Experiment

  • In https://pmc.ncbi.nlm.nih.gov/articles/PMC12315985/ (Wang et al., Science Advances, 2025), it is claimed that a Bell inequality is violated in a four-photon interference setup, even though the photons involved are not described as entangled within the system. The report names quantum indistinguishability via path identity as the mechanism and uses postselection on four-fold coincidences; the Bell parameter…

  • In the microscopic theory of superconductivity by Bardeen, Cooper & Schrieffer (1957), an energy gap leads to strongly suppressed dissipative quasiparticle contributions at low temperatures, enabling a very low-loss reference mode of operation. Josephson (1962) predicts, for tunnel junctions, a lossless DC supercurrent up to a critical limit as well as a dissipative voltage state…