arXiv subjects

Antoine Petitjean

Publications and source records attributed to Antoine Petitjean.

7 recordsLinked to original sources

arXiv2026

Temporal limitations and digital data processing in continuous variable measurements of non-Gaussian states

Non-Gaussian quantum states and operations are essential tools for multiple quantum information protocols exploiting light as information career. In this context, a key role is played by schemes operating with continuous wave light, in which non-Gaussian states are obtained by photon subtraction/addition and eventually reconstructed by quantum state tomography. In these configurations, the temporal resolution of the homodyne detection and the digital data processing critically affect our ability to faithfully reconstruct the produced non-Gaussian states. In this work, we apply digital data processing to experimental data to study how the temporal performances of the detection chain affect the acquisition and treatment of tomographic data. This allows understanding how these features impact the quality of quantum states observed by non-ideal detection chains. By doing so, we discuss the actual constraints on the acquisition and reconstruction of non-Gaussian states by taking into account the limitations of realistic experimental resources.

quant-ph↗

arXiv2026

Economical Jet Taggers -- Equivariant, Slim, and Quantized

Modern machine learning is transforming jet tagging at the LHC, but the leading transformer architectures are large, not particularly fast, and training-intensive. We present a slim version of the L-GATr tagger, reduce the number of parameters of jet-tagging transformers, and quantize them. We compare different quantization methods for standard and Lorentz-equivariant transformers and estimate their gains in resource efficiency. We find an order-of-magnitude reduction in energy cost for an moderate performance decrease, down to 1000-parameter taggers. This might be a step towards trigger-level jet tagging with small and quantized versions of the leading equivariant transformer architectures.

hep-ph↗

arXiv2025

Generative Unfolding of Jets and Their Substructure

Unfolding, for example of distortions imparted by detectors, provides suitable and publishable representations of LHC data. Many methods for unbinned and high-dimensional unfolding using machine learning have been proposed, but no generative method scales to the several hundred dimensions necessary to fully characterize LHC collisions. This paper proposes a 3-stage generative unfolding framework that is capable of unfolding several hundred dimensions. It is effective to unfold the jet-level kinematics as well as the full substructure of light-flavor jets and of top jets, and is the first generative unfolding study to achieve high precision on high-dimensional jet substructure.

hep-ph↗

arXiv2024

Quantum Random Access Codes Implementation for Resource Allocation and Coexistence with Classical Telecommunication

In a world where Quantum Networks are rapidly becoming a reality, the development of the Quantum Internet is gaining increasing interest. Nevertheless, modern quantum networks are still in the early stages of development and have limited capacity to distribute resources among different users -- a constraint that needs to be taken into account. In this work we aim to investigate these constraints, using a novel setup for implementing Quantum Random Access Codes (QRACs), communication protocols known for their quantum advantage over their classical counterparts and semi-device-independent self-testing applications. Our QRAC states, made for the first time using weak coherent pulses instead of entangled single photons, allow us to experimentally test our encoding and decoding strategy from the resource allocation perspective. Moreover, by emulating a coexistent classical communication, we test the resilience of our implementation in presence of noise. The achieved results represent a significant milestone both for theoretical studies of quantum resource allocation and for the implementation of quantum infrastructures capable of coexisting with regular telecommunication networks.

quant-ph↗

arXiv2023

Quantum Key Distribution over 100 km underwater optical fiber assisted by a Fast-Gated Single-Photon Detector

Nowadays Quantum Key Distribution represents the most mature quantum technology, and multiple countries as well as private institutions are building their quantum network. However, QKD devices are still far from representing a product within everyone's reach. Indeed, limitations in terms of compatibility with existing telecom infrastructure and limited performances in terms of secret key rate, using non-cryogenic detection systems, are still critical. In this work, we implemented a quantum key distribution link between Sicily (Italy) and Malta utilizing two different Single-Photon Avalanche Diode (SPAD) detectors. The performances of a standard commercial SPAD have been compared with the results achieved with a new prototype of fast-gated System in a Package (SiP) SPAD; the SiP detector has shown to be able to accomplish a fourteen times higher key rate compared with the commercial device over the channel showing 20 dB of losses.

quant-ph↗

arXiv2023

An Integrated Photon-Pair Source with Monolithic Piezoelectric Frequency Tunability

This work demonstrates the capabilities of an entangled photon-pair source at telecom wavelengths, based on a photonic integrated Si$_3$N$_4$ microresonator with monolithically integrated piezoelectric frequency tuning. Previously, frequency tuning of photon-pairs generated by microresonators has only been demonstrated using thermal control, however these have limited actuation bandwidth, and are not compatible with cryogenic environments. Here, the frequency-tunable photon-pair generation capabilities of a Si$_3$N$_4$ microresonator with a monolithically integrated aluminium nitride layer are shown. Fast-frequency locking of the microresonator to an external laser is demonstrated, with a resulting locking bandwidth orders of magnitude larger than reported previously using thermal locking. These abilities will have direct application in future schemes which interface such sources with quantum memories based on e.g. trapped-ion or rare-earth ion schemes.

quant-ph↗

arXiv2022

Plug-&-play generation of non-Gaussian states of light at a telecom wavelength

This work marks an important progress towards practical quantum optical technologies in the continuous variable regime, as it shows the feasibility of experiments where non-Gaussian state generation entirely relies on plug-&-play components from guided-wave optics technologies. This strategy is demonstrated experimentally with the heralded preparation of low amplitude Schrödinger cat states based on single-photon subtraction from a squeezed vacuum. All stages of the experiment are based on off-the-shelf fiber components. This leads to a stable, compact, and easily re-configurable realization, fully compatible with existing fibre networks and, more in general, with future out-of-the-laboratory applications.

quant-ph↗