Does polarization support developing super-fast computers
Light, and its polarization (filter e.g. sunglasses), can be used to transfer information in quantum computers.
Fact is, electrons have the two possible states “spin up” and “spin down”, equally expressed with |up⟩,|down⟩ or |0⟩ (ket notation),|1⟩ (ket notation). Similarly for photons – our light. The only difference is, that the polarisations states – referencing Heisenberg’s Uncertainty Principle- horizontal and vertical, labeled with |H⟩,|V⟩ or |0⟩,|1⟩.
Take away: photons are Qubits with respect to their polarization
Linearity & Correlation
Now the second important part. Quantum computing is linear. Wow, what does this mean?
- On one hand, it is like the music scale, but once trigger and played in one pass (link). A sequence of operations – our polarization filter – followed by one finalizing state read. Also the “String theory” is correlated to that. Like tones, those strings move and vibrate at different frequencies and may interfere.
- On the other hand, it states the linear (algebra) superposition (aka polarization). Superposition as the position on the spheric space ψ = α|0⟩+β|1⟩ – complex number α as the angle between x and y dimension and the complex number β as the z angle (0 to 180 degrees). Nicely illustrated by the Bloch-sphere (link). If it is measured it falls into a fix position 0 or 1 (the more probable one). This is known as Wave-particle duality (link) and allows calculations with a defined (final) classical binary state.
Also consider:
- The Max Born rule – not the film – boils everything down to a probability view. How much passed through or is blocked represents a probability – from 0 to 1, also 0% to 100%. The symbol, psi ψ, mathematically represents all the possibilities that a quantum object (our photon) can take. Or in Borns words “[the wave function ψ] gives the probability of a definite course of the mechanical process”.
- It is the tendency that one thing depends on another – also consider the https://en.wikipedia.org/wiki/Bayesian_inference. Or in the quantum world called entanglement. If the processing stream is split – consider the “music scale” analogy – the split parts are entangled. If you change one, also the other changes.
Applied operations
The law of superposition applies to the wave function. Any linear combination (a simple mathematical “+”) of two wave functions gives one new wave function. Also compare https://en.wikipedia.org/wiki/Fourier_transform
In a nutshell:
- Merge of at least two waves. For illustration purposes, yellow and blue result in green. Also compare the single/ double-slit experiment (link).
- Calculations consequently performed via a sequence of polarization filters (aka merges, depending on previous merges/ changes) (link).