Automated Synthesis of Quantum Algorithms via Classical Numerical Techniques

TL;DR

This paper introduces a classical numerical optimization framework for automatically synthesizing quantum algorithms, capable of generating quantum circuits from input/output examples, evaluated on single and multi-qubit systems.

Contribution

It presents an end-to-end pipeline combining classical numerical methods with quantum gate decomposition to automate quantum algorithm synthesis from data.

Findings

Effective on single-qubit systems

Capable of synthesizing multi-qubit circuits

Provides an open-source tool for the research community

Abstract

We apply numerical optimization and linear algebra algorithms for classical computers to the problem of automatically synthesizing algorithms for quantum computers. Using our framework, we apply several common techniques from these classical domains and numerically examine their suitability for and performance on this problem. Our methods are evaluated on single-qubit systems as well as on larger systems. While the first part of our proposed method outputs a single unitary matrix representing the composite effects of a quantum circuit or algorithm, we use existing tools - and assess the performance of these - to factor such a matrix into a product of elementary quantum gates. This enables our pipeline to be truly end-to-end: starting from desired input/output examples, our code ultimately results in a quantum circuit diagram. We release our code to the research community (upon acceptance).