Quantum circuits for OR and AND of ORs
Howard Barnum, Herbert Jacob Bernstein, Lee C. Spector · Journal of Physics A Mathematical and General · 2000
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)⊕ f (1)) to give the full set of logical connectives (up to relabelling of inputs and outputs) for which there is quantum speedup.