Jason Petta, Associate Professor of Physics, Princeton University
The coherent generation of light, from masers to lasers, relies upon the specific structure of the individual emitters that lead to gain. Devices operating as lasers in the few-emitter limit provide opportunities for understanding quantum coherent phenomena, from THz sources to quantum communication. I will describe a newly discovered maser, which is driven by single electron tunneling events. Semiconductor double quantum dots (DQDs) serve as a gain medium and are placed inside of a high quality factor microwave cavity. Maser action is verified by comparing the statistics of the emitted microwave field above and below the maser threshold.