I'v read published books, articles and papers about Quantum-Computing.
I found that all the materials I've seen are, instead of describing quantum gate from basic physics to abstraction, trying hard to avoid talking about the implementation details of quantum-gates.
I firstly questioned myself: Am I searching in the wrong area where only formal mathematics are concerned?
But I found those papers and books do have explained ion-traps, optical-switches and even laser-fibre in great detail.
When it comes to quantum-gates they claimed to have used in their research, only matrices, equations, formulations and black-box components are shown.
We all know about the unitaries and matrix computation. But if you print a quantum-gate matrix operator on an A4-paper, that ain't going to do anything when photons or electrons are thrown to it.
So, does anyone know what is a quantum gate, concretely so that I can know:
- Is Quantum Gate a device using magnetic field to do element arithmetics?
- Is Quantum Gate a device using laser-beam?
- Is Quantum Gate a device using metal wire?
- When scientists happily multiply eigenstates by observables, do electrons collide in the gate when "multiplied"?
Thanks in advance.