Two{photon lasing by a superconducting qubit

Leibniz Institute of Photonic Technology, P.O. Box 100239, D-07702 Jena, Germany andNovosibirsk State Technical University, 20 K. Marx Ave., 630092 Novosibirsk, Russia(Dated: January 8, 2015)We study the response of a magnetic- eld-driven superconducting qubit strongly coupled toa superconducting coplanar waveguide resonator. We observed a strong ampli cation/dampingof a probing signal at di erent resonance points corresponding to a one and two-photon emis-sion/absorption. The sign of the detuning between the qubit frequency and the probe determineswhether ampli cation or damping is observed. The larger blue detuned driving leads to two-photonlasing while the larger red detuning cools the resonator. Our experimental results are in goodagreement with the theoretical model of qubit lasing and cooling at the Rabi frequency.