Quantum teleportation coexisting with classical communications in optical fiber. Thomas et al 2024. https://opg.optica.org/optica/fulltext.cfm?uri=optica-11-12-1700&id=565936
Sounds to me like all they really have done in this paper is use the latest technology in fibre optics and recent observations of light scattering to send the imaginary quantum “entangled photons” down a very narrow bandwidth in a fibre optic cable. A bandwidth which is deemed to be less ‘busy’. And then pretend because that particular wavelength for the entangled signal was essentially cleared of all other offending data except the experimental signal it must be proof that somehow this implied two imaginary photons were “entangled” when surrounded by busy internet traffic in other wavelengths in the same fibre.
Two problems here. First is that these type of quantum entangled experiments always only compare signals AFTER they have been received at a detector. That’s called coincidence counting. Quantum theorists forget that the coincident counters in any entanglement experiment always collects and collates the data from different detectors arriving at different times down different length paths and then pretends that comparing the data later proves imaginary particles were somehow entangled. For more information on this misconception read Here .
And second, that by placing a horizontally polarised filter after a vertically polarised filter somehow this is proof that a magic quantum party trick was performed when no light comes through the two crossed filters.
There is no quantum magic in clearing out a particular range of wavelengths using filters etc. in the fibre and only sending and measuring data encoded within that narrow cleared bandwidth. That’s just an improvement in fibre optic manufacturing technology.
