Researchers suggest novel way to generate a light source made from entangled photons

Phys.org  September 9, 2022 Researchers at Purdue University have proposed the generation of attosecond entangled biphotons in the extreme-ultraviolet regime by two-photon decay of a metastable atomic state as a source like spontaneous parametric down-conversion photons. The 1s2s1S0 metastable state in helium decays to the ground state by the emission of two energy-time entangled photons with a photon bandwidth equal to the total energy spacing of 20.62 eV. This results in a pair correlation time in the attosecond regime making these entangled photons a highly suitable source for attosecond pump-probe experiments. They calculated and used the biphoton generation rate from […]

On-chip circuit produces up to six microwave photons at the same time

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 […]

Researchers generate tunable twin particles of light

Phys.org  May 11, 2021 A team of researchers in the US (University of Maryland, University of Illinois) demonstrated a tunable source of indistinguishable photon pairs using dual-pump spontaneous four-wave mixing in a topological system comprising a two-dimensional array of resonators. They exploited the linear dispersion of the topological edge states to tune the spectral bandwidth (by about 3.5×), and thereby, tuned quantum interference between generated photons by tuning the two pump frequencies. They demonstrated energy−time entanglement and, using numerical simulations, confirmed the topological robustness of the source. Their results could lead to tunable, frequency-multiplexed quantum light sources for photonic quantum […]