Talk:Quantum Turing machine
 | This article is rated Start-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||||
Merger proposal
The aricles on Universal quantum computer and Quantum Turing machine describe the same concept. Universal quantum computer should redirect to Quantum Turing machine, just like Universal computer redirects to Turing machine. —Preceding unsigned comment added by RobinK (talk • contribs) 20:00, 5 July 2009 (UTC)
- Merged. --Robin (talk) 16:42, 9 July 2009 (UTC)
No definition?
I think the page on QTMs would be much more useful if it actually contained a definition of what a QTM is. Simphilip (talk) 04:47, 1 December 2010 (UTC)
- I added a very short and somewhat flawed hand-waving definition. Hope that helps. 67.198.37.16 (talk) 22:02, 15 August 2015 (UTC)
Computational equivalence
The lead states of QTMs, citing Yao ‘Quantum circuit complexity’:
- However, the computationally equivalent quantum circuit is a more common model.
However, Revisiting the simulation ofquantum Turing machines byquantum circuits states:
- Yao’s 1995 publication ‘Quantum circuit complexity’ proved that quantum Turing machines and quantum circuits are polynomially equivalent computational models: t≥n steps of a quantum Turing machine running on an input of length n can be simulated by a uniformly generated family of quantum circuits with size quadratic in t, and a polynomial-time uniformly generated family of quantum circuits can be simulated by a quantum Turing machine running in polynomial time.
Given that we care about characterising complexity classes, the looseness in this two-way tie seems to fall rather short of the claim of computational equivalence. Should this be amended? — Charles Stewart (talk) 15:04, 15 July 2021 (UTC)
- according to my understanding, the standard notion of equivalence in complexity theory (and certainly in quantum computing) is "up to polynomial overhead". We care mostly about problems in the class BQP, and under an encoding with at most poly overhead, that class does not change. Moreover, the overhead is needed both to simulate a quantum circuit on a QTM and to simulate a QTM on a circuit - so in general one cannot say which model is the "better" one. See eg. [1] for another work showing "polynomial equivalence" between two models of quantum computation. --Qcomp (talk) 21:12, 15 July 2021 (UTC)
Content Disclaimer
Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.
- The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
- There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
- It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
- Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
- Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.