3 ms·
Wow, that seems really interesting that you might not need a very expensive setup to demonstrate entanglement then. I'm just reading more about the bell test.
by anfractuosity 7y ago
Wow, that seems really interesting that you might not need a very expensive setup to demonstrate entanglement then. I'm just reading more about the bell test.
Edit: I just found this talk https://www.youtube.com/watch?v=tn1sEaw1K2k https://www.youtube.com/watch?v=tn1sEaw1K2k which looks really interesting 'Shanni Prutchi Construction of an Entangled Photon Source'. It looks like she's using SPADs for detection of the photons.
- ahelwer 7y agoYeah, the expensive/hard part is generating & measuring only a single photon at a time. Of course if you fire a laser through an SPDC crystal a bunch of photon pairs will come out entangled, but that isn't terribly useful for most entanglement experiments.
- anfractuosity 7y agoAh Gotcha, I'm intrigued wiki says "SPDC allows for the creation of optical fields containing (to a good approximation) a single photon. As of 2005, this is the predominant mechanism for an experimenter to create single photons", do you know of a simple explanation on how single photons are generated using the crystal + laser?
- fsh 7y agoMost quantum optics experiments are done by simply attenuating laser pulses until they have on average much less than one photon per pulse. This way the probability of having more than one photon is very low (at the cost of reduced count rates since most pulses don't contain any photons). These pulses can then be used to create entangled photon pairs using SPDC. There are also several ways of creating pulses that contain exactly one photon, but this is way more complicated.
- lisper 7y agoIt's not enough to produce entangled photons, you also have to be able to detect them individually. That's the expensive part.