Two-photon emission from a superlattice-based superconducting light-emitting structureOACSTPCD

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and robustness.One example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper pairs.However,the two-photon nature of the emission has not been shown experimentally before.We demonstrate two-photon emission in a GaAs/AlGaAs SLED.Measured electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(Tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,T))demonstrate temperature-dependent time coincidences below Tc between photons emitted from the SLED.Our results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.