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Quantum Zero-Error Algorithms Cannot be Composed

Harry Buhrman·Ronald de Wolf
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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.

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Harry Buhrman, Ronald de Wolf. 2003-07-05. Quantum Zero-Error Algorithms Cannot be Composed. https://arxiv.org/abs/quant-ph/0211029

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