Noise can improve quantum computing, says ANU scientist Here’s a nice paradox: since noise gets in the way of quantum computing, cure it by adding more noise. That startling proposal is the work of a team led by the Australian National University’s Dr André Carvalho, along with collaborators from Brazil and Spain. Noise is normally treated as the enemy in quantum-level experiments …
"This means, simply, that if a qubit starts in a “1” state, it will eventually emit a photon and fall to a “0” state...
Dr Carvalho’s solution is two-fold: first, to add noise (as photons, using a laser) back into a qubit before the state-decay takes place..."
So, essentially, in this way qubits act similarly to DRAM, requiring a refresh (as opposed to NVRAM). That's probably simplifying a bit, but I'd hope it's a good analogy for this crowd.
Of course, the mechanism to do this refresh, and the second part about the added noise essentially keeping the quantum uncertainty alive is well beyond my mortal ken...
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If you detect all interaction with the 'outside world' (== absorbed and emitted photons), then you remove all decoherence: by monitoring the environment, you explicitly treat the interactions with the environment, hence there are no unexpected (nosy) interactions.
Of course, this just creates a bigger box of a quantum system that you have to control and manipulate. The environment is now part of your quantum computing system. The bigger system will have more interaction with the environment (the photon detectors have their own noise, the lasers you use to re-pump the quantum system also bring noise), hence the problem is shifted one level out from the initially considered inner system. Whether this will help to perform real-world quantum computations is not clear.
Just to boggle you mind: What happens if you take the whole universe into your considered quantum system? No unexpected interactions with other matter can occur if all matter is taken into the system. So we might be basically performing one humongous quantum simulation to determine the fate of life, the universe, and anything. From the inside, of course, we wouldn't ever be able to tell, so don't give up on free will quite yet.
Seems Grizabella escaped from the box after some statistically improbable quantum fluctuations and was last seen skiving off with Deuteronomy up to the Heaviside Layer:
"...Up up up past the Russell Hotel,
Up up up up to the Heaviside Layer.
Up up up past the Russell Hotel,
Up up up up to the Heaviside Layer.
Up up up past the Jellicle Moon,
Up up up up to the Heaviside Layer.
Up up up past the Jellicle Moon,
Up up up up to the Heaviside Layer.
The mystical divinity of unashamed felinity
Round the cathedral rang 'Vivat'
Life to the everlasting cat!"
(Apologies to T.S.E.)
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