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 found a granularity equal to the size of the photon bunches. The researchers did not test the photons to determine if they were entangled, but believe they were entangled based on prior experiments they had conducted. They also did not attempt to modify the device to determine if more than six photons could be produced. More testing is required, but if the device works as hoped, it could signal the start of a new wave of research based on groups of entangled particles. The work provides a particularly pure, controllable, and well-understood test bench for quantum physics…read more. Open Access TECHNICAL ARTICLEÂ
A device for producing up to six photons in a single event could open new doors to quantum technologies. Credit: Phys. Rev. X 12, 021006, 8 April 2022Â