A Function-Library Quantum Processor for Boolean Function Evaluation

Version 1 preprint. This manuscript has not undergone peer review. We define the Function-Library Quantum Processor (FLQP), a four-register quantum device that coherently evaluates Boolean functions stored in a quantum register. Given a library of K functions f₀,. . . , f₊-₁: 0, 1ⁿ->0, 1, the FLQP maps |x>X |a>A |F>F |0>Y -> |x>X |a>A |F>F |fₐ (x) >Y, where the function library F is a physical register storing truth tables, not a circuit-level encoding. We give an explicit circuit construction using multi-controlled Toffoli gates, valid for any library.