step toward building quantum-computing systems out of semiconductor materials. A battery forces electrons to tunnel one by one through two double quantum dots located at each end of a cavity (above), moving from a higher energy level to a lower energy level and in the process giving off microwaves that build into a coherent beam of light. (Photo courtesy of Jason Petta, Department of Physics)