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A quantum circuit for OR

Howard Barnum·Herbert J. Bernstein·Lee Spector
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Abstract

We give the first quantum circuit for computing $f(0)$ OR $f(1)$ more reliably than is classically possible with a single evaluation of the function. OR therefore joins XOR (i.e. parity, $f(0) \oplus f(1)$) to give the full set of logical connectives (up to relabeling of inputs and outputs) for which there is quantum speedup. The XOR algorithm is of fundamental importance in quantum computation; our OR algorithm (found with the aid of genetic programming), may represent a new quantum computational effect, also useful as a ``subroutine''.

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Howard Barnum, Herbert J. Bernstein, Lee Spector. 1999-10-08. A quantum circuit for OR. https://arxiv.org/abs/quant-ph/9907056

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