If "any conventional photodiode" is a "classical" detector, then all photodiode detectors must also be quantum detectors, since they only work through quantum processes. My question remains unanswered: What is a non-quantum detector?
I should probably just read Gisin's experimental work directly, because it's not clear to me from your article exactly how the photon state (or even what state) is being determined.
Your explanation of a classical detector appears to imply the quantum-classical boundary, where quantum decoherence occurs. Perhaps you're describing macroscopic (multi-photon) detection vs. microscopic (single-photon) detection. Using a simple interferometer, for example, one can detect the average polarization state of mulitple photons by simply observing the fringes caused by constructive and destructive interference among the photons.
Nevertheless, any light detector--photodetectors, human eyes, or photographic film--is a quantum detector, by definition, because detection can only be accomplished through quantum absorption (or capture) at the atomic level. It doesn't matter whether it's a single photon or millions of them.
What caught my eyes is "up to 10 billion super cooled rare-earth ions".
Mining of rare-earth metals seems to be inevitable for the next generation technological advancement. As most people have heard, mining of rare-earth metals causes an exceptional pollution. Any short term solution to the issue? Where else can we dig out more rare-earth metal?
Yes, ID Quantique has customers, although not as many as they would like (the recession hit the financial community just as they were getting started which nixed their original business model, which was to get banks as customers for securing financial transactions). However, they still have more customers that the second successful quantum technology company, D-Wave (which only has Google, NASA and Lockheed).
Is this simply doping of a direct bandgap material (not so uncommon) or some fancy smancy new thing that will ultimately lead to teleportation, a la Star Trek! Seems like a bit more info would be helpful. Anyone got a link to point to a bit more detail?