Cnot

[lorka]

Could somebody tell me whether or not a CNOT gate has actually been built or not?

Thanks,

lorka

[jvangael]

I believe there are several CNOT physical realisation up to today. One of them:

http://www.electronicsnews.com.au/articles/61/0c01b761.asp

Jurgen

[meteor]

Yes, Controlled-NOT gates have been made, even teleported, and several quantum circuits implementing them studied. Here's one proposed quantum circuit, a variation of the "quantum multiplexor circuit", using CNOT gates
http://arxiv.org/abs/quant-ph/0410066
Another quantum circuit using CNOT gates is the Brassard teleportation circuit
http://beige.ovpit.indiana.edu/B679/node72.html

[Mk]

The Japanese invented them.