Demonstration of a Hardware-Independent Toolkit for Automated Quantum Subcircuit Synthesis

Abstract: The quantum computer has become contemporary reality, with the first two-qubit machine of mere decades ago transforming into cloud-accessible devices with tens, hundreds, or -- in a few cases -- even thousands of qubits. While such hardware is noisy and still relatively small, the increasing number of operable qubits raises another challenge: how to develop the now-sizeable quantum circuits executable on these machines. Preparing circuits manually for specifications of any meaningful size is at best tedious and at worst impossible, creating a need for automation. This article describes an automated quantum-software toolkit for synthesis, compilation, and optimization, which transforms classically-specified, irreversible functions into both technology-independent and technology-dependent quantum circuits. We also describe and analyze the toolkit's application to three situations -- quantum read-only memories, quantum random number generators, and quantum oracles -- and illustrate the toolkit's start-to-finish features, from the input of classical functions to the output of technology-dependent quantum circuits. Furthermore, we illustrate how the toolkit enables research beyond circuit synthesis, including comparison of synthesis and optimization methods and deeper understanding of even well-studied quantum algorithms. As quantum hardware continues to develop, such quantum circuit toolkits will play a critical role in realizing its potential.