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Related papers: Quantum Pattern Recognition in Photonic Circuits

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We present a novel optical device based on an integrated system of micro-lenses and single mode optical fibers. It allows to collect and direct into many modes two photons generated by spontaneous parametric down conversion. By this device…

Quantum Physics · Physics 2009-04-27 A. Rossi , G. Vallone , A. Chiuri , F. De Martini , P. Mataloni

Linear optical circuits of growing complexity are playing an increasing role in emerging photonic quantum technologies. Individual photonic devices are typically described by a unitary matrix containing amplitude and phase information, the…

Quantum Physics · Physics 2012-08-15 Anthony Laing , Jeremy L. O'Brien

We propose a general methodology for efficient statistical reconstruction of a quantum state through collection and analysis of photon counting statistics. Our approach includes both strict quantitative criteria for adequacy and…

Quantum Physics · Physics 2013-11-07 Yu. I. Bogdanov , S. P. Kulik

Single-photon sources based on semiconductor quantum dots find several applications in quantum information processing due to their high single-photon indistinguishability, on-demand generation, and low multiphoton emission. In this context,…

Accurately estimating the overlap between quantum states is a fundamental task in quantum information processing. While various strategies using distinct quantum measurements have been proposed for overlap estimation, the lack of…

Quantum Physics · Physics 2025-02-13 Hao Zhan , Ben Wang , Minghao Mi , Jie Xie , Liang Xu , Aonan Zhang , Lijian Zhang

Nonclassicality, defined in the quantum optical sense, serves as a resource for photon-based quantum technologies. Therefore, certifying the nonclassicality of a quantum state is crucial for gauging its potential for quantum advantage.…

Quantum state tomography (QST), the process through which the density matrix of a quantum system is characterized from measurements of specific observables, is a fundamental pillar in the fields of quantum information and computation. In…

Quantum Physics · Physics 2024-01-30 J. L. Montenegro Ferreira , B. de Lima Bernardo

We experimentally show that two-photon path-entangled states can be coherently manipulated by multi-mode interference in multi-mode waveguides. By measuring the output two-photon spatial correlation function versus the phase of the input…

Quantum Physics · Physics 2012-08-22 Eilon Poem , Yehonatan Gilead , Yaron Silberberg

We propose an experimentally feasible scheme for generating a two $2\times4\times4$ dimensional photons hyperentangled state, entangled in polarization, frequency and spatial mode. This scheme is mainly based on a parametric down-conversion…

Quantum Physics · Physics 2013-04-30 Hong-Bo Xu , Kun Du , Cong-Feng Qiao

We propose and analyze a multi-functional setup consisting of high finesse optical cavities, beam splitters, and phase shifters. The basic scheme projects arbitrary photonic two-mode input states onto the subspace spanned by the product of…

Quantum Physics · Physics 2015-03-13 Anne E. B. Nielsen , Christine A. Muschik , Geza Giedke , K. G. H. Vollbrecht

The most irreducible way to represent information is a sequence of two symbols. In this paper, we construct quantum states using this basic building block. Specifically, we show that the probabilities that arise in quantum theory can be…

Quantum Physics · Physics 2025-01-28 Sam Powers , Guangpeng Xu , Herbert Fotso , Tim Thomay , Dejan Stojkovic

The complete measurement of the quantum state of two correlated photons requires reconstructing the amplitude and phase of the biphoton wavefunction. We show how, by means of spatially resolved single photon detection, one can infer the…

Quantum Physics · Physics 2025-06-26 Nazanin Dehghan , Alessio D'Errico , Francesco Di Colandrea , Ebrahim Karimi

Recent progress in building large-scale quantum devices for exploring quantum computing and simulation paradigms has relied upon effective tools for achieving and maintaining good experimental parameters, i.e. tuning up devices. In many…

It is a fundamental, but still elusive question whether the schemes based on quantum mechanics, in particular on quantum entanglement, can be used for classical information processing and machine learning. Even partial answer to this…

Machine Learning · Statistics 2022-06-24 Yuhan Liu , Xiao Zhang , Maciej Lewenstein , Shi-Ju Ran

Characterising the input-output photon-number distribution of an unknown optical quantum channel is an important task for many applications in quantum information processing. Ideally, this would require deterministic photon-number sources…

Quantum Physics · Physics 2021-09-14 Emilien Lavie , Ignatius William Primaatmaja , Wen Yu Kon , Chao Wang , Charles Ci Wen Lim

Quantum techniques are expected to revolutionize how information is acquired, exchanged, and processed. Yet it has been a challenge to realize and measure their values in practical settings. We present first photon machine learning as a new…

Quantum Physics · Physics 2024-10-24 Lili Li , Santosh Kumar , Malvika Garikapati , Yu-Ping Huang

We propose a technique for performing quantum state tomography of photonic polarization-encoded multi-qubit states. Our method uses a single rotating wave plate, a polarizing beam splitter and two photon-counting detectors per photon mode.…

Quantum Physics · Physics 2013-01-18 Mohammadreza Mohammadi , Agata M. Branczyk , Daniel F. V. James

The characterization of continuous-variable quantum states is crucial for applications in quantum communication, sensing, simulation and computing. However, a full characterization of multimode quantum states requires a number of…

Quantum Physics · Physics 2024-10-08 Ya-Dong Wu , Yan Zhu , Giulio Chiribella , Nana Liu

We analyze the energy and training data requirements for supervised learning of an $M$-mode linear optical circuit by minimizing an empirical risk defined solely from the action of the circuit on coherent states. When the linear optical…

Quantum Physics · Physics 2023-04-04 T. J. Volkoff , Andrew T. Sornborger

Entanglement--one of the most delicate phenomena in nature--is an essential resource for quantum information applications. Large entangled cluster states have been predicted to enable universal quantum computation, with the required single-…