Talk:Toffoli gate

message: In normal logic, XOR is NOT reversible. It is not possible to tell which input did what given only the output. If this isn't what you meant, the ststement needs clarification Graham 03:57, 17 Mar 2004 (UTC)
thread_title: Untitled

message: Great article. It's refreshing to see an article on quantum computing without pedantic descriptions of orthogonality, Hamiltonians... I do have a problem with the intro. Generally, scientists don't "invent" abstract concepts, only the methods used to describe them. So Einstein described/discovered special relativity but Feynman invented Feynman diagrams (used to describe particle-antiparticle interactions). Anybody else agree that the wording needs to be changed? Zyxoas (talk to me - I'll listen) 20:03, 26 May 2006 (UTC)
thread_title:  Use of the word "invented" 

message: The introduction had linked the word universal to Universality (philosophy) which is clearly wrong - universal as used here is a mathematical/computer science term.  A closer link would be Turing completeness but I'm not sure whether the definition of universal here is quite the same as in that article (one seems to be about boolean functions, the other about natural numbers, for example).
At least for now I just unlinked "universal".  The relevant definition of "universal" is given further down in the article. Kingdon 21:04, 19 January 2007 (UTC)
thread_title:  Link to Universal 

message: The logic image is unclear. What do the dots, lines, and circle represent? Zylstra (talk) 20:24, 27 February 2018 (UTC)
thread_title:  Image 

message: I removed the text ", thus its quantum cost is five." following the sentence regarding how the Toffoli gate can be implemented with 5 two-bit gates.  First of all, there is no agreed on measurement for "quantum cost".  You would only care about the number 5 rather than say 17 if you were actually implementing things, and then you would be measuring cost in terms of your implementation, in which it may be the case that not all two-bit gates are created equal.
Additionally, it is not proven that the Toffoli cannot be implemented with fewer than 5 quantum gates.  —Preceding unsigned comment added by Phrenophobia (talk • contribs) 06:58, 30 July 2008 (UTC)
thread_title:  Quantum cost 

message: The information in Background is very helpful to understanding the confusing, multidisciplinary aspects of quantum computing. I recommend creating an entry for Reversible Gates and expanding on the information presented in the background. I am aware of the entry Reversible Computing, but I believe it lacks a tangible nature that was clarified here.
--*elAndres (talk) 18:28, 30 March 2011 (UTC)
thread_title:  Create Reversible Gate Entry 

message: At the end of the article, there is a sentence I can't understand : "However, the Toffoli gate can not be used for universal quantum computation, though it does mean that a quantum computer can implement all possible classical computations." Can someone explain or make it clear ? Thanks, Zandr4[Kupopo ?] 07:54, 16 January 2014 (UTC)
thread_title:  Weird sentence 

message: In the article there is : "the only non-trivial gate is the controlled NOT gate". What make it non-trivial is not clear (if I add to guess I would say it's would be the use of a logical function like XOR). It's not clear either if being non-trivial is an important property and why.  — Preceding unsigned comment added by Astyan42 (talk • contribs) 01:53, 3 February 2017 (UTC)
thread_title:  non-trivial gate 

message: The section mentions the relationship between Toffoli gates and thermodynamics, and the following source may provide the relevant information necessary for a citation: R. Landauer, "Irreversibility and heat generation in the computing process," IBM Journal of Research and Development, vol. 5, pp. 183-191, 1961. --Beaker Bytes (talk) 14:52, 16 January 2019 (UTC)
thread_title:  Citations needed for Background section 

message: The article references the Deutsch gate in the Related logic gates section. The Deutsch gate has an angle associated with it that when chosen to be pi/2 yields the Toffoli gate. I think this may be worth mentioning. Pbellys (talk) 02:01, 14 April 2020 (UTC)
thread_title:  Deutsch gate