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IBM will soon launch a 53-qubit quantum computer
- criddell 7y ago> Some of these have started to use the available machines to work on real-world problems, though the current state of the art in quantum computing is still now quite ready for solving anything but toy problems and testing basic algorithms. Isn't that a contradiction?
- foofoo55 7y agos/now/not/
- criddell 7y agoThat's how it is in the article so I left it as-is. I tried to leave a message about the typo, but it was asking me to create an account so I gave up.
- sp332 7y agoThe first part means that anyone can sign up and run a program on a real quantum computer. The second part means that they're not powerful enough to be useful yet.
- hannob 7y agoYes.
- nickpeterson 7y agoI don't keep tabs on quantum computing at all, but I get the distinct feeling that it isn't going to turn into anything important. Is there any reason to believe this will be relevant to regular developers in the next 20 years?
- vasco 7y agoI'm also very unaware of actual papers coming out of the field but it does seem like it'll serve similar purposes to FPGA type work, where if you need to optimize a certain workload and you have the budget, you'll probably offload some code paths to a quantum computer / expansion-card. I do get the feeling that the "regular developer" won't have to deal with it or think about it any time soon.
- roblabla 7y agoQuantum computing won't be relevant to most regular developers, in the same way machine learning isn't relevant to most regular developers. Quantum computing might end up being useful for certain niche use-cases, such as heavy number crunching that can be made faster via quantum algorithms. As to whether it will be usable within 20 years, time will tell.
- XJ6 7y agoAnd just as every company is trying to work out how to "use AI" they'll be trying to work out how to "use Quantum" in future, with all the typical buzzword bullshit that comes with it.
- deleted 7y ago[deleted]
- codesushi42 7y agoWhat is a "regular" developer then?
- pulse7 7y agoIt depends on the number of qubits they will achieve. The larger the count, more relevant will it be. But if it stays low, the impact will be low...
- TallGuyShort 7y agoYeah I was impressed that they had a fleet of quantum computers this size. Turns out I'm well over a decade behind on my sense of how many qubits one should have...
- vamos_davai 7y agoI don't really understand quantum computing, and hopefully someone would shed light and let me know if my understanding is wrong. Isn't a qubit similar to a transistor that can hold more than 2 states and the implication is that it'll be faster than current SIMD operations?
- roywiggins 7y agoIt's weirder than that. Some quantum algorithms offer a big-O speedup over classical ones. Shor's algorithm is O(n), which is categorically faster than any known classical algorithm for integer factoring. It's polynomial time, whereas the fastest classical algorithm is subexponential. For every subexponential algorithm, there will be some n at which Shor's algorithm will be faster, and some slightly higher n at which it's much, much, much faster. https://en.wikipedia.org/wiki/Shor%27s_algorithm https://en.wikipedia.org/wiki/Shor%27s_algorithm
- seamyb88 7y ago> Isn't a qubit similar to a transistor that can hold more than 2 states ... Not really. From an information theory perspective, holding two states is the most efficient way of computing. Or at least, there is no speed-up gained from doing computations in any other base than 2. Quantum computers can be in both states at the same time (as far as that interpretation of quantum mechanics goes). So, if you keep the qubits all in this superposition state, you can calculate multiple things at the same time.
- mrob 7y ago>From an information theory perspective, holding two states is the most efficient way of computing. Assuming the cost of operations on each digit is a multiple of its number of states, the most efficient base for computing with arbitrary numbers is 3, which is the closest integer to the optimal base e: https://en.wikipedia.org/wiki/Radix_economy https://en.wikipedia.org/wiki/Radix_economy https://en.wikipedia.org/wiki/Ternary_computer https://en.wikipedia.org/wiki/Ternary_computer
- 7y ago
- nharada 7y agoIs there a generally accepted crossover point where quantum computers will start outperforming classical computers on the same tasks? I was under the impression it was somewhere around 100 qubits, but I'm sure there are caveats around noise and stability as well, not just number of qubits.
- LeonM 7y agoThis threshold is commonly referred to as quantum supremacy. It could be that IBM just passed that threshold, but I'm by no means an expert on this. https://en.wikipedia.org/wiki/Quantum_supremacy https://en.wikipedia.org/wiki/Quantum_supremacy
- zamalek 7y ago> It could be that IBM just passed that threshold I don't think they have just yet. There is a simulated QC on conventional hardware with around 50 qbits. We are close, though, it might still happen this year.
- reikonomusha 7y agoBut even with 50 qubits, the amount of time per operation—if simulated classically—is at least a million+ times slower than what it would be for a quantum computer. This is like comparing disk to L1 cache. Does that count for supremacy? Mathematically, no. Does it count for some kind of advantage? Yes.
- LanceH 7y agoThat point in time is, "tomorrow".
- just_one_time_ 7y agoBetter to be safe, I always say 6-9 months away, at MOST.
- The_rationalist 7y ago
- ptah 7y agowhat workloads would i run on these?
- krastanov 7y agoOn this particular one, probably only research code that tests various small scale optimization algorithms and tests ways to "calibrate" the hardware. In a couple of years, on the next gen of such hardware, the hope is to run things like optimization algorithms and chemistry simulations that just begin to outperform what is possible with classical hardware of reasonable size and cost.
- ptah 7y agoso it will eventually run stochastic gradient descent faster than GPU?
- krastanov 7y agoThe short answer is no. The long answer is much more interesting. The premise of your question is a bit misleading. Quantum computers do not run classical algorithms faster, rather they run algorithms specifically designed to take advantage of the quantum coherence. For many tasks this does not provide an advantage. For some very special (and occasionally useful) tasks, the advantage seems to be exponential. Simulating quantum mechanics (as in chemistry, material design, drug design) is one of these tasks. Some linear algebra tasks are also faster. Lastly, some researchers are hopeful that novel gradient-free optimizations algorithms exist for quantum hardware, but this is a bit more controversial.
- Hongwei 7y agoI live/work in Waterloo and regularly ask a favour of the Quantum Nano Centre folks at UWaterloo for a tour. Every time I look at the "computer," housed in a gigantic facility where each qubit has its own liquid nitrogen cooling unit and who knows what else plugged into it, and think to myself - I'm staring at the vacuum tube of quantum computing. Yes, you can scale up vacuum tube computers to solve meaningful tasks, but it was barely more cost effective than human "calculators" except for specific applications. I think the same analogy applies for modern day quantum computers and classical computers.
- WilliamEdward 7y agoAnd much like vacuum tube computers were, early quantum computers are a necessary step towards the advancement of computing.
- goatlover 7y agoComputing is still advancing with silicon.
- kens 7y agoI think you're being too hard on vacuum tube computers. There were a lot of vacuum tube computers and they were pretty successful. Electromechanical computers like the Harvard Mark I would be a better comparison; they worked, but were too expensive and slow to be more than one-off systems.
- Hongwei 7y agoGreat point, your analogy is better.
- jxramos 7y agoGreat analogy!
- equalunique 7y agoIn 2018 at my local makerspace, one of the guys behind this[0] research did a talk about "noise interference" in quantum computers. He did a great job of explaining how conventional electronic components are unsuitable for the precise and isolated requirements of quantum computing. What really left an impression was the remark he made about error-checking. It was something like, the then-current state-of-the-art qbit tech requires eight qbits to error correct every one qbit to at the same level current x86 computers are error-corrected, meaning that a viable quantum computer is a very, very long way away. [0] https://physics.aps.org/synopsis-for/10.1103/PhysRevD.96.062002 https://physics.aps.org/synopsis-for/10.1103/PhysRevD.96.062...
- q_eng_anon 7y agoError detection vs. error correction are very different things. It's true that many physical qubits (and a proper error correction scheme) are required to implement a single logical qubit. But once a valid design for a single logical qubit (device, error correction, etc.) is realized, the limits of scaling the entire system change completely (infinite t1 of each qubit means you don't NECESSARILY have to have all of your qubits on the same device...)
- cma 7y agoI'd imagine that though error-checking is the biggest hurdle, we don't need quite the same level of error checking as an x86 computer for applications like breaking cryptography, since you can verify the result quickly on a classical computer.
- reikonomusha 7y agoAlongside the development of quantum hardware, which has ever-growing qubit numbers and ever-increasing fidelities and coherence times, there’s also software that’s getting more and more sophisticated. Most quantum computer providers have their own APIs for programming their machines [1,2,3]. Python seems to be the popular choice for these APIs. But one piece of software I’ve been particularly interested in, and indeed contribute to, is Rigetti’s open source optimizing compiler called quilc [4,4’], which is a sort of a GCC/Clang for quantum computers. It’s the only open-source compiler of it’s kind. They also have a high-performance simulator [5], which is used sort of like a debugger. (Perhaps surprisingly, both are written in Common Lisp.) What is very useful about the compiler is that it is retargetable, and can compile for even IBM’s architectures of tomorrow. You just give it an “isa” at the command line describing how many qubits it has, how they’re connected, and which gates they support, and quilc will happily compile and optimize your program for that architecture. [1] Rigetti’s pyQuil https://github.com/rigetti/pyquil https://github.com/rigetti/pyquil [2] IBM’s Qiskit https://github.com/Qiskit/qiskit https://github.com/Qiskit/qiskit [3] Google’s Cirq https://github.com/quantumlib/Cirq https://github.com/quantumlib/Cirq [4] quilc https://github.com/rigetti/quilc https://github.com/rigetti/quilc [4’] quilc at FOSDEM https://youtu.be/qwfMzzKJDXI https://youtu.be/qwfMzzKJDXI [5] quantum virtual machine https://github.com/rigetti/qvm https://github.com/rigetti/qvm
- Iwan-Zotow 7y ago> It’s the only open-source compiler of it’s kind. Huh?!? Microsoft Q# was open sourced this spring, I believe
- reikonomusha 7y agoThat is a language and programming framework, not an optimizing compiler. (To my knowledge, it also doesn’t have any real quantum computer backends.)
- 1000units 7y agoWow, they don't have a compiler for their "language and programming framework"? That's a pretty embarrassing oversight.
- scottlocklin 7y agoI wonder if you can factor the number 15 on it yet. Actually I don't wonder; I know for a fact that they can't do it.
- q_eng_anon 7y agolmao they did this 2 decades ago: https://arxiv.org/pdf/quant-ph/0112176.pdf https://arxiv.org/pdf/quant-ph/0112176.pdf
- scottlocklin 7y agoNo, actually they didn't. The Shor algorithm applied to n bits is 72 * n^3 applied gates; for 15 that's 4608 gates; and that's leaving out quantum error correction which would require even more gates. This has never been done. The result you cite: they don't even consider those early NMR "computers" to be quantum in any meaningful sense. They're avogadro computers.
- deleted 7y ago[deleted]
- q_eng_anon 7y agoooookay a more recent demonstration: https://arxiv.org/pdf/1804.03719.pdf https://arxiv.org/pdf/1804.03719.pdf you said the number 15 was never factored on a quantum computer - this is false. You can run as many gates as you want - go ahead and run 4608 gates in qiskit right now - the measurements will be random but you can do it. IDK where you got that equation for the number of gates but it's probably for the general case - doesn't take into account the fact that different gate sets can be used to reduce the total. Also confused on the error correction part - the whole point of error correction is to make the coherence time independent of the number of 'gates' in your circuit - so yeah with error correction you get more gates but you also get an effectively infinite coherence time...
- scottlocklin 7y ago
- doctoboggan 7y agoQuestion from someone who only knows what is in the popular press: I've read articles that debate the existence of any quantum computers. Are we past that now, or are there people out here that would question whether these are real quantum computers?
- krastanov 7y agoNobody has claimed yet having anything that is a scalable error-corrected quantum computer (or whoever has claimed it was never taken seriously). But we are working hard on getting there, and this 53-qubit "quantum computer" is indeed a machine that can compute things and it uses quantum effects (so it is a "quantum computer"). It is not a "general" or "error corrected" or "scalable" quantum computer. The comparison in sibling comments is very apt: this, and other research hardwares of today, relates to general "useful" quantum computers the way a bunch of vacuum tubes relate to the first classical CPU.
- malms 7y ago"IBM" Next
- deleted 7y ago[deleted]
- jedberg 7y agoIt's interesting to me how long this has taken to go from research to even the most limited commercial applications. My friends were writing quantum computer compliers and frameworks in grad school in the 90s. They had to start by building a quantum computer simulator, since no QC existed yet to test their stuff on. I think however that once the hardware part is solved, the software part will move quickly, since people have been working on the software since long before the hardware existed.
- legohead 7y agomy brother worked at Seagate in the 90s and would tell me about their research into chemical memory and "holocubes", and how they felt it was just around the corner. yet here we are, still using the same old hard disks. we have SSDs now, at least.
- tpmx 7y agoCan existing quantum computers be considered evidence for parallel universes? https://physics.stackexchange.com/questions/164500/can-existing-quantum-computers-be-considered-evidence-for-parallel-universes https://physics.stackexchange.com/questions/164500/can-exist... (tldr: noone knows)
- knzhou 7y agoExisting quantum computers are evidence against a strawman of the Copenhagen interpretation, which is "everything the size of an atom or smaller is quantum, everything bigger is classical, and whenever the two touch, a collapse occurs". This is of course silly and arbitrary, and has been known by physicists to be false for nearly as long as quantum mechanics has been around; there are plenty of quantum effects that involve objects bigger than an atom. Quantum computers are simply another example. Any genuine interpretation of QM will agree on what a quantum computer outputs, because by definition, interpretations are ways of changing the words you drape around a calculation, not the result of the calculation itself. So quantum computers don't support or oppose any genuine interpretations. They only oppose strawmen.
- galaxyLogic 7y agoWhen using a quantum computer, what is the act of "observation" that collapses the qubits to 0s and 1s? Does the observer have to be a human?
- fsh 7y agoHow the measurement is done depends on the physical implementation of the qubit. For example the state of the qubit could affect the resonance frequency of a coupled microwave cavity which can be measured using RF techniques. Obviously at some point the experimenter has to check the result of the measurement, which makes the question what would have happened without a conscious observer impossible to answer.
- galaxyLogic 7y agoVery interesting. Then does the observation of one qubit collapse them all at the same time, or is it possible to decide to read just one qubit at a time?
- UnFleshedOne 7y agoAs I understand it "observation" is any interaction that leads to decoherence. No complex neural wetware required.
- galaxyLogic 7y agoSo no Schrodinger's Cat? The cat is the observer! Sounds natural and obvious, so why haven't I heard this solution to Schrodinger's Cat many times before? Why is Schrodinger's Cat still considered a problem worth discussing ?
- UnFleshedOne 7y agoSchrodinger's Cat is Schrodinger's way of saying Copenhagen interpretation is probably wrong I think. That was an absurd example that got a life of its own.
- 7y ago
- szczepano 7y agoI think scientists need other material for managing quantum state to get some real progress.
- danschumann 7y agoSeeing such a contraption makes me remember that "digital" stuff is actually natural laws of electricity, and whatnot, being applied to computer. It also makes me think of one day the biological computers that will come about, and how people will think it's crazy to "make" a computer when you can just grow one.
- rubyfan 7y agoWhat are the actual practical use cases for quantum computers right now?
- bufferoverflow 7y agoWriting and selling books on how to program quantum computers.
- Causality1 7y agoSo the big deal about quantum computers is how they're really fast at solving certain very specific problems, but I've never seen numbers about how much better at solving those problems they are than conventional computers. I realize they work on completely different principles but it should be hypothetically possible to make a normal computer solve the same problem even if it were to take a decade to do what a quantum computer can do in a microsecond. So, how much faster are they? A million times faster? A trillion? A googol times faster?
- joak 7y agoIt depends on the problem. Let's take the 2048-RSA integer factorization problem. Back of the envelope calculation: The best classical algorithm takes 10^34 steps. The fastest computer on earth _Summit supercomputer_ runs at 200 petaflops (2.5M cores, ~10^6x faster than your desktop computer) Actual quantum computers perform at 1 million operations/s per qubit for 2048-RSA, Shor's algorithm needs 4096 non-noisy qubits (we are far from that) and run in 10^7 steps So for this particular problem: Best classical computer (as of today): 1 billion years An (hypothetical) quantum computer: ~10 seconds Yeah, a trillion times faster...
- Causality1 7y agoInteresting, thank you. It makes me wonder if we'll ever find a way to make quantum computers do "easy" math as well as they do difficult math, if we'll ever have general-purpose computers that do their arithmetic and rendering on a quantum processor instead of a transistorized one. Is it even hypothetically possible for a quantum computer to do something like render a web page using less electricity than a conventional cpu?