Two-photon lasing by a superconducting qubit

Understand

We study the response of a magnetic-field-driven superconducting qubit strongly coupled to a superconducting coplanar waveguide resonator.

• We observed a strong amplification/damping of a probing signal at different resonance points corresponding to a one and two-photon emission/absorption.
• The sign of the detuning between the qubit frequency and the probe determines whether amplification or damping is observed.
• The larger blue detuned driving leads to two-photon lasing while the larger red detuning cools the resonator.