Talk:Quantum computing/Archive 1

message: Obviously quantum computing attracts a lot of attention, but with all due respect, this discussion page is a bit of a mess.
It would be much better if people used the separate sections of this Discussion (the table of contents is about half-way down...) to comment on particular bits of the article. Also there should be a separate section here for general quantum computing questions, as well as a lot of the speculation (i.e. things not related to the article's content).
I don't mean to whine, I just think we could be making much better use of the Discussion page to keep up a good article. Also, I would happily do some rearranging and filtering myself, I'm just afraid to hurt anyone's feelings by moving their comments...
-Svet - Tomatoman 20:26, 6 January 2006 (UTC)
thread_title:  Discussion tidy-up 

message: Some of the section which was there before (and is now called Initialization and termination), though written at a good level  I believe contains some innaccuracies, i.e.  on how the qubit registers are measured.  In fact, only a fixed register is sampled on termination.CSTAR 04:27, 6 Jun 2004 (UTC)
thread_title:  Further editing 

message: :: Now that we're at it, I think we should remove references to interprertation (Copenhagen, many worlds etc..).  Regardless of content, they shouldn't be in this article.  I haven't made an effort to understand whether what's writtem in the article makes any sense, so I won't pass judgment on that account_.   CSTAR 13:19, 18 Jun 2004 (UTC)
thread_title:  Interpretation 

message: Some of the edits by an anonymous user did increase readability, but I think calling entanglement or superposition a process is misleading.  Also Qubits  don't hold data -- they are measures of the size of data.  The register space is the actual container of data.  I tried to keep the spirit of the recent edits, but modifying what seemed misleading.  CSTAR 02:49, 2 Aug 2004 (UTC)
replies: text: Conditionals in the usual sense, no.CSTAR 20:08, 16 Aug 2004 (UTC)
thread_title:  Edits of 08/01/2004 

message: Hello,
I don't understand a lot about the technics of quantum computers. I would like to know if it is possible (at least in theory) to distributed quantum computing. it is possible to dream about a “quantum grid”, “quantum Beowulf”, “quantum@home?”
Thank you
? David Latapie 07:31, 25 Jan 2005 (UTC)
thread_title:  Clustered quantum computer ? 

message: The table in the section Bits vs qubits has glaring arithmetical errors: The absolute value of the complex numbers in the second column cannot possibly be equal to the numbers in the third column.  To fix this, pick eight angles
: \theta_1, \cdots, \theta_8 
and replace the kth row of second column by
: (\cos \theta_k + i \sin \theta_k) \times \sqrt{\mbox{third column}} 
--CSTAR 20:04, 11 November 2005 (UTC)
replies: text: Oops MY BAD, take that back... table is correct --CSTAR 20:09, 11 November 2005 (UTC)
thread_title:  Table is wrong 

message: Should this be put into the "computational models" category? - JustinWick 23:31, 16 November 2005 (UTC)
thread_title:  Computational models category 

message: The following paragraph seems wrong:
Consider a problem that has these four properties:
1.The only way to solve it is to guess answers repeatedly and check them, 
2.There are n possible answers to check, 
3.Every possible answer takes the same amount of time to check, and 
4.There are no clues about which answers might be better: generating possibilities randomly is just as good as checking them in some special order. 
...
These types of problems are classified as NP-complete, and many examples that are algorithmically similar to encryption cracking can be seen at List of NP-complete problems.
For me this seems not accurate. For example, Graph-Isomorphism has this kind of attributes, but isn't NP-complete.
Further more, I think that the most interesting part is whether BPP equals BQP or not. It is conjectured that factoring isn't in BPP, and this is the main reason for their power. sattath (talk)
:Good catch. Changed! My edit may be a little heavy on the language. If you would, please look it over. Skippydo (talk) 07:52, 23 March 2008 (UTC)
thread_title:  Use of NP-complete is wrong 

message: D-Wave demonstrated their 16 qubit quantum computer today.
 for more info, specifically World’s First Commercial Quantum Computer Demonstrated
I think the way this information was included should be changed or perhaps removed.  It sounds more like a PR release instead of something in an encyclopedia article. Very Quiet 13:50, 16 February 2007 (UTC)
thread_title:  breaking news - d wave quantum computer 

message: The article claims "Quantum computers only run randomized algorithms". I don't believe this to be a true statement. For example quantum error correction is completely deterministic in the sense that if the input is quantum data corrupted by noise within a certain threshold the output is fully determined. Sigfpe 21:33, 20 March 2007 (UTC)
replies: text: All classical deterministic algorithms are classical probabilistic algorithms (P is a subset of BPP). The probability simply happens to be one. Skippydo 13:48, 30 October 2007 (UTC)
thread_title:  Randomised? 

message: I was just wondering which sense of the word "dimension" was used in, when talking about the set of states. It would be n if it's the vectorial dimension of the states, 2n-1 if talking about the number of free functional parameters available as coefficients (amplitude and phase except the last one fixed by normalization), 2^something if talking about set theory with something as a function of n. Where does 2^n+1 -2 come from? Thanks a lot.
* See the section "Can quantum computers ever be practical for factoring?" in the archived talk page for a discussion of the dimensionality of the set of states.  The short answer is that a quantum register is described by 2^n complex numbers.  But the normalization constraint means that we actually need only 2^n-1 complex numbers.  Or if you want to talk about the number of real numbers needed, just multiply by 2 to get 2^n+1 - 2.Bjohnson00 17:52, 29 May 2006 (UTC)
thread_title:  Question 

message: Hi, I am working to encourage implementation of the goals of the Wikipedia:Verifiability policy. Part of that is to make sure articles cite their sources. This is particularly important for featured articles, since they are a prominent part of Wikipedia. Now this article has an extensive list of additional material, but list of further reading is not the same thing as proper references. Further reading could list works about the topic that were not ever consulted by the page authors. If some of the works listed in the that section were used to add or check material in the article, please list them in a references section instead. The Fact and Reference Check Project has more information. Thank you, and please leave me a message when a few references have been added to the article. - Taxman 19:18, Apr 22, 2005 (UTC)
* I am embarking to add some references to this article in coming weeks.  So expect to see a bunch of edits from me.  After adding a first reference to an arXiv paper I noticed that I used a different citation style for arXiv than has been previously done in the Further reading section.  Is that style the accepted standard for arXiv references on Wikipedia? --Bjohnson00 16:17, 10 May 2006 (UTC)
thread_title:  Request for references 

message: I think that QC is a boondoggle.  I say this with a heavy heart, as I was quite entranced by it as a postdoctoral researcher in Hans Mooij's group at Delft, working on single electronics circuits.
The theory is beautiful and elegant, and the possibilities are incredible-- and I mean "incredible" as in "not credible".  In order to implement the kind of operations such as in Shor's algorithm, you have to rotate the "qubit vector" by, for example, turning a signal on and off, such as the gate voltage employed by Nakamura et al..  The problem is that you need to be able to rotate the vector by 2 Pi/2^N, which translates to duty cycle times far below a nanosecond for solid-state systems (which are scalable) even at liquid helium temperatures.
:No you don't need to rotate to accuracy 2Pi/2^N.  Errors in quantum gates ADD, therefore to achieve constant accuracy for a polynomial sized algorithm you need accuracy which is basically one over the size of the algorithm.  For Shor's algorithm, for example, to factor a number of size N, you need an accuracy of order 1/log^c(N), where c is around 2.  Further, you never need in quantum computation to have a duty cycle (clock) which scales like this: you need only a universal set of quantum gates: "higher phase gates" are then made out of the these gates.  To understand why accuracies don't build up in such constructions, you then need to understand why fault-tolerant quantum error correction works.  
I would love to be proven wrong, but after being in the trenches for a while and an observer since then, I've lost faith in QC.  Keeping 10^3 - 10^4 qubits coherent in any sort of man-made environment seems irreproducible at best.
:Austin Fowler showed that Shor's algorithm still works if you skip rotations smaller than \pi/64, see  or . -- Tim Starling 06:53, 4 April 2006 (UTC)
replies: text: Yes, except that the payoff for society is vastly lower. Nuclear fusion would provide a clean, cheap, renewable energy source. Quantum computation would provide the ability for particularly wealthy governments to snoop on the communications of citizens. Most of the money comes from defence, so other applications haven't been seriously developed. Some have suggested that quantum computation would provide gains for computational chemistry and related fields, but such applications are certainly far more complicated than factorisation. -- Tim Starling 11:24, 12 April 2006 (UTC)
replies: text: Actually I think that gains in computational chemsitry are actually a lot less compicated than factorization.  For example recent work in Martin Head-Gordan has shown that quantum computers with around fifty qubits will beat todays classical algorithms (as opposed to in the thousands for breaking todays codes.) Dave Bacon 20:55, 28 April 2006 (UTC)
replies: text: This isn't a forum, people.  This has nothing to do with the article.  Whether it is a "boondoggle" or not, it exists in some form and has an article.  Please keep this discussion on how the article should be edited and keep opinions out.  —Preceding unsigned comment added by 128.227.98.88 (talk) 16:37, 16 October 2007 (UTC)
thread_title:  Boondoggle 

message: This article seems to have an unfair bias towards the NMR implementation (simply in the amount it covers and refers to it, and even the first picture at the top), while there is yet no separate page on NMR quantum computing. Would it be possible to move the NMR info into its own article without detracing from the content of this? I appreciate it would be harder to explain some of the concepts without a particular implementation in mind...
And yes, it's obviously an interdisciplinary field, so it's impossible to separate everything out nicely. Tomatoman 20:12, 6 January 2006 (UTC)
thread_title:  Bias towards NMR 

message: This is the entry:
"A quantum algorithm is an algorithm designed for use on a quantum computer." (and some links)
Ripper234 20:49, 2 April 2006 (UTC)
replies: text: Agree. Dictionary definition doesn't warrant its own page at this time. --Officiallyover 04:36, 3 April 2006 (UTC)
replies: text: Moved. Ripper234 15:44, 3 April 2006 (UTC)
thread_title:  Merge request from [[Quantum algorithm]] 

message: There is one other problem where quantum computers have a smaller, though significant (quadratic) advantage. It is quantum database search, and can be solved by Grover's algorithm. In this case the advantage is provable. This establishes beyond doubt that (ideal) quantum computers are superior to classical computers.
Doesn't this just establish that ideal quantum computers are superior to classical computers for dabase search, and not in general? Or am I missing something?—Matthew0028 17:56, 4 May 2006 (UTC)
replies: text: I think that this article is clear on what QC can do better than classical computers, but it never mentions on WHY it is better...what makes it better than classical computers? How is it that these algorithms can be run on QC and not classical? how about its ability to do parallel computations? or the significant gain in using resources like memory? Janechii 11:31, 8 May 2006 (UTC)
thread_title:  Superior to classical computers? 

message: How does Shor's algorithm work?  Our article on this subject currently contains the view of David Deutsch, which he happens to view as proof of the many worlds interpretation of quantum mechanics.  Are there are any other interpretations of how it physically works, by physicists (as opposed to internet amateurs?)  If so, these other POVs should be added to the Shor's algorithm article. RK 20:30, 11 June 2006 (UTC)
replies: text: Not _all_ of the worlds; just _most_ of them. If you look at things the David Deutsch way, the error rates are telling you the fraction of worlds that don't get the right answer. --76.216.10.112 (talk) 09:26, 1 March 2009 (UTC)
thread_title:  How does Shor's algorithm work? 

message: Even in the introduction, this article lacks a simple explanation for the novice.  I suggest a very simple explanation at the top, that anyone could understand, then progress deeper and deeper into the subject in subparagraphs.Landroo 14:48, 8 July 2006 (UTC)
replies: text: I am not all convinced that either issue can be further simplified. A QC exploits the unique features of quantum mechanics, so you cannot really understand what a QC is without understanding what QM is, and it is a difficult subject. What a present-day QC can do over a present-day  conventional computer is not a lot, but that is a misleading answer. The interest in QC lies in what it could do if developed sufficiently.1Z 15:09, 12 January 2007 (UTC)
thread_title:  Simplification required 

message: I don't quite understand why DNA-computers are lumped into the introduction as "classical" computers. At least to my knowledge, DNA computers are anything but classical (e.g., highly parallel and probabilistic and all that). If one really wants to mention DNA-computers, a far more elaborate explanation would be necessary; the way it is phrased now, it's misleading and highly imprecise. I suggest not to mention them at all.
DNA computers are classical in the sense that the word "classical" is being used here. "Classical" is used in opposition to the word "quantum" (common usage among physicists) and DNA computers are classical in this sense. Additionally, there are parallels between DNA computing and NMR spectrography based "ensemble quantum computing" (eg. see ). Sigfpe 22:59, 20 March 2007 (UTC)
thread_title:  DNA computing - better to omit it? 

message: :It is widely believed that if large-scale quantum computers can be built, they will be able to solve certain problems asymptotically faster than any classical computer.
I don't understand the usage of "asymptotically" in this sentence. Is the sentence claiming that the speed of classical computers can approach but never reach the speed of quantum computers at solving certain problems? If this is so, then the use of "asymptotically" is simply incorrect, because a curve can in fact possibly reach its asymptote and even cross it. I think that what is really meant is something like "incomparably".--Susurrus 04:43, 27 November 2006 (UTC)
thread_title:  "Asymptotically"? 

message: 'There is a common misconception that quantum computers can solve NP-complete problems in polynomial time.' I thought they could, can anyone explain this one? Paskari 20:09, 2 December 2006 (UTC)
replies: text: Generally, the assumption is that an NP-complete problem can't be solved by any means other than trying every possible combination; thus it will require fully-exponential time on a classical machine.
Now the problems which can be easily solved on quantum computers also have classical algorithms that run in less than fully-exponential time (ie they use time 2^sqrt(n) or the like), so they probably aren't NP-complete. So we expect that quantum computers also require fully-exponential (or at least more than polynomial) time on NP-complete problems. Grover's algorithm is probably the only one that provides any speedup for a complete problem, and it is only quadratic, so it turns time 4^n to time 2^n, which is not really useful. Ben Standeven 05:27, 29 January 2007 (UTC)

text: A quadratic improvement on 2^n is 2^[n/2], not 2^[squrt(n)] and is called "subexponential". 24.77.65.236 23:53, 25 February 2007 (UTC)
thread_title:  NP problems 

message: It is not an easy article, and I could see value in some "dumbed down" introduction to make it more accessible to people who are not well-versed in quantum mechanics or computer science.  
I am a lowly biologist/biochemist who dabbles in computer programming and materials, and I find this article to be very challenging.  But I like that.  This article gives me lots of food for thought and points me in lots of good directions.  I am very grateful to the editors of this article.   And I am impressed by the civility demonstrated here in the Talk section.
Cyclopiano 09:43, 9 December 2006 (UTC)
thread_title:  This article Rocks 

message: I am unable to update the article but if this newspaper is correct a small Canadian company has succeeded at making a Quantum Computer.
Link to article: 
Sir On The Edge 23:04, 13 February 2007 (UTC)
replies: text: D-wave has stated that currently the only thing their quantum computer has over classical computers is the word quantum in it's name. Anyone want to buy a quantum bridge? 24.77.65.236 23:57, 25 February 2007 (UTC)
thread_title:  Quantum Computers Now Exist, Update Article 

message: How about putting a short list here and point to other computers.
In the text there allready is a list.
What should be added to it is the neural computers.
Perhaps concepts could be added too like distributed computing
I dont mean the neural math, but the rat brains who can fly an airplane.
perhaps it's a sad thing they made rat brains do that.
But these days they create brain cell like other cell types.
And they can be attached to electronics.
Might be a good ide to also provide some information on what type of problems each computer type is good in.
Based on that then can be pointed out where a quantum computer fits in.
I think article could be made more complete by adding more type of problems a quantum computer can solve.
Or what kind of math direction is used here. —The preceding unsigned comment was added by 82.217.143.153 (talk) 23:07, 14 February 2007 (UTC)
thread_title:  List of types of computers incomplete ? 

message: Grover's algorithm is for an unstructured search. Shor's algorithm is for factoring an integer (rather order finding which is the heavy lifting in factoring). They answer different questions and cannot be compared. Shor's gives (logN)*3 running time. I assume by the quadratically better (logN)^1.5 you suggest that you wish to apply gover's on top of shor's, which cannot be done since grover's requires an Oracle. 125.14.79.216 16:44, 23 April 2007 (UTC)
replies: text: Wrong. For shor's algorithm need time n^2, while for grover algorithm 2^{n/2} time, where n is number of qubits.  —Preceding unsigned comment added by Weekwhom (talk • contribs) 05:22, 10 June 2008 (UTC)
thread_title:  What is diferent between Shor’s faktorization algoritm and Grover’s algoritm? 

message: This comment is in response to the request for help with the Featured Article review:
The section Power of quantum computers is fairly convoluted and is asking for a clean-up. The main problem seems to be the lack of focus (or structure): it wanders into certain problems with known efficient quantum algorithms, than wanders away, comes back... The "author" cannot decide whether to hail quantum computers for being able to break cryptoalgorithms or reassuring the reader that not all is lost. I think that the best way to deal with it would be to adopt the traditional order of exposition:
1. Explain Feynmann's idea (quantum simulation on classical computers).
2. Give an informal explanation of Deutsch's problem and Grover algorithm.
3. Give a very brief but clean explanation of the difficulty of integer factorization and discrete logs for classical computers; then explain Shor's breakthrough. Avoid vague statements, like the one about 300 digit numbers unless they can be backed up in the text (seems unreasonable).
4. Summarize the current (with the disclaimer) gap between the power of classical and quantum computation. The implications for cybersecurity can be mentioned there, but without repetitions and too many qualifiers. Complexity-theoretic statements need to be cleaner. If there are a disagreements about inclusions between various complexity classes, this article is not the place to settle them.
5. Defer all discussion of 'why this works?' type to the corresponding articles or a separate section. 
I hope this helps! Arcfrk 08:17, 10 April 2007 (UTC)
replies: text: I agree with a lot of the above.  This line is particularly a problem: "It seems plausible that it will always be possible to build classical computers that have more bits than the number of qubits in the largest quantum computer."  How so?  I understand the premise of the statement, but why can't quantum computers advance exponentially in relation to traditional machines? They certain could.  There's no reference or explanation.  That statement is an example of why that section is so convoluted.128.227.98.88 16:45, 16 October 2007 (UTC)
thread_title:  Power of quantum computers 

message: Please move anything back into the article you feel should not have been removed or place your comments on this action here. Skippydo 10:26, 27 July 2007 (UTC)
thread_title:  Moved Futher Reading to [[Talk:Quantum_computer/Further_Reading]] 

message: Ref 9 in the section "Quantum decoherence" is misplaced. Ref 9 does not discuss the increase of the number of qubits needed for fault tolerance. Rather, it questions the very possibility of fault tolerant quantum computation and presents a challenge for numerical verification 
of the proposed procedure for storing in memory just one qubit in the presence of realistic noise. (Karamzine 10:24, 10 August 2007 (UTC)
replies: text: Section 6 on page 4 of the article you refer makes reference to the Shor code and Steane code. Specifically it mentions that 7 physical qubits are required for each theoretical qubit. It might be better to reference the Shor and/or Steane papers directly. Skippydo 13:50, 10 August 2007 (UTC)
thread_title:  Reference misplaced 

message: it is not true that quantum computers just solve probabilistically...they are actually deterministic.  —Preceding unsigned comment added by 83.132.216.92 (talk) 00:24, 6 November 2007 (UTC)
thread_title:  Probabilistic? 

message: any pictures of a real quantum computer?--200.73.179.203 03:29, 15 September 2007 (UTC)
thread_title:  pictures 

message: Zegapain  should be mentioned in the QCs in fiction section --David13579 23:32, 6 November 2007 (UTC)
thread_title:  QCs in fiction 

message: I know this is probably asking the impossible, but can the general gist of this article be made accessible to someone without university level physics? Analogies might help. The example that comes to mind of such an analogy is that of heavy ball bearings sitting on a horizontal suspended rubber sheet to illustrate the curvature of space.
A walk-through example in very simple language might be good as well, for instance: What goes into a particular quantum logic gate, what happens there and what comes out of it?
As it is, I still haven't got the slightest clue why a set of 8 qubits should hold so much more information than 8 normal bits.
I hope this request doesn't seem thoughtless or rude. I am well aware of how difficult it is to make quantum physics intelligible to anyone, let alone non-physicists. Ireneshusband (talk) 22:07, 23 January 2008 (UTC)
replies: text: Well, I don't know that it's impossible to explain things in simpler language, but it's a challenge.  It's especially difficult because there's a pretty technical debate going on between editors of the page.  Didn't Einstein say something along the lines of "if you can't explain it to a child, you don't understand it"?  Perhaps all physicists have failed Einstein's test on the matter of quantum mechanics.  But we can always try to do better.  Gnixon (talk) 16:50, 4 June 2008 (UTC)
thread_title:  Can any of this be explained in layperson's terms? 

message: In most Wikipedia articles about potential/bleeding edge technologies, there are criticism sections about the revolutionary claims.  Does this page need to list criticisms of the idea of quantum computing?  Are there any valid criticisms of quantum computing or quantum computing theory or w/e? Nave.notnilc (talk) 01:44, 19 January 2009 (UTC)
thread_title:  Criticisms? 

message: January 22, 2009
SCIAM - Quantum Leap: Information Teleported between Ions at a Distance
Link between spatially separated ions could form the basis of quantum communications
By John Matson 
[snip]
:A group of researchers, however, report today in Science that they've made headway in quantum teleportation, and thus communication. The team, led by physics graduate student Steven Olmschenk at the University of Maryland, College Park, succeeded in teleporting quantum information between ytterbium ions (charged atoms) three feet (one meter) apart.
[/snip]
http://www.sciam.com/article.cfm?id=quantum-teleportation-with-ions
jwalling (talk) 23:40, 22 January 2009 (UTC)
thread_title:  SCIAM - Quantum Leap: Information Teleported between Ions at a Distance 

message: Could someone please decide what is the appropriate treatment for quantum parallelism. — RHaworth (Talk | contribs) 05:54, 9 February 2009 (UTC)
replies: text: Are you asking, should quantum parallelism link to quantum computer? Skippydo (talk) 18:06, 9 February 2009 (UTC)

text: The redirect QC should remain. The previous content was nonsense. Quantum parallelism likely does not deserve it's own article. Skippydo (talk) 19:06, 10 February 2009 (UTC)
thread_title:  fork 

message: * Quantum register: A scalable physical system with well characterized [???] representing qubits that in turn compose the quantum register.
* Initialization: The ability to prepare the state of the register in a initial state.
* Universal set of gates: The ability to implement a universal set of logic gates.
* Low error and decoherence rate: High fidelity of gate operation, with probability per gate [???] < 10−3 and qubit decoherence times that are longer than the gate operation time.
* Read-out: The ability to reliably measure the state of individual qubits [???] the computational basis.
The [???] represent what appear to be missing words:
* Well characterized whats representing qubits?
* Probability per gate of what < 10-3?
* For the third one, I'm not entirely sure what's missing, but it's not a sensible phrase as it stands.
Because I don't know what's supposed to be here, and there's no citation I can follow to see the source that's being summarized, I can't fix it. Hopefully the original author or someone else can. --76.216.10.112 (talk) 09:06, 1 March 2009 (UTC)
replies: text: I've simply removed the offending content. Skippydo (talk) 19:21, 1 March 2009 (UTC)
thread_title:  Incomplete phrases in "Potential" section 

message: Can someone more familiar with the subject please review the section Genome evolution analogous to quantum computer. I have tagged it as Original research since no citations are given and the embedded links do not show any of this behaviour described in the section. HumphreyW (talk) 03:44, 9 April 2009 (UTC)
replies: text: Thanks for explaining some more. Is the use of the terms 'cohere' and 'de-cohere' the same meaning as used when discussing QC coherence/decoherence? I can't see how this relates to QCs for the purpose of computing. HumphreyW (talk) 14:15, 9 April 2009 (UTC)

text: Okay, but none of that says anything about it being related to 'Quantum' Coherence. Explaining about genes and alleles is all very well but you still have not shown how any of it relates to QC. The word cohere has more meanings than one and I think you are confusing the word 'cohere' above to mean that it is somehow involved with Quantum coherence. Please explain how all the above is related to QC. Thanks. HumphreyW (talk) 23:06, 9 April 2009 (UTC)
replies: text: This section does not belong in this article. "Decoherence" is being used in a completely different sense. This is not quantum information processing (although, it is, of course, computation). Perhaps this could be added to DNA computer? Or Computational gene or Biocomputer? ---- CharlesGillingham (talk) 01:15, 10 April 2009 (UTC)
replies: text: Until the relevance of the section can be properly determined I have placed the section within HTML comment tags. HumphreyW (talk) 07:07, 10 April 2009 (UTC)
thread_title:  Genome evolution analogous to quantum computer 

message: Wikipedia is not a science journal. It is a public use online encyclopedia and therefore all scientific terminology or explication should include explanations that are clearly understandible to the average non-scientist reader. Sean7phil (talk) 19:05, 19 May 2009 (UTC)
thread_title:  Article May Be Too Advanced for the Lay Reader, Consider using examples, and metaphor 

message: Can someone (with more knowledge in these matters) include information about this breaking news? Here are various links to the same article:
*
*
*
: This morning I was reflecting on the possibilities of a computer that can tell us that '2 + 2 = 4' with greater than 50% probability. ;-) —RJH (talk) 21:57, 16 November 2009 (UTC)
thread_title:  First electronic quantum processor! 

message: Shouldn't article have a generic "problems and limitations" section? Gravity-induced decoherence for example can be a fundamental limitation. Fundamental "quantum limit on computing speed is another one. --Dc987 (talk) 22:02, 14 December 2009 (UTC)
thread_title:  Problems and Limitations 

message: Perhaps the Ternary quantum computer can be mentioned ? See http://nextbigfuture.com/2009/08/qudits-multilevel-versions-of-qubits.html  —Preceding unsigned comment added by 81.243.191.103 (talk) 12:38, 6 January 2010 (UTC)
thread_title:  Tertiary quantum computer 

message: Does anyone object to me setting up automatic archiving for this page using MiszaBot? Unless otherwise agreed, I would set it to archive threads that have been inactive for 30 days and keep at least ten threads.--Oneiros (talk) 21:06, 23 January 2010 (UTC)
replies: text: Sounds good. --Robin (talk) 22:18, 28 January 2010 (UTC)
replies: text: --Oneiros (talk) 11:34, 18 February 2010 (UTC)
thread_title:  Automate archiving? 

message: Are there any production ready quantum computers and what are they being used for ?
Amazon claim the http://aws.typepad.com/aws/2010/04/introducing-qc2-the-quantum-compute-cloud.html is actually a quantum computer any one with info ? Kendirangu (talk) 06:12, 12 April 2010 (UTC)
thread_title:  Production-ready quantum computers 

message: can anybody in earth-human terms explain this matter...
:yeah I agree. this article has plenty of good information in it but is poorly organized and explained. I understand that more advanced articles such as the one on topological quantum computation cannot accurately be brought to the level of the layperson, but this article needs a lot of work.  — Preceding unsigned comment added by 208.92.16.72 (talk) 16:32, 9 June 2011 (UTC)
thread_title:  what ***** does this mean 

message: It was mentioned in [this article] by Hot Hardware. I believe this could be expanded in respect to this Quantum computer article. Komitsuki (talk) 14:03, 22 September 2010 (UTC)
thread_title:  Centre for Quantum Photonics? 

message: The reason someone looks up "quantum computer" in an encyclopedia is not because they are already quantum physicists. I couldn't even find a reasonably phrased statement on how much faster quantum computers would be than deterministic computers of comparable size. This article reads like it was written either by people who want to show off, or people who are so oblivious that they are completely incapable of translating technical language into plain language. The level of technical language in this article is inappropriate for an encyclopedia. Could someone who has: (a) knowledge of quantum computers, AND (b) an ability to speak and interact socially with normal human beings, and (c) no desire to prove to the world how intelligent they are, please rewrite this article successfully? Thanks. --Daniel (talk) 22:45, 10 August 2011 (UTC)
thread_title:  Article Failure 

message: i just wanted to know what "2n/2 invocations of the underlying cryptographic algorithm" means. I think there should be a link or explanation, not just a casual use of this phrase then on to the next thing. skank-L juice 00:55, 28 September 2010 (UTC)
replies: text: What is confusing, the use of 2n/2, the phrase "invocations of the underlying cryptographic algorithm", or the whole thing? —UncleDouggie (talk) 05:34, 28 September 2010 (UTC)
replies: text: omg... look, if a supposed date dont get it, its too complex for an introductionary article. If in doubt, go have a date and say "2n/2 invocations of the underlying cryptographic algorithm" and check her facial expresion. You can also try it with granny.  —Preceding unsigned comment added by 85.226.3.146 (talk) 20:13, 11 November 2010 (UTC)

text: Yo mom, you know about "2n/2 invocations of the underlying cryptographic algorithm"? You didnt? o.0  —Preceding unsigned comment added by 85.226.3.146 (talk) 20:39, 11 November 2010 (UTC)

text: well, I'll only be satisfied if I try this line on Jimbo Wales. then I'll know if it's good pedia content or.. well, I'll know what kind of lay-person intelligibility I'm looking at. 96.245.96.95 (talk) 14:47, 4 July 2011 (UTC)
thread_title:  what?({{what}}) 

message: I cannot see any compelling reason to have the second paragraph in the section "Potential". It blows up the article and is off-topic in this section. It also sounds like an advertisement to post-quantum cryptography and should be the content of the individual article about PQC. The first paragraph already states that quantum computers allow to "decrypt many of the cryptographic systems in use today",...  —Preceding unsigned comment added by 130.83.224.120 (talk) 11:56, 18 October 2010 (UTC)
thread_title:  Advertisement to post-quantum cryptography 

message: This article uses the phrase "universal gate set".
What does that mean?
And how is this related to the "universal quantum computation" mentioned in the Toffoli gate article?
Does that phrase mean something like "any set of gates that, given sufficient numbers of them, can be cascaded to form a Turing-complete machine."? Or is there something more to it than that?
Is there some other article that describes  "computational universality" and "universal gate set" (and the distinction, if any, between them) in more detail?
And perhaps lists a few examples?
--68.0.124.33 (talk) 04:54, 8 February 2011 (UTC)
replies: text: If I recall correctly, it denotes a set such that an arbitrary gate can be approximated by a sequence of gates from that set. Since there is no memory/state, I don't think it is directly related to Turing-completeness. Skippydo (talk) 03:43, 10 February 2011 (UTC)
thread_title:  universal gate set 

message: The article was recently changed to say "Ignoring computational and space constraints, it is not known if a quantum computer is capable of solving problems which classical computers cannot." Of course, this is wrong as a quantum computer can be simulated on a classical machine given enough time and space. Recommend we revert back to what it previously said: " If one disregards the question of efficiency (i.e., given enough time and resources) all problems solvable with a quantum computer can also be solved using a traditional computer."  —Preceding unsigned comment added by 75.15.129.234 (talk) 20:46, 1 April 2011 (UTC)
replies: text: You are correct. In accidentally negated one of the statements in an earlier copyedit. I looked up the reference just to be sure, and indeed, what you say is true. Skippydo (talk) 19:31, 2 April 2011 (UTC)
thread_title:  Can't Solve the Halting Problem! 

message: Citation number 4 is unclear. I know nothing about this and can't follow the citations. Someone who knows something help?Darrell Wheeler (talk) 14:23, 9 April 2011 (UTC)
replies: text: The book is very well-known in the field. I've given a more helpful citation. Perhaps you'll find this helpful. Skippydo (talk) 19:37, 11 April 2011 (UTC)
thread_title:  Bad Citation 

message: It would seem that an article on quantum /computers/ would give some details on the  sort of hardware that is either available, or which theoretically needs to be available, in order to construct a functional "quantum computer."  Yet I don't seem to be finding any information like this in the article.  Can quantum computers be built on electronic circuitboards using doped silicon chips?  Do they require linear particle accelerators or massive installations like the Large Hadron Collider?  Can they be made with Tinker Toys(tm) and Legos(tm).  Or what?
In fact, this article is about theories of quantum /computing/, and not about quantum /computers/, per se.  I suggest changing the title accordingly, or else furnishing the requisite hardware information.  —Preceding unsigned comment added by 74.92.174.105 (talk) 00:20, 4 May 2011 (UTC)
thread_title:  "Computer" versus "Computing" 

message: The basic idea behind this (?) is that regular bits are either OFF (A) or ON (B).  And according to my layperson understanding, this qubit has three states (A), (B), and (AB) sort of like blood types.  But this article is impossible for a layperson to get basic information like that readily.  And I think somewhere is a connection to basic particles of protons (+1), neutrons (0), and electrons (-1).... because those also have 3 states.  — Preceding unsigned comment added by 67.244.121.144 (talk) 15:22, 17 June 2011 (UTC)
thread_title:  Horrendous & Impossible to read 

message: I know somewhere I read about retrocausal quantum computer theories; where computations would be completed before they were initiated. Why isn't there any linkage to literature on that? 74.209.54.156 (talk) 10:04, 21 July 2011 (UTC)
thread_title:  [[Retrocausality]] in quantum computing 

message: "One of the more bizarre properties of QCs was identified by a team at the University of Illinois at Urbana-Champaign. They presented the first demonstration of "counterfactual computation", inferring information about an answer, even though the computer itself did not run"  66.243.213.232 (talk) 01:02, 17 September 2011 (UTC)
thread_title:  Article on [[counterfactual computation]]? 

message: comparing the text beginning at the first chapter of Quantum Computing by Ximena Byrnes, a 2011 online book with , the text on wikipedia is an almost exact copy. but there is no mention of the book in the sources.
link to book, probably wont work:
http://reader.eblib.com.ezproxy.library.wisc.edu/%28S%28ir3chenla3d1fdhoirwzpvxv%29%29/Reader.aspx?p=735741&o=691&u=UW555H383&t=1317245875&h=703F320C432AF3360021BC30CA61E25A417B03D7&s=10849733&ut=2121&pg=1&r=img&c=-1&pat=n#  — Preceding unsigned comment added by 128.104.0.87 (talk) 21:47, 28 September 2011 (UTC)
replies: text: The introduction to this article predates the publishing of the book by a wide margin. The appropriate question is does the book cite wikipedia. Feel free to paste the offending portion of the book here and we can have a laugh about it. Skippydo (talk) 22:12, 28 September 2011 (UTC)
replies: text: Yeah, the book should cite wikipedia, not the other way around. But I don't see any citations.
Here is the first five pages of the ebook. Except from the images taken from wikipedia, the book is a plain text document with bolded and enlarged text headings. Looks like something made quickly in microsoft word. And I don't see any citations anywhere. 
<<page 1 of 101>>
[the cover of the book, blue with a double helix on top of a keyboard.]
<<page 2 of 101>>
First Edition, 2011
© All rights reserved.
Published by:
The English Press
4735/22 Prakashdeep Bldg,
Ansari Road, Darya Ganj,
Delhi - 110002
Email: info@wtbooks.com
<<this part is sideways on the left margin of every page, so i'll delete it after this>>
© Byrnes, Ximena, May 01, 2011, Quantum Computing
The English Press, New Delhi, ISBN: 9789381157916
<<page 3 of 101>>
Table of Contents
Chapter 1- Introduction to Quantum Computing
Chapter 2 - Quantum Superposition
Chapter 3 - Quantum Entanglement
Chapter 4 - Superconductivity
Chapter 5 - Quantum Dot
Chapter 6 - Nitrogen-Vacancy Center
Chapter 7 - Bose–Einstein Condensate
Chapter 8 - Important Concepts in Development of Quantum Computing
Chapter 9 - Qubit
Chapter 10 - Timeline of Quantum Computing
<<page 4 of 101>>
Chapter- 1
Introduction to Quantum Computing
<<image of bloch spere from wikipedia>>
The Bloch sphere is a representation of a qubit, the fundamental building block of
quantum computers.
A Quantum computing is also called quantum computer is a device for computation
that makes direct use of quantum mechanical phenomena, such as superposition and
entanglement, to perform operations on data. Quantum computers are different from
traditional computers based on transistors. The basic principle behind quantum
computation is that quantum properties can be used to represent data and perform
operations on these data. A theoretical model is the quantum Turing machine, also
known as the universal quantum computer.
Although quantum computing is still in its infancy, experiments have been carried out
in which quantum computational operations were executed on a very small number of
qubits (quantum bit). Both practical and theoretical research continues, and many
national government and military funding agencies support quantum computing
research to develop quantum computers for both civilian and national security
purposes, such as cryptanalysis.
If large-scale quantum computers can be built, they will be able to solve certain
problems much faster than any current classical computers (for example Shor's
algorithm). Quantum computers do not allow the computation of functions that are
not theoretically computable by classical computers, i.e. they do not alter the Church–
Turing thesis. The gain is only in efficiency.
Basis (bold heading at bottom of page)
-----------------------------------------------------------------------------------------------------------
<<page 5 of 101>>	
A classical computer has a memory made up of bits, where each bit represents either a
one or a zero. A quantum computer maintains a sequence of qubits. A single qubit can
represent a one, a zero, or, crucially, any quantum superposition of these; moreover, a
pair of qubits can be in any quantum superposition of 4 states, and three qubits in any
superposition of 8. In general a quantum computer with n qubits can be in an arbitrary
superposition of up to 2n different states simultaneously (this compares to a normal
computer that can only be in one of these 2n states at any one time). A quantum
computer operates by manipulating those qubits with a fixed sequence of quantum
logic gates. The sequence of gates to be applied is called a quantum algorithm.
An example of an implementation of qubits for a quantum computer could start with
the use of particles with two spin states: "down" and "up" (typically written and
, or and ). <<<<<the same symbols as wikipedia uses, but it didn't transfer here>>>> But in fact any system possessing an observable quantity A which
is conserved under time evolution and such that A has at least two discrete and
sufficiently spaced consecutive eigenvalues, is a suitable candidate for implementing
a qubit. This is true because any such system can be mapped onto an effective spin-
1/2 system.
<<same picture that wikipedia has about qubits>>
Bits vs. qubits
Qubits are made up of controlled particles and the means of control (e.g. devices that
trap particles and switch them from one state to another).
Consider first a classical computer that operates on a three-bit register. The state of
the computer at any time is a probability distribution over the 23 = 8 different three-bit
strings 000, 001, 010, 011, 100, 101, 110, 111. If it is a deterministic
computer, then it is in exactly one of these states with probability 1. However, if it is a
probabilistic computer, then there is a possibility of it being in any one of a number of
different states. We can describe this probabilistic state by eight nonnegative numbers
a,b,c,d,e,f,g,h (where a = probability computer is in state 000, b = probability
computer is in state 001, etc.). There is a restriction that these probabilities sum to 1.
-----------------------------------------------------
so its a very similar copy, with the images copied exactly. The first chapter is mainly a copy and paste of this article. Comparing the wikipedia articles that correspond to the titles of the other chapter looks to give the same result: copying. not everything was copied exactly, but the majority was that i noticed while quickly looking through it. Perhaps somebody copied wikipedia articles into microsoft word, put them together, and used an online image for the cover (the cover image is the first result when searching for "dna keyboard" on google. And its available in many sizes according to google. Interesting. 146.151.54.140 (talk) 00:32, 5 October 2011 (UTC)

text: Here's Wikipedia's policy on the issue: . I suspect copyright laws in India aren't so strong and thus pursuing the issue would be a waste of time. Any comments? Skippydo (talk) 19:20, 5 October 2011 (UTC)
thread_title:  this is copied from a book 

message: Is there any good information on what an "analog" (non-qubit?) quantum computer, or "quantum real computer" would entail being, exactly? Could there be mention of such in this article if it is meaningful. I assume it may entail quantum waves rather than quantum 'digital' particles? 216.227.117.152 (talk) 08:04, 29 September 2011 (UTC)
replies: text: A quantum computer is analog (and probabilistic) by definition. Skippydo (talk) 19:59, 29 September 2011 (UTC)
replies: text: Is not the definition of the use of bits, whether qubits or not, digital by definition? 216.227.117.152 (talk) 00:03, 30 September 2011 (UTC)
replies: text: Digital means two states. A bit, by definition, has only two states. A qubit has an infinite number of states. Skippydo (talk) 17:19, 30 September 2011 (UTC)
replies: text: Binary means two objective states, but doesn't digital mean relational duality, literally: "representing data as a series of numerical values" even an infinite series? Qubits ultimately normalize objectively into being only one state in relation to one other state as output? I think of the difference as particle (localized: qubit) or wave (nonlocal: analog) 216.227.117.152 (talk) 23:13, 30 September 2011 (UTC)
thread_title:  [http://physics.stackexchange.com/questions/8169/is-analog-quantum-computation-not-useful is "analog" quantum computation not useful?] 

message: In this wikipedia article it is claimed that the quantum turing machine does not violate the Church-Turing thesis. However, in this survey: http://www.cs.berkeley.edu/~vazirani/bv.ps the authors claim to give the first formal evidence that the (modern) Church-Turing thesis is violated by the quantum turing machine. In my opinion, this should be investigated and straightened out. Cbswe (talk) 14:21, 17 December 2011 (UTC)
replies: text: Quantum computers don't violate the Church-Turing thesis, though they might violate a stronger version of thesis, which is sometimes called the extended or physical CTT. --Robin (talk) 05:45, 21 December 2011 (UTC)
thread_title:  Church-Turing thesis violated or not? 

message: In the 'Bits vs. qubits' section the letter set (a,b,c,d,e,f,g,h) is first used as a set of probabilities and in the next sentence as a set of vector coefficients.
"We can describe this probabilistic state by eight nonnegative numbers a,b,c,d,e,f,g,h (where a = probability computer is in state 000, b = probability computer is in state 001, etc.). There is a restriction that these probabilities sum to 1.
The state of a three-qubit quantum computer is similarly described by an eight-dimensional vector (a,b,c,d,e,f,g,h), called a ket. However, instead of adding to one, the sum of the squares of the coefficient magnitudes, |a|^2+|b|^2+...+|h|^2, must equal one."
As pointed out in the text, in the latter case the probabilities are equal to the squares of the coefficients a,b,c..., which is confusing.  A different letter sets should be chosen for the probabilities and the vector coefficients, e.g. capital letters (A,B,C,D,E,F,G,H), where A=|a|^2 for the probabilities.  — Preceding unsigned comment added by Zinger0 (talk • contribs) 20:07, 27 December 2011 (UTC)
thread_title:  (a,b,c,d,e,f,g,h) - Probabilities and vector coordinates 

message: In the English Quantum computer article it says close to the end:
'It has been speculated that theories of quantum gravity, such as M-theory or loop quantum gravity, may allow even faster computers to be built.'
We want to know where one can find more information regarding this topic.
Perhaps the author can share what he/she thinks of computers that may differ from the quantum computer building principle we see today?
Vachapaha (talk) 09:10, 19 May 2012 (UTC)
thread_title:  Clarification of a speculation on the subject related to quantum computers. 

message: Why are there not citations to the prior arts of Quantum Isolation based Classical Scale Quantum Computers?  It seems there should be some references to this approach, given the description of Schrodinger's Cat Systems, where a radioactive source with an indefinite quantum decay time, is used to make one probabilistic branch on the outcome of a cat placed in that quantum system, that is projected into one state again, when a larger system Quantum Grounds the system.  For Quantum Isolation based Classical Scale Quantum Computers, a Classical Scale Computer is placed into Quantum Isolation, like a Spaced Based Orbiting Computer Satellite, and Radioactive Source decays all of indefinite quantum time are used to produce computer branching data, that places a classical scale computer system into an Operational Superposition of States, taking every potential branch from the greater universe system perspective, and after executing its code, the satellite broadcasts its branch record, with a delay proportional to the criteria of result utility, causing Quantum Grounding of the Computer's Superposition.  Conversely, without such references, makes the implication that the concept of Schrodinger's Cat Systems is often over applied, with a lack of empirical pragmatic results in any real world application, like Quantum Isolation based Classical Scale Computers, where radioactive sources can place the Classical Scale Computer into two or infinite number of Superposition States, reducible to the optimal solution, like the ubiquitous Schrodinger's Cat Concept.  Ref. SET236765732714909171744543750.  76.167.47.5 (talk) 17:01, 22 June 2012 (UTC)
thread_title:  Quantum Isolation Quantum Computer References 

message: The image :File:Quantum_computer.svg provides an incomplete, misleading mental model for a collection of qubits. In particular, it has no way of representing quantum entanglement (e.g. there is no way to represent the state |0> + |4> using this pictorial representation). Garrison (talk) 18:17, 4 September 2012 (UTC)
thread_title:  Bits vs. qubits image is misleading 

message: I am surprised by the absolutely incorrect and misleading use of Ref. 19: "For a 1000-bit number, this implies a need for about 104 qubits without error correction.[19]" First, it is not true, the correct estimate can be found in many books published previously to Ref. 19. Second, there is no such statement in Ref. 19. And third, and most important - as can be seen from the title "Is fault-tolerant quantum computation really possible?" - Ref. 19 contains a critical discussion of the existing principles of quantum error correction and the foundations of the threshold theorem. To my knowledge, the presented arguments were never refuted, but rather simply ignored. It would be only fair to present a critical point of view in this article (instead of advertising D-wave achievements, which are quite doubtful)  — Preceding unsigned comment added by Karamzine (talk • contribs) 17:38, 6 September 2012 (UTC)
thread_title:  Wrong use of Ref. 19. No discussion of critical opinions on possibility of QC 

message: Not sure whether this: http://www.gatech.edu/newsroom/release.html?nid=125111 has allready been mentioned in the developments section
91.182.142.202 (talk) 11:39, 1 October 2012 (UTC)
thread_title:  April 2012 breaktrough 

message: The statement "Whereas digital computers require data to be encoded into binary digits" is not true. 82.38.204.141 (talk) 17:31, 9 October 2012 (UTC)
thread_title:  "Require" applied to binary 

message: I think so, if it get smaller and smaller the transistor, it will be quantum computer.180.194.251.97 (talk) 00:10, 3 January 2013 (UTC)
thread_title:  The future of the computer is quantum computer? 

message: bullshit.  — Preceding unsigned comment added by 109.60.126.42 (talk) 00:30, 3 January 2014 (UTC)
thread_title:  This article is like 

message: the phrase "and thus far quantum computers have yet to solve a problem faster than a classical computer." is wrong.
http://www.gizmag.com/d-wave-quantum-computer-supercomputer-ranking/27476/
talking about D-Wave, a 512 bit quantum computer (just over 400 functional bits)
" On the largest problem sizes tested, the V5 chip found optimal solutions in less than half a second, while the best classical software solver required 30 minutes to find those same solutions. This makes the D-Wave computer over 3,600 times faster than the classical computer in these tests."  — Preceding unsigned comment added by 115.64.210.168 (talk) 12:41, 14 May 2013 (UTC)
thread_title:  Quantum computers are not slower in all cases 

message: A Bloch CPU or "Bloch entangled transistor sphere [BETS]" is not an actual quantum computer, but it can be used as a "control unit" of an actual computer, it is zillion times slower than an analogue qubit, also the BETS does not allow all answers, thus you have to run it more times to average
a result closer to the actual value.
It either is an actual transistor sphere [having transistors on it's surface], but more commonly two entangled circles represent all posible
connections of the Bloch sphere. Many entangled BETS (consisting of a multiple of two as entangled set-members number) consist the Bloch CPU.
It can be used in a non professional way for example as a music, visual effects or video games secondary CPU, when we want a fast intricate and realistic result, but we do not have to run all the suggested times to get the actual average of the wavefunction collapse (non optimum averaging settings NOAS). It works in classic CPU temperatures, it's production is cheap (the classic CPU production techniques are required), it is mass production friendly. A BETS set of 32 entangled spheres when used at NOAS[not fully averaged to save time] mode, can mimic for example realistically
many guitar amps and pedals. A classic CPU always is required to control the BETS averaging. For professional or academic use, when we demand
a thorough averaging, it can only be used as a secondary control, test or filter of an actual quantum computer, because BETS are slow and not built to replace an actual quantum computer.  Noise generators with controllers can provide faster inputs than a program controlled by a classic CPU, thus a noise generator unit NGU is required to avoid CPU overload — Preceding unsigned comment added by 2.84.219.136 (talk) 21:59, 19 May 2015 (UTC)
thread_title:  Bloch CPU 

message: A probabilistic CPU, is not an actual quantum computer, but a "Markov chain" CPU.
Theoretically a P-CPU can perform identically with a Q-CPU but incredibly slower (zillion times slower).
The future of quantum computing will include on the same motherboard both a P-CPU and a Q-CPU.
The P-CPU will set the probabilistic tasks and a Q-CPU will perform the main calculation, then a classical CPU will distribute the data
viscerally (towards motherboard components) and peripherally (towards peripherals).
Elongated or complex tasks are better set by a P-CPU as a Q-CPU input and re-evaluative/parametrizational (IREP) component.
Thus a functional mass production quantum computer (Classical-Quantum-Probabilistic - CQP computer) will include 3 CPU genres.
The main article doesn't mention anything about CQP computing. — Preceding unsigned comment added by 2.84.219.136 (talk) 09:38, 14 May 2015 (UTC)
thread_title:  Probabilistic Computing - Probabilistic CPU - PCPU 

message: An experimental stage of up to 4 entangled particles has been tested. At the final stage it is supposed to be able to entangle up to some billion particles for a personal device, and some septillion or more for quantum servers. That will take at least 300 years from now according to nowadays awareness.
This article is not analytical enough about quantum CPUs built with Probabilistic Entanglement Channels (PECs), and it's a crucial mistake,
because all quantum computing companies punctuate PECs' importance. Silicon tubes instead of carbon-based, are more suitable for quantum computing (for biological purposes, multicarbons are prefered) — Preceding unsigned comment added by 2.84.213.154 (talk) 11:42, 12 May 2015 (UTC)
thread_title:  Quantum CPU with Carbon nanotubes (CNTs) Probabilistic Entanglement Channels (PECs) 

message: 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)
thread_title:  Quantum supercomputer 

message: :/( 
"..(-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)
replies: text: /(
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)

text: 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)
thread_title:  Announcing new results 

message: :/(
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)
replies: text: 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)
thread_title:  deleting of new idea announcing 

message: 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)
thread_title:  other wiki for discussing quantum ideas 

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

text: 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)
thread_title:  Contradictory statements regarding space? 

message: 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)
thread_title:  misc suggestions / solving chess - programming the universe - more intuitive intro 

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

message: 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)
replies: text: —Ruud 18:01, 21 December 2014 (UTC)
thread_title:  Page title should be "Quantum computing" 

message: 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)
replies: text: —Ruud 18:01, 21 December 2014 (UTC)
thread_title:  strongly need th consider of change the title of this wiki-page from Q. "Computer" to "COMPUTING"  

message: 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)
replies: text: 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)
thread_title:  Invented When? 

message: 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)
replies: text: 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)
thread_title:  Minthreadsleft 

message: 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)
thread_title:  Three-bit Example?