Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum 2.0 Conference and Exhibition

New approaches to multi-photon quantum interference and entanglement

Shreya Kumar, Alex E. Jones, Daniel Bhatti, Matthias J. Bayerbach, Simone Evaldo D’Aurelio, Nico Hauser, Stefanie Barz

Published Jan 1, 2025• 0 citations
Publisher

Abstract

We study three-photon quantum interference and entanglement using beam splitters, revealing scattering statistics influenced by distinguishability, mixedness, and symmetry. Furthermore, genuine tripartite-entangled states are generated, achieving up to (87.3±1.1)% fidelity, with implications for photonic quantum technologies.
DOI
10.1364/quantum.2025.qth4b.7

Related papers

Experimental entanglement generation using multiport beam splitters

Shreya Kumar, Daniel Bhatti, Alex E. Jones +1 more

Abstract Multipartite entanglement plays a central role in optical quantum technologies. One way to entangle two photons is to prepare them in orthogonal internal states, for example, in two polarisations, and then send them through a balanced beam splitter. Post-selecting on the cases where there is one photon in each output port results in a maximally entangled state. This idea can be extended to schemes for the post-selected generation of larger entangled states. Typically, switching between different types of entangled states requires different arrangements of beam splitters and so a new experimental setup. Here, we demonstrate a simple and versatile scheme to generate different types of genuine tripartite entangled states with only one experimental setup. We send three photons through a three-port splitter and vary their internal states before post-selecting on certain output distributions. This results in the generation of tripartite W, G and GHZ states. We obtain fidelities of up to ( 87.3 ± 1.1 ) % with regard to the respective ideal states, confirming a successful generation of genuine tripartite entanglement.

arXiv:2302.00694•New Journal of Physics•Jun 1, 2023•14 citations

Quantum Entanglement of Photon-Added Coherent States on a Beam Splitter

Dmitry N. Makarov

The study of new quantum states and methods for their generation is an important part of the current development of quantum technologies. One of the most important characteristics of such states is their quantum entanglement. Photon-added coherent states, which are defined as $${\text{|}}\alpha ,n\rangle = {{\mathcal{N}}_{n}}{{({{\hat {a}}^{\dag }})}^{n}}{\text{|}}\alpha \rangle $$ , where $${{\mathcal{N}}_{n}}$$ is the normalization constant, $${\text{|}}\alpha \rangle $$ is the coherent state, $${{\hat {a}}^{\dag }}$$ is the creation operator, and n is the number of added photons, have been introduced relatively recently. The quantum entanglement of such states passing through a beam splitter has been considered for the first time in this work. A simple analytical representation of the wavefunction at the outputs of the beam splitter has been found and the quantum entanglement of the resulting two-qubit states has been considered. It has been shown that new quantum states have good prospects for their use in quantum technologies.

Journal of Experimental and Theoretical Physics Letters•May 1, 2025•0 citations

Distinguishability and mixedness in quantum interference

Alex E. Jones, Shreya Kumar, Simone Evaldo D’Aurelio +3 more

We study the impact of distinguishability and mixedness, two fundamental properties of quantum states, on quantum interference. We show that these can influence the interference of multiple particles in different ways, leading to effects that cannot be observed in the interference of two particles alone. This is demonstrated experimentally by interfering three independent photons in pure and mixed states and observing their different multiphoton interference, despite exhibiting the same two-photon Hong-Ou-Mandel interference. In addition to its fundamental relevance, our observation has important implications for quantum technologies relying on photon interference.

arXiv:2201.04655•Physical Review A•Nov 1, 2023•26 citations

Genuine Tripartite Non-Gaussian Entanglement

Zhang Da, David Barral, Yanpeng Zhang +2 more

Triple-photon states generated by three-mode spontaneous parametric down-conversion are the paradigm of unconditional non-Gaussian states, essential assets for quantum advantage. How to fully characterize their non-Gaussian entanglement remains however elusive. We propose here a set of sufficient and necessary conditions for separability of the broad family of spontaneously generated three-mode non-Gaussian states. We further derive state-of-the-art conditions for genuine tripartite non-Gaussian entanglement, the strongest class of entanglement. We apply our criteria to triple-photon states revealing that they are fully inseparable and genuinely entangled in moments of order 3n. Our results establish a systematic framework for characterizing the entanglement of triple-photon states and thus fostering their application in quantum information protocols.

arXiv:2205.11940•Physical Review Letters•Mar 2, 2023•24 citations

Quantifying tripartite entanglement with entropic correlations

James Schneeloch, Christopher C. Tison, Michael L. Fanto +2 more

The authors develop techniques to quantify multipartite and high-dimensional entanglement using information-based measures of correlation and uncertainty, and show the large amounts of multi-partite entanglement available in photon triplets generated in third-order Spontaneous Parametric Down-Conversion

arXiv:2004.03579•Physical Review Research•Oct 28, 2020•20 citations

Advances in photonic quantum information science

John Rarity

This talk will review recent advances in pair photon sources, multiphoton interference and deterministic entanglement generation commenting on prospects for scalable quantum computation.

European Conference on Optical Communication•Sep 1, 2014•0 citations
Abstract Multipartite entanglement plays a central role in optical quantum technologies. One way to entangle two photons is to prepare them in orthogonal internal states, for example, in two polarisations, and then send them through a balanced beam splitter. Post-selecting on the cases where there is one photon in each output port results in a maximally entangled state. This idea can be extended to schemes for the post-selected generation of larger entangled states. Typically, switching between different types of entangled states requires different arrangements of beam splitters and so a new experimental setup. Here, we demonstrate a simple and versatile scheme to generate different types of genuine tripartite entangled states with only one experimental setup. We send three photons through a three-port splitter and vary their internal states before post-selecting on certain output distributions. This results in the generation of tripartite W, G and GHZ states. We obtain fidelities of up to ( 87.3 ± 1.1 ) % with regard to the respective ideal states, confirming a successful generation of genuine tripartite entanglement.
The study of new quantum states and methods for their generation is an important part of the current development of quantum technologies. One of the most important characteristics of such states is their quantum entanglement. Photon-added coherent states, which are defined as |α,n⟩=Nn(a^†)n|α⟩{\text{|}}\alpha ,n\rangle = {{\mathcal{N}}_{n}}{{({{\hat {a}}^{\dag }})}^{n}}{\text{|}}\alpha \rangle |α,n⟩=Nn​(a^†)n|α⟩ , where Nn{{\mathcal{N}}_{n}}Nn​ is the normalization constant, |α⟩{\text{|}}\alpha \rangle |α⟩ is the coherent state, a^†{{\hat {a}}^{\dag }}a^† is the creation operator, and n is the number of added photons, have been introduced relatively recently. The quantum entanglement of such states passing through a beam splitter has been considered for the first time in this work. A simple analytical representation of the wavefunction at the outputs of the beam splitter has been found and the quantum entanglement of the resulting two-qubit states has been considered. It has been shown that new quantum states have good prospects for their use in quantum technologies.
We study the impact of distinguishability and mixedness, two fundamental properties of quantum states, on quantum interference. We show that these can influence the interference of multiple particles in different ways, leading to effects that cannot be observed in the interference of two particles alone. This is demonstrated experimentally by interfering three independent photons in pure and mixed states and observing their different multiphoton interference, despite exhibiting the same two-photon Hong-Ou-Mandel interference. In addition to its fundamental relevance, our observation has important implications for quantum technologies relying on photon interference.
Triple-photon states generated by three-mode spontaneous parametric down-conversion are the paradigm of unconditional non-Gaussian states, essential assets for quantum advantage. How to fully characterize their non-Gaussian entanglement remains however elusive. We propose here a set of sufficient and necessary conditions for separability of the broad family of spontaneously generated three-mode non-Gaussian states. We further derive state-of-the-art conditions for genuine tripartite non-Gaussian entanglement, the strongest class of entanglement. We apply our criteria to triple-photon states revealing that they are fully inseparable and genuinely entangled in moments of order 3n. Our results establish a systematic framework for characterizing the entanglement of triple-photon states and thus fostering their application in quantum information protocols.