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Fredkin Gate Breakthrough Brings Quantum Computing Within Closer Reach (pcworld.com)
An anonymous reader quotes a report from PCWorld: Quantum computers are based on atomic-scale quantum bits, or qubits, that can represent both 0 and 1 simultaneously. Realizing that potential, however, depends on the ability to build working quantum circuits. The quantum version of the classic Fredkin gate exchanges two qubits depending on the value of the third. It could be a key component of quantum circuitry, but because of the complexity involved, no one has ever managed to build one in the real world -- until now. Whereas the Fredkin gate typically requires a circuit of five logic operations, researchers from Griffith University and the University of Queensland used the quantum entanglement of particles of light to implement the controlled-SWAP operation directly. Essentially, the scientists demonstrated how to build large quantum circuits directly, without having to use numerous small logic gates. That, in turn, puts real quantum computers within closer reach.
I thought they were super-excited about the gate breakthrough and what it means for quantum computers.
Now if they bring some tits within closer reach, it'll get more attention.
I give up, quantum stuff makes sorcery sound logical in comparison.
Too bad Einstein's not still around; maybe he could find a more down-to-earth or simpler explanation. He seemed to be the only prominent one questioning that something seems really out of whack, as if we are missing a yuuuuuge piece of the puzzle.
He solved the ether weirditity by plugging in relativity. Similarly, maybe the probability and multi/ghostiverses games will fade away when the equivalent of relativity is applied to quantum stuff.
Maybe particles are like sperm in that when one photon is apparently emitted, there's really many particles emitted, and the first one to hit (react) shuts off the other particles so that they are invisible, almost like neutrinos, so that we don't detect them.
Thus, the interference pattern really *is* a wave; it only looks like a lone particle upon detection because the others cloak. Well, I'm rambling, but you get the idea: there's a BIG IDEA out there to be discovered...
Table-ized A.I.
Quantum computing will always be 20 years away. Getting anything practical work done on quantum computers is not likely going to happen in our lifetimes (unless you redefine 'practical work', of course).
-SR
Quantum computing can be described as a method, a technique, which allows for the computer for a given task to take a peak into the future and to read the answer from the future back to the present.
In my opinion, any real breakthrough or substantial achievements could and should be classified, because this matter is clearly a subject of the national security.
There is a lot to learn from the history. Did you know how Soviet military managed to spy and steal US nuclear secrets during WW2? Soviet military intelligence has been monitoring scientific journals. When Manhattan project has been started, all new scientific publications related to nuclear physics became classified and disappeared from scientific publications. Soviet military intelligence did notice disappearance, and accurately deduced that US has classified nuclear research, and started gigantic efforts to infiltrate and to obtain access to the nuclear secrets. True story.
For many years there were hardly any congruent discoveries published. Yes, quantum entanglement exists, nobody can explain why/how. Yes, quantum teleportation exists and has been proven scientifically. At the same time there is a consensus that Superluminal communication (faster-than-light) is considered impossible. Somehow I am sensing very similar trepidation as it relates to the flow of quantum computing news.
Well, it is and it's not.
You are welcome on my lawn.
Sadly no.
Quantum Physics is not science, more religion. Experiments to prove quantum entanglement prove it does not happen (e.g. the latest Delft experiment), and so Delft filtered the experiments for times of 'successful entanglement'. In other words filtering for the effect you're trying to prove then using those experiments as proof of the effect.
A photon of light never did change it's nature depending on the detector it hit. That change of nature never did propagate backwards in time and then forwards again to everything it interacted with. That was only ever the limits of the detector mapped onto the measurement.
An electron is never is all places simultaneously until detected. Where you detect it is just the limits of the detector mapped onto the thing being detected.
From discussions here, It's clear that many physicists don't even understand how a photo-multiplier works. Or understand that you could never have a zero energy gap detector because it would firing continuously. Hence you'll always fail to detect events below that energy gap in the detector.
Quantum computers (e.g. DWave) are analogue computers running annealing algo in hardware. They don't work instantaneously (no entanglement), they don't always get the correct result, (i.e. not in all states simultaneously, no quantum effect). Yet that is the properties you would expect.
"Yes, quantum entanglement exists, nobody can explain why/how."
Are you shitting me? They even put a filter in the circuit to select only the subset of experiments that will give them the result they seek! When you read the Delft paper they try to justify at length filtering the results. Which suggests they know its broken. The only entanglement between the two photons is the experimenters filtering!
It's the classic mistake, you have a flock of starlings, your detector can only see flocks and not individual birds. It sees the flock darting around, travelling faster than light, sometimes in two places, sometimes none. IT'S JUST THE ENERGY GAP IN THE DETECTOR MAPPED ONTO THE MEASUREMENT. If you could see the individual birds you'd understand.
Fire an electron at a screen containing two slits. Which of the two does it pass through? According to quantum theory, it explores both at the same time, but if you force it to choose by observing on the way past, you'll end up with two universes, one in which it passed through the left, and in another, the right. A more interesting question is what does the electron -feel- and -experience- as it makes that journey through the multiverse, through both slits at the same time? Since a single electron isn't sentient, it likely feels nothing, and cannot report on how it felt.
Scale the complexity up however, let more and more particles become entangled, and the question of subjective experience during that 'all paths at once' traversal gets more interesting. When you reach the level of the human brain, how do you answer the question of what an assembly complex enough to have a subjective experience (however the hell that arises, the hard problem) feels as it explores all possible paths of the multiverse at once?
Schrödinger's Quark
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