Title: Frequency tunable single photon emitter using double transmon coupler architecture

Single photon emitters and detectors enable entanglement distribution on quantum networks. Here we present a compact and straightforward single photon emitter at microwave frequencies based on the recently developed double transmon coupler (DTC) superconducting circuit architecture. One DTC transmon stores a photon while the other transmon releases the photon into the waveguide radiation field. The two transmons do not have the same frequency, which makes state preparation bleedthrough into the radiation field ignorable or filterable. We use parametric modulation of the DTC flux to shape the outgoing waveform of the emitted photon while the steady state flux bias sets the frequency of the outgoing photon.