Uses photons!
The key experiment/phenomena that sets the basis for photonic quantum computing is the two photon interference experiment.
The physical representation of the information encoding is very easy to understand:
- input: we choose to put or not photons into certain wires or no
- interaction: two wires pass very nearby at some point, and photons travelling on either of them can jump to the other one and interact with the other photons
- output: the probabilities that photos photons will go out through one wire or another
- https://youtube.com/watch?v=7wCBkAQYBZA&t=1285 shows an experimental curve for a two photon interference experiment by Hong, Ou, Mandel (1987)
- https://youtube.com/watch?v=7wCBkAQYBZA&t=1440 shows a KLM CNOT gate
- https://youtube.com/watch?v=7wCBkAQYBZA&t=2831 discusses the quantum error correction scheme for photonic QC based on the idea of the "Raussendorf unit cell"
- Photonic quantum computer
- Quantum computer physical implementations
- Quantum computers as experiments that are hard to predict outcomes
- Quantum error correction
- Quantum logic gates are needed because you can't compute the matrix explicitly as it grows exponentially
- Spontaneous parametric down-conversion
- Two photon interference experiment
- Why it is hard to simulate quantum systems?