Phys.org  May 10, 2022 An international team of researchers (France, Germany) built a on-chip circuit which is a simple battery-biased superconducting tunnel junction in series with a microwave resonator. At discrete values of the battery voltage, a dc current flows through the circuit, with the emission of several photons at the resonator frequency for each superconducting pair of electrons that tunnels across the junction. They measured the total microwave power emitted and characterized the granularity of the emission both of which were good agreement with a simple theoretical model. In particular, at a small transparency of the tunnel junction, they […]