A Josephson Maser Via Three-Wave Coupling

In superconducting quantum information systems, we require coherent light to drive quantum elements such as qubits and quantum amplifiers. This is traditionally achieved by filtering hot, room temperature light sources through 60-80dB of increasingly cold attenuators. A cryogenic maser operated in the 5-10GHz range, if it could be controlled without an external microwave drive, would be ideal for such coherent drives. Instead of a three-level atom, we present a joint system of a single qubit and a three-wave mixing resonator, realized in a transmon and SNAIL (Superconducting Nonlinear Asymmetric Inductive eLement), respectively. We take advantage of the SNAIL’s parametric gain process and large engineered loss to rapidly invert the transmon’s population and drive masing in a superconducting cavity. We will present the project’s preliminary experimental results, as well as plans to implement the parametric drive via a dc-biased junction for an all-dc controlled, cryogenic quantum light source.