Four-Qubit Variational Algorithms in Silicon Photonics with Integrated Entangled Photon Sources

TL;DR

This paper demonstrates the successful implementation of two variational quantum algorithms on a silicon photonic integrated circuit at room temperature, utilizing integrated entangled photon sources for quantum state preparation.

Contribution

First demonstration of variational quantum algorithms on a photonic quantum simulator with integrated photon pair sources at room temperature.

Findings

Executed variational quantum eigensolver for Hydrogen molecule

Performed variational quantum factorization for semi-prime numbers

Used integrated photon pair sources for entangled state preparation

Abstract

Variational quantum algorithms are hybrid quantum-classical approaches extensively studied for their potential to leverage near-term quantum hardware for computational advantages. In this work, we successfully execute two variational quantum algorithms on a silicon photonic integrated circuit at room temperature: a variational quantum eigensolver for the Hydrogen molecule and a variational quantum factorization for semi-prime numbers. In our reconfigurable silicon photonic circuit, four identical spontaneous-four-wave-mixing-based integrated photon pair sources are used to prepare two path-entangled ququarts, whose correlation gives rise to the resource for generic trial states' preparation. This marks a first demonstration of variational quantum algorithms on a photonic quantum simulator with integrated photon pair sources.