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Scientists Break Quantum Entanglement Record At 18 Qubits (zmescience.com)
hackingbear writes: Researchers at the Chinese University of Science and Technology have demonstrated stable quantum entanglement with 18 qubits, surpassing the previous world record of 10, also held by the same team. This represents a step toward realizing large-scale quantum computing, according to a recent study published in the journal Physical Review Letters. Physicist Pan Jianwei and his colleagues achieved the new record by simultaneously exploiting three different degrees of freedom-paths, polarization and orbital angular momentum of six photons, the fundamental particle of light. The outcome combination resulted in a stable 18-qubit state. Full control over the number of entangled particles determines the fundamental ability for quantum information processing, according to the study. There are early-stage quantum computers out there that argue more qubits -- such as IBM's 50-qubit machine and Google's 72-qubit Bristlecone, but in those cases, the individual quantum states of the qubits aren't (fully) controllable. "The team's next step will be to realize a 50-qubit entanglement and manipulation," according to Wang Xilin, a member of the team. The same research team also held the world record on quantum communication distance as well as operating the world's first quantum communication satellite.
It means the writer believes that people who understand the phrase "simultaneous exploit of three different degrees of freedom-paths, polarization and orbital angular momentum" might not know what photons are.
No sig today...
The bigger the system you can stabilise, the bigger the questions you can answer immediately (i.e. factorise this 2048-bit number), and you can answer ALL such questions in that same timeframe (so once you can break one 2048-bit key instantly, you can break them all instantly).
That is simply not true.
http://www.quantumforquants.org/quantum-computing/limits-of-quantum-computing/
Probably. With the progress they are making, they will most assuredly not deliver in the next 50 years and without any fundamental breakthrough (not on the horizon and cannot be planned or forced) it may take 1000 years or longer for this to become useful at all. At the moment, they seem to be able to add about 1 Qbit/year for actual computations. And the impression that this may scale sub-linear is not off the table at all.
Time for the hype to die down, there is nothing useful this technology can do.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
QC is limited only by the size of a stable system that you can build. But the stable systems you can build give you any/all/every answers IMMEDIATELY.
Looks like you are the clueless one here. No, it does not give you answers immediately at all. You still have to feed in the data and do computation steps and you have to do this slowly and carefully to avoid decoherence. And if it decoheres, you have to do everything again from scratch. And due to noise, you either have to add a lot of error-correcting steps or run it for a lot of times. There is nothing "immediate" here.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
The answer is immediate. O(1). Not O(n) or worse as in any classical system.
I'm not sure how you could have come to believe this ... but it's incorrect. Quantum computers can use algorithms that scale better than classical ones - say, scaling as O(n^2) rather than O(e^n) - but they don't generate an answer *immediately*.
For example, Shor's algorithm for factorisation runs in O((logN)^2 * loglogN * logloglogN) time, while the classical general field number sieve which does the same thing runs in (roughly) O(e^(1.9 * (logN)^0.33 * (loglogN)^0.66) time. That's a massive improvement - going from subexponential to polynomial time - but it's still not instant.