Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources

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 circu...

Full description

Saved in:
Bibliographic Details
Main Authors: Alessio Baldazzi, Matteo Sanna, Massimo Borghi, Stefano Azzini, Lorenzo Pavesi
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:npj Quantum Information
Online Access:https://doi.org/10.1038/s41534-025-01061-6
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849238354292375552
author Alessio Baldazzi
Matteo Sanna
Massimo Borghi
Stefano Azzini
Lorenzo Pavesi
author_facet Alessio Baldazzi
Matteo Sanna
Massimo Borghi
Stefano Azzini
Lorenzo Pavesi
author_sort Alessio Baldazzi
collection DOAJ
description 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 semiprime 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.
format Article
id doaj-art-49cc27482fbd4b7eb87eebbd205f169d
institution Kabale University
issn 2056-6387
language English
publishDate 2025-07-01
publisher Nature Portfolio
record_format Article
series npj Quantum Information
spelling doaj-art-49cc27482fbd4b7eb87eebbd205f169d2025-08-20T04:01:40ZengNature Portfolionpj Quantum Information2056-63872025-07-0111111110.1038/s41534-025-01061-6Four-qubit variational algorithms in silicon photonics with integrated entangled photon sourcesAlessio Baldazzi0Matteo Sanna1Massimo Borghi2Stefano Azzini3Lorenzo Pavesi4Department of Physics, University of TrentoDepartment of Physics, University of TrentoDepartment of Physics, University of TrentoDepartment of Physics, University of TrentoDepartment of Physics, University of TrentoAbstract 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 semiprime 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.https://doi.org/10.1038/s41534-025-01061-6
spellingShingle Alessio Baldazzi
Matteo Sanna
Massimo Borghi
Stefano Azzini
Lorenzo Pavesi
Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
npj Quantum Information
title Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
title_full Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
title_fullStr Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
title_full_unstemmed Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
title_short Four-qubit variational algorithms in silicon photonics with integrated entangled photon sources
title_sort four qubit variational algorithms in silicon photonics with integrated entangled photon sources
url https://doi.org/10.1038/s41534-025-01061-6
work_keys_str_mv AT alessiobaldazzi fourqubitvariationalalgorithmsinsiliconphotonicswithintegratedentangledphotonsources
AT matteosanna fourqubitvariationalalgorithmsinsiliconphotonicswithintegratedentangledphotonsources
AT massimoborghi fourqubitvariationalalgorithmsinsiliconphotonicswithintegratedentangledphotonsources
AT stefanoazzini fourqubitvariationalalgorithmsinsiliconphotonicswithintegratedentangledphotonsources
AT lorenzopavesi fourqubitvariationalalgorithmsinsiliconphotonicswithintegratedentangledphotonsources