Compilation flow for classically defined quantum operations

Abstract

We present a flow for synthesizing quantum operations that are defined by classical combinational functions. The discussion will focus on out-of-place computation, i.e., U_{f}: x\rangle\vert y\rangle\vert 0\rangle{k}\rightarrow\vert x\rangle\vert y\oplus f(x)\rangle\vert 0\rangle{k}. Our flow allows users to express this function at a high level of abstraction. At its core, there is an improved version of the current state-of-the-art algorithm for synthesizing oracles [1]. As a result, our synthesized circuits use up to 25 % fewer qubits and up to 43 % fewer Clifford gates. Crucially, these improvements are possible without increasing the number of T gates nor the execution time.