Quantum Zero-Error Algorithms Cannot be Composed
Quantum Physics
2007-05-23 v2 Computational Complexity
Abstract
We exhibit two black-box problems, both of which have an efficient quantum algorithm with zero-error, yet whose composition does not have an efficient quantum algorithm with zero-error. This shows that quantum zero-error algorithms cannot be composed. In oracle terms, we give a relativized world where ZQP^{ZQP}\=ZQP, while classically we always have ZPP^{ZPP}=ZPP.
Cite
@article{arxiv.quant-ph/0211029,
title = {Quantum Zero-Error Algorithms Cannot be Composed},
author = {Harry Buhrman and Ronald de Wolf},
journal= {arXiv preprint arXiv:quant-ph/0211029},
year = {2007}
}
Comments
7 pages LaTeX. 2nd version slightly rewritten