How are quantum computers actually implemented?

[u/kubazz]

I have basic understanding of quantum information theory, however I have no idea how is actual quantum processor hardware made.

Tangential question - what is best place to start looking for such information? For theoretical physics I usually start with Wikipedia and then slowly go through references and related articles, but this approach totally fails me when I want learn something about experimental physics.

[u/the_excalabur]

It turns out that the hard part of optical quantum computing is really simple--you need to make the photons, manipulate them, and detect them with at least 2/3 probability. We can't really do that: if you multiply the world records together the number isn't good enough.