Papers by Alessandro Zavatta
Generating Discorrelated States for Quantum Information Protocols by Coherent Multimode Photon Addition
Nicola Biagi, Saverio Francesconi, Manuel Gessner, Marco Bellini ∗ , and Alessandro Zavatta ∗ Ist... more Nicola Biagi, Saverio Francesconi, Manuel Gessner, Marco Bellini ∗ , and Alessandro Zavatta ∗ Istituto Nazionale di Ottica (CNR-INO), L.go E. Fermi 6, 50125 Florence, Italy LENS and Department of Physics & Astronomy, University of Firenze, 50019 Sesto Fiorentino, Florence, Italy Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, 24 Rue Lhomond, 75005, Paris, France (Dated: August 27, 2021)
Single-Photon-Added Coherent States of Light Quantum-to-Classical Transition with
Single Photon Detectors's Timing-Jitter Quantum Description
We model single photon detectors by explicitly taking into account their timing-jitter, finite ef... more We model single photon detectors by explicitly taking into account their timing-jitter, finite efficiency and dead-time effects. Our model represents the first operational and full description of temporal limitations of those detectors. © 2019 The Author(s)
Front Cover: Generating Discorrelated States for Quantum Information Protocols by Coherent Multimode Photon Addition (Adv. Quantum Technol. 5/2021)
Advanced Quantum Technologies
Journal of Physics B: Atomic, Molecular and Optical Physics
Conventional spectroscopy uses classical light to detect matter properties through the variation ... more Conventional spectroscopy uses classical light to detect matter properties through the variation of its response with frequencies or time delays. Quantum light opens up new avenues for spectroscopy by utilizing parameters of the quantum state of light as novel control knobs and through the variation of photon statistics by coupling to matter. This Roadmap article focuses on using quantum light as a powerful sensing and spectroscopic tool to reveal novel information about complex molecules that is not accessible by classical light. It aims at bridging the quantum optics and spectroscopy communities which normally have opposite goals: manipulating complex light states with simple matter e.g. qubits versus studying complex molecules with simple classical light, respectively. Articles cover advances in the generation and manipulation of state-of-the-art quantum light sources along with applications to sensing, spectroscopy, imaging and interferometry.
Photonics Research
We demonstrate a squeezing experiment exploiting the association of integrated optics and telecom... more We demonstrate a squeezing experiment exploiting the association of integrated optics and telecom technology as key features for compact, stable, and practical continuous variable quantum optics. In our setup, squeezed light is generated by single pass spontaneous parametric down conversion on a lithium niobate photonic circuit and detected by an homodyne detector whose interferometric part is directly integrated on the same platform. The remaining parts of the experiment are implemented using commercial plug-and-play devices based on guided-wave technologies. We measure, for a CW pump power of 40 mW, a squeezing level of −2.00 ± 0.05 dB, (antisqueezing +2.80 ± 0.05 dB) thus confirming the validity of our approach and opening the way toward miniaturized and easy-to-handle continuous variable based quantum systems.
Zero Area Single Photons
Latin America Optics and Photonics Conference, 2016
A fully guided-wave approach to the generation and detection of squeezing at a telecom wavelength
Conference on Lasers and Electro-Optics, 2016
We report on the first realization of an entirely guided-wave squeezing experiment at telecom wav... more We report on the first realization of an entirely guided-wave squeezing experiment at telecom wavelength. Our setup exploits non-linear optical waveguides and fiber components. This configuration allows implementing a plug-and-play experiment, compatible with fiber networks.
Probing Quantum Rules with Single-Photon Creation and Annihilation Operators
We experimentally apply simple sequences of photon creation and annihilation operators to a light... more We experimentally apply simple sequences of photon creation and annihilation operators to a light field. By a tomographic analysis of the resulting light states we provide the first direct test of quantum non-commutativity.
Mid-infrared balanced detector for characterization of quantum light
OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES)
Entropy
We present a concise review of recent experimental results concerning the conditional implementat... more We present a concise review of recent experimental results concerning the conditional implementation of coherent superpositions of single-photon additions onto distinct field modes. Such a basic operation is seen to give rise to a wealth of interesting and useful effects, from the generation of a tunable degree of entanglement to the birth of peculiar correlations in the photon numbers and the quadratures of multimode, multiphoton, states of light. The experimental investigation of these properties will have an impact both on fundamental studies concerning, for example, the quantumness and entanglement of macroscopic states, and for possible applications in the realm of quantum-enhanced technologies.
Mid-infrared homodyne balanced detector for quantum light characterization
Optics Express
Physical Review A
Efficient heralded generation of entanglement together with its manipulation is of great importan... more Efficient heralded generation of entanglement together with its manipulation is of great importance for quantum communications. In addition, states generated with bandwidths naturally compatible with atomic transitions allow a more efficient mapping of light into matter which is an essential requirement for long distance quantum communications. Here we propose a scheme where the indistinguishability between two spontaneous four-wave mixing processes is engineered to herald generation of single-photon frequency-bin entangled states, i.e. single-photons shared by two distinct frequency modes. We show that entanglement can be optimised together with the generation probability, while maintaining absorption negligible. Besides, the scheme illustrated for cold rubidium atoms is versatile and can be implemented in several other physical systems.
Physical Review Letters
We present the experimental generation of tunable entanglement between distinct field modes by th... more We present the experimental generation of tunable entanglement between distinct field modes by the delocalized addition of a single photon. We show that one can preserve a high degree of entanglement even between macroscopically populated modes and illustrate this concept by adding a single photon to two modes containing identical coherent states of growing amplitude. Discorrelation, a new joint statistical property of multimode quantum states, is also experimentally demonstrated here for the first time.
IEEE Journal of Selected Topics in Quantum Electronics
High-dimensional quantum states have already settled their advantages in different quantum techno... more High-dimensional quantum states have already settled their advantages in different quantum technology applications. However, their reliable transmission in fiber links remains an open challenge that must be addressed to boost their application, e.g. in the future quantum internet. Here, we prove how path encoded high-dimensional quantum states can be reliably transmitted over a 2 km long multicore fiber, taking advantage of a phase-locked loop system guaranteeing a stable interferometric detection.
New Journal of Physics
We suggest and demonstrate a tomographic method to characterise homodyne detectors at the quantum... more We suggest and demonstrate a tomographic method to characterise homodyne detectors at the quantum level. The positive operator measure associated with the detector is expanded in a quadrature basis and probed with a set of coherent states. The coefficients of the expansion are then retrieved using a least squares algorithm. Our model is general enough to describe different implementations of the homodyne setup, and it has proven capable of effectively describing the detector response to different tomographic sets. We validate the reconstructed operator measure on nonclassical states and exploit results to estimate the overall quantum efficiency of the detector.
Physical review letters, Jan 7, 2017
Strong nonlinearity at the single photon level represents a crucial enabling tool for optical qua... more Strong nonlinearity at the single photon level represents a crucial enabling tool for optical quantum technologies. Here we report on experimental implementation of a strong Kerr nonlinearity by measurement-induced quantum operations on weak quantum states of light. Our scheme coherently combines two sequences of single photon addition and subtraction to induce a nonlinear phase shift at the single photon level. We probe the induced nonlinearity with weak coherent states and characterize the output non-Gaussian states with quantum state tomography. The strong nonlinearity is clearly witnessed as a change of sign of specific off-diagonal density matrix elements in the Fock basis.
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Papers by Alessandro Zavatta