Talk:Quantum computing

Contradictory statements regarding space?

The introduction suggests that simulating an n-bit quantum computer on a classical TM requires 2^n discrete states. But doesn't this contradict the later statement that QBP is a subset of PSPACE? (Erniecohen (talk) 15:50, 14 October 2012 (UTC))

It's just an example of how a classical computer could simulate a quantum computer. It doesn't mean that it's the only way to do so. --Robin (talk) 15:55, 14 October 2012 (UTC)

The problem is that the way that it is written, it strongly implies that quantum computing provides a space advantage, which is just false, so the 2^500 crap should just be removed. The relevant connection between the models is just that a classical TM can simulate a quantum computer with a polynomial blowup in space, but is strongly believed to require an exponential blowup in time. — Preceding unsigned comment added by Erniecohen (talk • contribs) 16:04, 14 October 2012 (UTC)

I wasn't aware of this. Do you have a reference? Skippydo (talk) 19:27, 14 October 2012 (UTC)

Has this been resolved? It seems odd to me in any case to say that 2⁵⁰⁰ complex values is equivalent to 2⁵⁰¹ bits (does this mean that there are only four complex values available)? W. P. Uzer (talk) 12:27, 2 February 2014 (UTC)

Given these two objections, I've commented out the sentence in question for the moment. W. P. Uzer (talk) 08:50, 4 February 2014 (UTC)

How does it work... really!

It seems like this article would benefit from explaining how quantum computers work physically. I assume they manipulate individual atoms, but how?

Comment so that archiving will work. (Answer already in article.) — Arthur Rubin (talk) 12:28, 31 May 2015 (UTC)

and where is the critique section of this article? — Preceding unsigned comment added by 75.163.218.83 (talk) 05:12, 4 September 2015 (UTC)

Announcing new results

/(

"..(-2,334)‎ . .(Sorry, Wikipedia is not the place to announce new results. See WP:OR) .." - and wghere, WHERE is such place, for new ideas, announcing and discuss them, developing them more, and .."brainstorming",maybe ?, or just constructive discussion.. yap, according that "WP:OR" document, if we all would strictly managed by it, it would be means, - all advancing, all scientific and technical development would be almost stopped, in fact.. bcos no one would know about any new ideas, new results, new.. anything.. :/(

\( — Preceding unsigned comment added by Martin Hovorka (talk • contribs) 19:30, 2 September 2013 (UTC)

deleting of new idea announcing

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hmm... not even just announce,a bit, any new idea (imho quite promising, relevant, and ..perspective.., this my multi-Sieves/Sifthering Q.C. Idea) ..even nor get,make a little advertisement,and spreading-out, for this new,constructive,fresh-brigth concept.. :\( (..but it is, and always was, my idea, trying make Q.Computing with this concept of sieve, /sifter approach,/concept(sieving) — Preceding unsigned comment added by Martin Hovorka (talk • contribs) 20:57, 2 September 2013 (UTC)

It's your fault for announcing the idea here. Doesn't everyone know by now that, if you want to patent an invention, you must do so within one year of publication. Under the new US patent law, publication may make it impossible to patent it at all. (And, yes, posting it on Wikipedia constitutes "publication".) — Arthur Rubin (talk) 21:07, 2 September 2013 (UTC)

other wiki for discussing quantum ideas

There is a common misconception that people who support the WP:OR policy are people who don't want to see any original research on any wiki.

Actually, some of us *do* want to see original research on a wiki -- but on an appropriate wiki where such research is on-topic, not just any random wiki.

There are over 10,000 English-language wiki. Pretty much any topic you can think of is on-topic at at least one of them. In particular, quantum computing seems to be on topic at several wiki including http://quantiki.org/ , Wikia: 3dids, http://quantum.cs.washington.edu/ , http://wiki.qcraft.org/ , http://c2.com/cgi/wiki?QuantumComputing , http://twoqubits.wikidot.com/ , http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics , http://www.physics.thetangentbundle.net/wiki/Quantum_mechanics , etc.

--DavidCary (talk) 04:30, 15 January 2014 (UTC)

Quantum supercomputer

Is it really the case that a quantum computer is "also known as a quantum supercomputer"? I've never seen that usage before & suspect it should be deleted. --24.12.205.104 (talk) 00:48, 6 January 2014 (UTC)

how can a quantum computer create:

there is a requirement for a new index system there is not any part of quantum that will give 0 zero nothing a value my understanding is quantum is the least amount of energy required to create change within a structure of mass. E=Mc2. no structure of Energy or mass within any environment can change unless another structure of energy or mass has the ability to influence or interact with that unit of structure. 0 zero nothing does not have the ability to interact. relativity and quantum will only reconcile when relativity recognizes 0 zero nothing has no potential to exist or create. lets look at the potential of a quantum computer. 0 and 1 cannot create a interaction of change . why. 1 has a value and therefore has a potential structure 0 within classical mechanics will only ever have no structure and therefore cannot interact therefore. only value 0 or 1 or any other quantity of 0 or 1,s can represent is a unique value. for quantum to create a computer language o zero nothing cannot be a partner, The singularity of 0 zero nothing will never evaluate change or interaction. compound mathematics or very basic energy/mass interaction. even a higgs boson is a unit of energy that has an exact mass value as the potential of a velocity to transport at the speed of light for a period time it environment allows.Cubedmass 01:22, 26 January 2014 (UTC) — Preceding unsigned comment added by Cubedmass (talk • contribs)

Cubedmass: ?? — Arthur Rubin (talk) 19:12, 2 February 2014 (UTC)

misc suggestions / solving chess - programming the universe - more intuitive intro

I think it would be great if the article mentioned solving chess as something that quantum computing would allow.

I also think Seth Lloyd's book "Programming the Universe" should be referenced somewhere.

The first sentence I think is too technical. It tells precisely what the term means in physics, it doesn't give any layman sense as to what quantum computing is. It almost sounds like: "Quantum computing is a process where computers use quantum systems to do computing". A layman will want to know something basic immediately like the fact that quantum computers are extremely fast and will soon be replacing standard computers.

...My 2 cents. Squish7 (talk) 00:40, 26 March 2014 (UTC)

Page title should be "Quantum computing"

To my sensibility, this page title is all wrong, or maybe not entirely - simply we have to create a more general page about more "general aspects and applications of quantum computing" like some quantum transistors that work partially as "quantum computers" but are cheaper to produce.

Computer science is no more about computers than astronomy is about telescopes. — Edsger Dijkstra

Additionally, Google

 "quantum computing" -"quantum computer"

gives 2,440,000 results

 -"quantum computing" "quantum computer" 

gives 961,000 results, so one appears without the other significantly more often. — MaxEnt 05:10, 5 May 2014 (UTC)

 Done —Ruud 18:01, 21 December 2014 (UTC)

Quantum games

A collection of IPs is adding an announcement of "the first quantum computer game". Even if this were sourced to a reliable source (it's not at all in the reference specified, which is a blog [not even a blog entry], and all I can find is a blog entry pointing to the announcement by the creator), would it be appropriate for the article? — Arthur Rubin (talk) 05:49, 21 May 2014 (UTC)

The announcement by the alleged creator is not a reliable source, either. — Arthur Rubin (talk) 10:39, 24 May 2014 (UTC)

strongly need th consider of change the title of this wiki-page from Q. "Computer" to "COMPUTING"

can be title of whole wiki-page re-turned to be Quantum COMPUTING, as it was before ? as "Computing" is far more fitting, more overal term for this wiki page´ topic, as just 1 concrete THE "computer") — Preceding unsigned comment added by 78.99.236.255 (talk) 17:49, 23 July 2014 (UTC)

 Done —Ruud 18:01, 21 December 2014 (UTC)

Invented When?

You should discuss when Quantum computing was invented and the purpose of Quantum Computing at the time.

2601:C:5600:27B:C92A:EEBE:6758:C647 (talk) 17:52, 18 January 2015 (UTC)Johnnie DeHuff

The basic idea occurred as early as 1965, in Feynman Lectures on Physics,vol. 3 when Feynman mentioned that it was frequently faster to do the physical experiment than to do the mathematical computation. In other words, use a physics experiment as an analog computer. --Ancheta Wis   (talk | contribs) 17:56, 1 February 2015 (UTC)

Minthreadsleft

Why is it 10? If we're going to archive, 5, or possibly 2, would be better. I already archived one thread which was (potentially) about the subject, rather than about the article. — Arthur Rubin (talk) 22:52, 4 May 2015 (UTC)

Changed to 5. I also "archived" 3 sections about alleged simulators of quantum computers, with no credible source. — Arthur Rubin (talk) 12:30, 31 May 2015 (UTC)

Three-bit Example?

It would be very helpful to see an example of a calculation or problem solved at the three bit level. Is there such a thing? JFistere (talk) 03:11, 15 October 2015 (UTC)

simplify intro!

The technical expertise in this article is very good, but way too technical at the intro. The intro should be a thesis statement especially for newbies. I'll back-read the terminology you used and see if I can glean enough to simplify the intro for you. No promises though!

By the way, are the states referred to in the article the spin of the qbit?

I just found a good nuts 'n bolts explanation here...http://www.wired.com/2014/05/quantum-computing/-Pb8bije6a7b6a3w (talk) 18:57, 26 October 2015 (UTC)

misleading lede

• "Given sufficient computational resources, however, a classical computer could be made to simulate any quantum algorithm, as quantum computation does not violate the Church–Turing thesis.[10]"

The whole article is currently very tech. Which is OK with me, even though I cannot understand it well enough to judge how correct it is... But it needs more content that is at a lower level. And it needs to be careful not to mislead readers who are not so tech. The above sentence currently concluding the lede is a prime example of content which is probably correct in theory but seriously misleading, particularly in the lede context. Most ordinary readers would not understand that "sufficient computational resources" includes unbounded quantities thereof, with no regard for feasibility. Yes, we may think quantum computers can only solve problems that a classical computer could solve if it was big enough and had enough time to solve. But there are many problems that would require using the entire universe to solve (organized as a classical computer) and still take longer than the expected life of the universe. If we think quantum computers will be able to solve some such problems (within feasible, limited, size and time constraints), we can fairly say there is a distinct difference in the problems these two classes of computers can solve, even if both classes of computers are only able to solve (all) Turing problems -- "given enough resources". I don't really know enough to know how the lede should be fixed -- but maybe I will Be Bold anyway, to get the ball rolling...-71.174.188.32 (talk) 19:11, 10 December 2015 (UTC)

Do I have this right?

I've been trying to ground myself in this subject in order to attempt a good thesis statement. The way I understand it, those qbits would explore all possibilities for a given expression - between two clock ticks of the quantum computer. Is that right? Pb8bije6a7b6a3w (talk) 00:28, 11 December 2015 (UTC)

Quantum vials / cartridge entanglement

Large multi-mono-atomic groupings cannot maintain cohesion for long. An old idea is to replace each atom with a vial (cartridge), so now each vial plays the role of a single atom, then we entangle the vials among each other. The problem is that particles inside a vial may entangle with other ones of the same vial (so now the vial doesn't act as a single atom), in order to avoid that we use few atoms on each vial [seems clever but it isn't for other reasons/small mistakes become important] and we cool each vial to make it almost a condensate [seems clever but it isn't for other reasons/each person should have a quantum computers, so superconductivity at room temperature is the only solution, not extreme temperatures]. Some reverberative NON-MEASURED laser radiation (the laser should allow different quantum states of oscillation that will be not revealed to us) will increase cohesion inside the mini vats. Sounds great but until now the result is randomness. Crucial details are under development. Akio (Akio) 00:28, 13 May (UTC)