Quantum Simulation of Electronic Structure using Quantum Density Functional Theory on a Programmable Integrated Photonic Circuit
Abstract
Quantum simulations of molecular electronic structure hold the potential for computational advantage but are inherently limited by the linear scaling of qubit requirements with respect to system size. Quantum Density Functional Theory (Q-DFT) addresses this constraint by reformulating the interacting many-body problem in terms of a non-interacting Kohn--Sham reference system. Here, we present and experimentally validate a Q-DFT algorithm that requires only 𝒪(log2(N)) qubits to simulate a system of N orbitals, thereby reducing resource overhead. More precisely, we solve the Kohn--Sham problem for the lithium hydride (LiH) molecule using the ensemble extension of the variational quantum eigensolver paradigm that minimizes the energy of the system in the subspace spanned by the ground and first excited states. To execute this task, we encode the problem with qubits on a quantum photonic platform, utilizing an architecture that combines a deterministic quantum dot single-photon source with a programmable integrated photonic circuit. By evaluating the molecular ground- and first excited-state properties, this work establishes a pathway for simulating larger molecular systems, demonstrating the viability of integrating qubit-efficient algorithms with advanced reconfigurable photonic hardware for near-term quantum chemistry applications.
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BibTeX
@misc{adriano2026quantum,
title = {{Quantum Simulation of Electronic Structure using Quantum Density Functional Theory on a Programmable Integrated Photonic Circuit}},
author = {Giovanni Adriano and Akilan Rajamani and Francesco Hoch and Farrokh Labib and Nadja Z. Zaouri and Eugenio Caruccio and Gonzalo Carvacho and Nicolò Spagnolo and Riccardo Albiero and Giacomo Corrielli and Francesco Ceccarelli and Jean-Sebastien Filhol and Roberto Osellame and Taira Giordani and Fabio Sciarrino and Nathan Shammah and Bruno Senjean},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04694},
eprint = {2611.04694},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04694},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Quantum Simulation of Electronic Structure using Quantum Density Functional Theory on a Programmable Integrated Photonic Circuit
AU - Giovanni Adriano
AU - Akilan Rajamani
AU - Francesco Hoch
AU - Farrokh Labib
AU - Nadja Z. Zaouri
AU - Eugenio Caruccio
AU - Gonzalo Carvacho
AU - Nicolò Spagnolo
AU - Riccardo Albiero
AU - Giacomo Corrielli
AU - Francesco Ceccarelli
AU - Jean-Sebastien Filhol
AU - Roberto Osellame
AU - Taira Giordani
AU - Fabio Sciarrino
AU - Nathan Shammah
AU - Bruno Senjean
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04694
UR - https://arxiv.org/abs/2611.04694
AB - Quantum simulations of molecular electronic structure hold the potential for computational advantage but are inherently limited by the linear scaling of qubit requirements with respect to system size. Quantum Density Functional Theory (Q-DFT) addresses this constraint by reformulating the interacting many-body problem in terms of a non-interacting Kohn--Sham reference system. Here, we present and experimentally validate a Q-DFT algorithm that requires only 𝒪(log_2(N)) qubits to simulate a system of N orbitals, thereby reducing resource overhead. More precisely, we solve the Kohn--Sham problem for the lithium hydride (LiH) molecule using the ensemble extension of the variational quantum eigensolver paradigm that minimizes the energy of the system in the subspace spanned by the ground and first excited states. To execute this task, we encode the problem with qubits on a quantum photonic platform, utilizing an architecture that combines a deterministic quantum dot single-photon source with a programmable integrated photonic circuit. By evaluating the molecular ground- and first excited-state properties, this work establishes a pathway for simulating larger molecular systems, demonstrating the viability of integrating qubit-efficient algorithms with advanced reconfigurable photonic hardware for near-term quantum chemistry applications.
ER -