Quantum and Linear-Optical Computation
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Quantum and Linear-Optical Computation
Quantum information science has the potential to revolutionize information processing, in the form of dramatically faster quantum algorithms and novel protocols for cryptography, metrology, and sensing. The Quantum and Linear-Optical Computation group explores the features of quantum theory that enable advantage in quantum information processing tasks, in particular, those present in photonic implementations of quantum computers. There is not a single way to harness these quantum effects, so studying different models of quantum computation enables us to pinpoint different ways to get quantum systems to work their magic.
Our group has 3 main research lines:
1. Foundations of quantum computation
- Quantification of resources for quantum computational advantage: quantum contextuality, coherence, non-locality, adaptivity, etc.
- Optimizing different models of quantum computation, especially for the current regime of Noisy, Intermediate-scale Quantum (NISQ) devices: measurement-based quantum computation, variational quantum algorithms, Bayesian methods and machine learning for device characterization and metrology.
2. Photonic quantum computation
- Requirements for scalable photonic quantum computation;
- Characterization of multiphoton indistinguishability;
- Computational uses for complex, reconfigurable multi-mode interferometers;
- Classical simulation algorithms.
3. Quantum software engineering
- Semantic structures able to comply with different types of classical control (non-deterministic, probabilistic, continuous) and quantum data;
- Algorithmic calculi stemming from the semantics above for the systematic derivation of quantum programs in a compositional way;
- Dynamic logics for the quantum domain to support the formulation of contracts for quantum algorithms and their compositional verification;
- Compositional methods for coordination of distributed quantum computational systems — a main requirement for obtaining optimally responsive global quantum networks.
Multimode interferometers are a special type of photonic quantum computer.
ON GOING RESEARCH PROJECTS
- Resources for quantum computational speed-up in topological, measurement-based, and circuit-based quantum computation.
- Experimentally-friendly characterization of multi-photon indistinguishability
- Quantum computation with integrated photonic chips
PUBLICATIONS
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2022
Rui Soares Barbosa, T. Douce, Pierre-Emmanuel Emeriau, E. Kashefi, Shane Mansfield
Continuous-Variable Nonlocality and Contextuality Journal Article
COMMUNICATIONS IN MATHEMATICAL PHYSICS, 2022.
@article{Barbosa2022,
title = {Continuous-Variable Nonlocality and Contextuality},
author = {Rui Soares Barbosa, T. Douce, Pierre-Emmanuel Emeriau, E. Kashefi, Shane Mansfield},
doi = {10.1007/s00220-021-04285-7},
year = {2022},
date = {2022-03-31},
journal = {COMMUNICATIONS IN MATHEMATICAL PHYSICS},
abstract = {Contextuality is a non-classical behaviour that can be exhibited by quantum systems. It is increasingly studied for its relationship to quantum-over-classical advantages in informatic tasks. To date, it has largely been studied in discrete-variable scenarios, where observables take values in discrete and usually finite sets. Practically, on the other hand, continuous-variable scenarios offer some of the most promising candidates for implementing quantum computations and informatic protocols. Here we set out a framework for treating contextuality in continuous-variable scenarios. It is shown that the Fine-Abramsky-Brandenburger theorem extends to this setting, an important consequence of which is that Bell nonlocality can be viewed as a special case of contextuality, as in the discrete case. The contextual fraction, a quantifiable measure of contextuality that bears a precise relationship to Bell inequality violations and quantum advantages, is also defined in this setting. It is shown to be a non-increasing monotone with respect to classical operations that include binning to discretise data. Finally, we consider how the contextual fraction can be formulated as an infinite linear program. Through Lasserre relaxations, we are able to express this infinite linear program as a hierarchy of semi-definite programs that allow to calculate the contextual fraction with increasing accuracy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Contextuality is a non-classical behaviour that can be exhibited by quantum systems. It is increasingly studied for its relationship to quantum-over-classical advantages in informatic tasks. To date, it has largely been studied in discrete-variable scenarios, where observables take values in discrete and usually finite sets. Practically, on the other hand, continuous-variable scenarios offer some of the most promising candidates for implementing quantum computations and informatic protocols. Here we set out a framework for treating contextuality in continuous-variable scenarios. It is shown that the Fine-Abramsky-Brandenburger theorem extends to this setting, an important consequence of which is that Bell nonlocality can be viewed as a special case of contextuality, as in the discrete case. The contextual fraction, a quantifiable measure of contextuality that bears a precise relationship to Bell inequality violations and quantum advantages, is also defined in this setting. It is shown to be a non-increasing monotone with respect to classical operations that include binning to discretise data. Finally, we consider how the contextual fraction can be formulated as an infinite linear program. Through Lasserre relaxations, we are able to express this infinite linear program as a hierarchy of semi-definite programs that allow to calculate the contextual fraction with increasing accuracy. -
2021
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2020
Ernesto F Galvão and Daniel J Brod
Quantum and classical bounds for two-state overlaps Journal Article
Physical Review A, 101 , pp. 062110, 2020, ISSN: 2469-9934.
@article{GalvaoB20,
title = {Quantum and classical bounds for two-state overlaps},
author = {Ernesto F Galvão and Daniel J Brod},
url = {https://doi.org/10.1103/PhysRevA.101.062110},
doi = {10.1103/PhysRevA.101.062110},
issn = {2469-9934},
year = {2020},
date = {2020-06-19},
journal = {Physical Review A},
volume = {101},
pages = {062110},
abstract = {Suppose we have N quantum systems in unknown states |ψi⟩, but we know the value of some pairwise overlaps |⟨ψ_k|ψ_l⟩|^2. What can we say about the values of the unknown overlaps? We provide a complete answer to this problem for three pure states and two given overlaps and a way to obtain bounds for the general case. We discuss how the answer contrasts from that of a classical model featuring only coherence-free, diagonal states, and we describe three applications: basis-independent coherence witnesses, dimension witnesses, and characterization of multiphoton indistinguishability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Suppose we have N quantum systems in unknown states |ψi⟩, but we know the value of some pairwise overlaps |⟨ψ_k|ψ_l⟩|^2. What can we say about the values of the unknown overlaps? We provide a complete answer to this problem for three pure states and two given overlaps and a way to obtain bounds for the general case. We discuss how the answer contrasts from that of a classical model featuring only coherence-free, diagonal states, and we describe three applications: basis-independent coherence witnesses, dimension witnesses, and characterization of multiphoton indistinguishability.Chiara Esposito Niko Viggianiello Marco Romano Fulvio Flamini Gonzalo Carvacho Nicolò Spagnolo Ernesto Galvão F Taira Giordani Daniel J Brod and Fabio Sciarrino
Experimental quantification of four-photon indistinguishability Journal Article
New Journal of Physics, 22 , pp. 043001, 2020, ISSN: 1367-2630.
@article{Giordani20,
title = {Experimental quantification of four-photon indistinguishability},
author = {Chiara Esposito Niko Viggianiello Marco Romano Fulvio Flamini Gonzalo Carvacho Nicolò Spagnolo Ernesto Galvão F Taira Giordani Daniel J Brod and Fabio Sciarrino},
url = {https://iopscience.iop.org/article/10.1088/1367-2630/ab7a30},
doi = {10.1088/1367-2630/ab7a30},
issn = {1367-2630},
year = {2020},
date = {2020-04-02},
journal = {New Journal of Physics},
volume = {22},
pages = {043001},
abstract = {Photon indistinguishability plays a fundamental role in information processing, with applications such as linear-optical quantum computation and metrology. It is then necessary to develop appropriate tools to quantify the amount of this resource in a multiparticle scenario. Here we report a four-photon experiment in a linear-optical interferometer designed to simultaneously estimate the degree of indistinguishability between three pairs of photons. The interferometer design dispenses with the need of heralding for parametric down-conversion sources, resulting in an efficient and reliable optical scheme. We then use a recently proposed theoretical framework to quantify genuine four-photon indistinguishability, as well as to obtain bounds on three unmeasured two-photon overlaps. Our findings are in high agreement with the theory, and represent a new resource-effective technique for the characterization of multiphoton interference.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Photon indistinguishability plays a fundamental role in information processing, with applications such as linear-optical quantum computation and metrology. It is then necessary to develop appropriate tools to quantify the amount of this resource in a multiparticle scenario. Here we report a four-photon experiment in a linear-optical interferometer designed to simultaneously estimate the degree of indistinguishability between three pairs of photons. The interferometer design dispenses with the need of heralding for parametric down-conversion sources, resulting in an efficient and reliable optical scheme. We then use a recently proposed theoretical framework to quantify genuine four-photon indistinguishability, as well as to obtain bounds on three unmeasured two-photon overlaps. Our findings are in high agreement with the theory, and represent a new resource-effective technique for the characterization of multiphoton interference. -
2019
Allan D C Tosta and Daniel J Brod and Ernesto F Galvão.
Quantum computation from fermionic anyons on a 1D lattice Journal Article
Physical Review A, 99 , pp. 062335, 2019.
@article{Tosta2019,
title = {Quantum computation from fermionic anyons on a 1D lattice},
author = {Allan D C Tosta and Daniel J Brod and Ernesto F Galvão.},
url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.99.062335},
doi = {https://doi.org/10.1103/PhysRevA.99.062335},
year = {2019},
date = {2019-07-27},
journal = {Physical Review A},
volume = {99},
pages = {062335},
abstract = {Fermionic linear optics corresponds to the dynamics of free fermions and is known to be efficiently simulable classically. We define fermionic anyon models by deforming the fermionic algebra of creation and annihilation operators, and consider the dynamics of number-preserving, quadratic Hamiltonians on these operators. We show that any such deformation results in an anyonic linear-optical model which allows for universal quantum computation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Fermionic linear optics corresponds to the dynamics of free fermions and is known to be efficiently simulable classically. We define fermionic anyon models by deforming the fermionic algebra of creation and annihilation operators, and consider the dynamics of number-preserving, quadratic Hamiltonians on these operators. We show that any such deformation results in an anyonic linear-optical model which allows for universal quantum computation.D J Brod and E F Galvão and A Crespi and R Osellame and N Spagnolo and F Sciarrino.
Photonic implementation of boson sampling: a review Journal Article
Advanced Photonics, 1 (3), pp. 034001, 2019.
@article{Brod2019,
title = {Photonic implementation of boson sampling: a review},
author = {D J Brod and E F Galvão and A Crespi and R Osellame and N Spagnolo and F Sciarrino.},
doi = {https://doi.org/10.1117/1.AP.1.3.034001},
year = {2019},
date = {2019-06-25},
journal = {Advanced Photonics},
volume = {1},
number = {3},
pages = {034001},
abstract = {Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved by dedicated photonic quantum hardware, comprising single photons, linear evolution, and photodetection. This prospect has stimulated much effort resulting in the experimental implementation of progressively larger devices. We review recent advances in photonic boson sampling, describing both the technological improvements achieved and the future challenges. We also discuss recent proposals and implementations of variants of the original problem, theoretical issues occurring when imperfections are considered, and advances in the development of suitable techniques for validation of boson sampling experiments. We conclude by discussing the future application of photonic boson sampling devices beyond the original theoretical scope.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved by dedicated photonic quantum hardware, comprising single photons, linear evolution, and photodetection. This prospect has stimulated much effort resulting in the experimental implementation of progressively larger devices. We review recent advances in photonic boson sampling, describing both the technological improvements achieved and the future challenges. We also discuss recent proposals and implementations of variants of the original problem, theoretical issues occurring when imperfections are considered, and advances in the development of suitable techniques for validation of boson sampling experiments. We conclude by discussing the future application of photonic boson sampling devices beyond the original theoretical scope.Pinheiro B da Silva and D S Tasca and E F Galvão and A Z Khoury
Astigmatic tomography of orbital-angular-momentum superpositions Journal Article
Physical Review A, 99 , pp. 043820, 2019.
@article{daSilva2019,
title = {Astigmatic tomography of orbital-angular-momentum superpositions},
author = {Pinheiro B da Silva and D S Tasca and E F Galvão and A Z Khoury},
doi = {https://doi.org/10.1103/PhysRevA.99.043820},
year = {2019},
date = {2019-04-16},
journal = {Physical Review A},
volume = {99},
pages = {043820},
abstract = {We use astigmatic transformations to characterize two-dimensional superpositions of orbital-angular-momentum states in laser beams. We propose two methods for doing this, both relying only on astigmatic transformations, viewed as rotations on the Poincaré sphere, followed by imaging. These methods can be used as a tomographic tool for communication protocols based on optical vortices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}We use astigmatic transformations to characterize two-dimensional superpositions of orbital-angular-momentum states in laser beams. We propose two methods for doing this, both relying only on astigmatic transformations, viewed as rotations on the Poincaré sphere, followed by imaging. These methods can be used as a tomographic tool for communication protocols based on optical vortices.D J Brod and E F Galvão and N Viggianiello and F Flamini and N Spagnolo and F Sciarrino
Witnessing genuine multiphoton indistinguishability Journal Article
Physical Review Letters, 122 , pp. 063602, 2019.
@article{Brod2019b,
title = {Witnessing genuine multiphoton indistinguishability},
author = {D J Brod and E F Galvão and N Viggianiello and F Flamini and N Spagnolo and F Sciarrino},
doi = {https://doi.org/10.1103/PhysRevLett.122.063602},
year = {2019},
date = {2019-02-13},
journal = {Physical Review Letters},
volume = {122},
pages = {063602},
abstract = {Bosonic interference is a fundamental physical phenomenon, and it is believed to lie at the heart of quantum computational advantage. It is thus necessary to develop practical tools to witness its presence, both for a reliable assessment of a quantum source and for fundamental investigations. Here we describe how linear interferometers can be used to unambiguously witness genuine
n-boson indistinguishability. The amount of violation of the proposed witnesses bounds the degree of multiboson indistinguishability, for which we also provide a novel intuitive model using set theory. We experimentally implement this test to bound the degree of three-photon indistinguishability in states we prepare using parametric down-conversion. Our approach results in a convenient tool for practical photonic applications, and may inspire further fundamental advances based on the operational framework we adopt.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Bosonic interference is a fundamental physical phenomenon, and it is believed to lie at the heart of quantum computational advantage. It is thus necessary to develop practical tools to witness its presence, both for a reliable assessment of a quantum source and for fundamental investigations. Here we describe how linear interferometers can be used to unambiguously witness genuine
n-boson indistinguishability. The amount of violation of the proposed witnesses bounds the degree of multiboson indistinguishability, for which we also provide a novel intuitive model using set theory. We experimentally implement this test to bound the degree of three-photon indistinguishability in states we prepare using parametric down-conversion. Our approach results in a convenient tool for practical photonic applications, and may inspire further fundamental advances based on the operational framework we adopt. -
2018
N Viggianiello and F Flamini and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino
Optimal photonic indistinguishability tests in multimode networks Journal Article
Science Bulletin, 63 (22), pp. 1470, 2018.
@article{Viggianiello2018,
title = {Optimal photonic indistinguishability tests in multimode networks},
author = {N Viggianiello and F Flamini and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino},
url = {https://www.sciencedirect.com/science/article/pii/S2095927318305061},
doi = {https://doi.org/10.1016/j.scib.2018.10.009},
year = {2018},
date = {2018-11-30},
journal = {Science Bulletin},
volume = {63},
number = {22},
pages = {1470},
abstract = {Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications such as linear optical quantum computation and simulation, in particular for Boson Sampling devices. It is thus crucial to develop tools to certify genuine multiphoton interference between multiple sources. Our approach employs the total variation distance to find those transformations that minimize the error probability in discriminating the behaviors of distinguishable and indistinguishable photons. In particular, we show that so-called Sylvester interferometers are near-optimal for this task. By using Bayesian tests and inference, we numerically show that Sylvester transformations largely outperform most Haar-random unitaries in terms of sample size required. Furthermore, we experimentally demonstrate the efficacy of the transformation using an efficient 3D integrated circuits in the single- and multiple-source cases. We then discuss the extension of this approach to a larger number of photons and modes. These results open the way to the application of Sylvester interferometers for optimal assessment of multiphoton interference experiments.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications such as linear optical quantum computation and simulation, in particular for Boson Sampling devices. It is thus crucial to develop tools to certify genuine multiphoton interference between multiple sources. Our approach employs the total variation distance to find those transformations that minimize the error probability in discriminating the behaviors of distinguishable and indistinguishable photons. In particular, we show that so-called Sylvester interferometers are near-optimal for this task. By using Bayesian tests and inference, we numerically show that Sylvester transformations largely outperform most Haar-random unitaries in terms of sample size required. Furthermore, we experimentally demonstrate the efficacy of the transformation using an efficient 3D integrated circuits in the single- and multiple-source cases. We then discuss the extension of this approach to a larger number of photons and modes. These results open the way to the application of Sylvester interferometers for optimal assessment of multiphoton interference experiments.Neves, and L. S. Barbosa
Languages and models for hybrid automata: A coalgebraic perspective Journal Article
Theoretical Computer Science, Elsevier, 744 , pp. 113-142, 2018.
@article{Neves2018,
title = {Languages and models for hybrid automata: A coalgebraic perspective},
author = {Neves, and L. S. Barbosa},
doi = {10.1016/j.tcs.2017.09.038},
year = {2018},
date = {2018-09-21},
journal = {Theoretical Computer Science, Elsevier},
volume = {744},
pages = {113-142},
abstract = {We study hybrid automata from a coalgebraic point of view. We show that such a perspective supports a generic theory of hybrid automata with a rich palette of definitions and results. This includes, among other things, notions of bisimulation and behaviour, state minimisation techniques, and regular expression languages.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}We study hybrid automata from a coalgebraic point of view. We show that such a perspective supports a generic theory of hybrid automata with a rich palette of definitions and results. This includes, among other things, notions of bisimulation and behaviour, state minimisation techniques, and regular expression languages.N Viggianiello and F Flamini and L Innocenti and D Cozzolino and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino
Experimental generalized quantum suppression law in Sylvester interferometers Journal Article
New Journal of Physics, 20 , pp. 033017, 2018.
@article{Viggianiello2018b,
title = {Experimental generalized quantum suppression law in Sylvester interferometers},
author = {N Viggianiello and F Flamini and L Innocenti and D Cozzolino and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino},
url = {https://iopscience.iop.org/article/10.1088/1367-2630/aaad92},
doi = {https://doi.org/10.1088/1367-2630/aaad92},
year = {2018},
date = {2018-03-26},
journal = {New Journal of Physics},
volume = {20},
pages = {033017},
abstract = {Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling devices. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong–Ou–Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression occurs for a much larger fraction of input–output combinations than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference, such as quantum simulation and quantum metrology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling devices. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong–Ou–Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression occurs for a much larger fraction of input–output combinations than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference, such as quantum simulation and quantum metrology.
OTHER
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Scholarships, grants and prizes
2019-2022 CNPq Productivity in Research Grant, level 2.
2016-2019 CNPq Productivity in Research Grant, level 2.
2016 Former PhD student Daniel J. Brod awarded honourific mention at José Leite Lopes Prize for best PhD thesis in physics awarded in 2014 (Brazilian Physics Society).
2011 Teacher Homage recipient at the 2011.1 and 2011.2 graduation ceremonies for the IF-UFF Physics classes.
2011 Co-organizer of the III Quantum Information School and Workshop – Paraty 2011. I was the coordinator of the APQ2/FAPERJ grant (total value: approx. 10000 reais).
2007 Co-organizer of the Paraty07 Quantum Information School/Workshop. I was the coordinator of the CLAF and APQ2/FAPERJ grants (total value: approx. 14000 reais).
2006 FAPERJ grant Programa Primeiros Projetos. Value: R$12500.
2006 CAPES PRODOC post-doctoral scholarship.
2005-2006 CNPq junior postdoctoral scholarship.
2004 Approved in selection process (`concurso´) for assistant professor at the UNICAMP Physics Institute. 10 a 12/2/2004.
2002-2005 Postdoctoral Fellowship at the Perimeter Institute for Theoretical Physics.
1999 – 2001 Overseas Research Students (ORS) Award from Universities UK (worth roughly £12000).
1998 – 2002 Ph.D. scholarship for study abroad from the Brazilian agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
1996 – 1998 Master‘s degree scholarship from CAPES.
1995 Tutorship scholarship, PUC-Rio.
1992-1995 Full tuition Academic Performance scholarship, PUC-Rio.
1992-1994 Undergraduate Research Programme scholarship (´Iniciação Científica´) by the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CnPq).
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Teaching and academic supervision
2016- supervision of doctorate student Allan Tosta.
2014-2015 supervision of undergrad student Lucas Lima (undergrad research project).
2013-2015 supervision of students André Oestereich (Master’s degree), and Bárbara Santos and Allan Tosta in undergrad research projects.
2009 – 2014 – supervision of doctorate student Daniel Brod.
2008-2013 supervision of doctorate student Raphael Silva.
2008-2009 supervision of postdoc Rômulo Abreu.
2005- Undergraduate teaching: Basic Physics II and III; Quantum Mechanics I and II; Classical Mechanics I; Electromagnetism I and II, Experimental Physics Laboratory II. Graduate teaching: Quantum Information and Quantum Computation I, Quantum Mechanics I.
2003-2004 Co-supervision of undergraduate research project of student Aissa Stein, University of Waterloo (jointly with Lee Smolin).
2002 Co-supervised award-winning summer project of student Hilary Greaves at Clarendon Laboratory, Oxford (with Lucien Hardy).
2000, 2001 Tutor in two one-week long physics courses for gifted A-level (secondary) students. Villiers Park Educational Trust (United Kingdom).
1995 Volunteer tutor for poor students aiming at passing the university entrance exam. André Maurois school, Rio de Janeiro.
1995 Tutor in “Physics for Arts” course at PUC-Rio.
1995 Tutor in exercise classes for basic physics course (Physics II), PUC-Rio.
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Conferences and workshops
2018 XXXVIII Congresso Nacional de Matemática Aplicada e Computacional (CNMAC), invited talk “Quantum and classical equality testing” in Mini-symposium “Mathematics of Quantum Mechanics”. (September 17-21).
2017 Workshop “Quantum correlations, contextuality and all that, again and again”, International Institute of Physics, Natal. Invited talk: “Reliable computation from contextual correlations” (Nov. 20-24).
2016 XXXIX Encontro Nacional de Física da Matéria Condensada. Invited talk: Quantum computation with photonic chips.
2015 Workshop PICQUE Roma Scientific School 2015. Invited talk: Boson Sampling – a bit of theory.
2015 Workshop “Quantum Correlations, Contextuality, and All That Again”, International Institute of Physics, Natal. Invited talk: “Computing with contextual correlations”.
2015 V Paraty Quantum Information Workshop. Invited talk: Boson sampling in photonic chips.
2015 XXXVIII Encontro Nacional de Física da Matéria Condensada. Invited talk: Boson Sampling in integrated photonic chips.
2015 V Workshop em Comunicação e Informação Quântica (Campina Grande, Paraíba, Brazil, March). Invited talk: Boson sampling in photonic chips.
2014 Meeting: O Pote de Ouro de Bell – 50 anos das desigualdades de Bell. Invited talk: Não-localidade além da mecânica quântica.
2014 Talk “Boson Sampling in photonic chips” at the conferece Quantum Optics VII – Mar del Plata, Argentina (October).
2014 Invited talk at 1-day symposium “O Pote de Ouro de Bell – 50 anos das desigualdades de Bell”, CBPF, 5/12/2014.
2013 Seminário convidado no workshop “Quantum information seen through closed timelike curves”, Fondation des Treilles, França (junho).
2013 Invited talk at the “Quantum information seen through closed timelike curves” workhop in France, Fondation des Treilles (June).
2013 Invited talk at the Quantum Information Workshop – Paraty 2013 (Paraty, Brazil, August).
2011 Poster at Quantum Information Processing Workshop – QIP2012, Montréal, Canada, December.
2011 Talk at the 5th Feynman Festival (May), Foz do Iguaçu, Brazil.
2010 Talk at the Workshop on Quantum Algorithms, Computational Models and Foundations of Quantum Mechanics (QAMF), Vancouver, Canada, 23-25/7/2010.
2010 Poster presentation at Quantum Information Processing Workshop (QIP) 2010, Zurich, Switzerland.
2009 Invited speaker at the XV Escola Regional de Informática – Paraná, with talks in Curitiba and Bandeirantes.
2009 Invited speaker at SEMISH 2009, part of the XXIX Congresso da Sociedade Brasileira de Computação.
2009 Talk at Paraty09 – Quantum Information Workshop.
2008 Poster presentation at Quantum Optics IV – Florianópolis.
2006 Talk at the Young Researchers Symposium of the International Congress on Mathematical Physics – ICMP 2006. IMPA, Rio de Janeiro, 04/08 to 11/08.
2006 Talk at the Workshop on Theory and Technology in Quantum Information, Communication, Computation and Cryptography, Trieste, 19-23rd June.
2005 Talk at the Quantum Physics of Nature & 6th European QIPC Workshop, Vienna. May 22nd-26th.
2004 Quantum Information Theory: Present Status and Future Directions workshop, Isaac Newton Institute, Cambridge (U.K.), 23-27 August.
2004 Quantum computing, Quantum Information, Quantum Gravity workshop, Perimeter Institute, Waterloo (Canada), February 23-27th.
2004 QIP 2004 – The Seventh Workshop on Quantum Information Processing. Waterloo, Canada, January 15-19th.
2003 Pan American Advanced Studies Institute on the Physics of Information, Búzios, Brazil, December 4-9th.
2003 Quantum Information and Communication workshop in the Benasque Center for Science, Spain, June 22 – July 13.
2002 Talk at the IUPAP International Conference on “Quantum Entanglement, Complexity and the Physical Basis for Quantum Computation“, CBPF, Rio de Janeiro, Brazil, December 2-6.
2002 Poster presentation at the EURESCO Conference on quantum information: quantum entanglement. San Feliu de Guixols, Spain, March 23-28.
2002 Poster presentation at the International Conference on Quantum information: conceptual foundations. University of Oviedo, Spain, July 13-18.
2002 Poster presentation at QRANDOM II Conference at the Max Planck Institute- Dresden (27/01 to 02/02).
2001 Talk in open session of Fourth Workshop on Quantum Information Processing. CWI, Amsterdam, January 9-12.
2000 Poster presentation at Fifth International Conference on Quantum Communication, Measurement & Computing. Capri, Italy, July 3-8.
1999 8th U.K. Foundations of Physics meeting. 13/9 to 17/9/1999.
1999 Newton Institute workshop on Complexity, Computation and the Physics of Information (Cambridge). 5/7 to 17/7/99.
1998 Jorge André Swieca Summer School on Quantum and non-linear Optics (São Carlos, Brazil). 05/01/1998 to 16/01/1998.
1996,1997 Two summer courses at the Mathematics Department, PUC-Rio, on Information Theory and Discrete Mathematics. 12/02/96 to 16/02/96, 17/02/97 to 28/02/97.
1993,1995 Lafex International Schools on High Energy Physics (LISHEP‘93 and LISHEP‘95), organized by LAFEX – CBPF. 24/01/93 to 13/02/93 and 06/02/95 to 22/02/95.
1992-1994 Pursued an undergraduate research project in the High-Energy Physics and Cosmology Laboratory of the Brazilian Centre for Physical Research (LAFEX- CBPF).
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Other Activities
2019 Participation in the examination committee (president) to select an adjunct professor at the Physics Institute of Universidade de São Paulo (USP).
2019 Program committee of The 14th Conference on the Theory of Quantum Computation, Communication, and Cryptography – TQC 2019.
2018 Short course “Introduction to quantum computation and simulability” at ICTP-SAIFR/IFT-UNESP (São Paulo), jointly with Daniel Brod and Leandro Aolita. Total of 22h30m of classes, October 2018.
2017 Short course “Ingredients for universal quantum computation”, Universidad Autonoma de Mexico (UNAM), approx. 4h30 of classes, October 2017.
2016 Short course “Ingredients for universal quantum computation”, Concepción Summer Physics School – Concepción, Chile, January 2016. Approx. 4h30 of classes.
2015 Short course “Ingredients for universal quantum computation”, V Paraty Quantum Information School (Paraty, August 2015). Approx. 4h30 of classes.
2011 Short course “Introdução à Informação Quântica” at the I Semana da Física do Instituto de Física de São Carlos (USP). 3h30 of classes, 19/10/2011.
2010 Short course “Introdução à Informação Quântica” at the XII Escola de Verão Jorge André Swieca de Ótica Quântica e Ótica Não Linear – 25/1 to 5/2, 2010, IF-UFF.
2004 Monthly columns on science for the ´Sexta Livre´ program of Radio Centre-Ville, Montréal, Canada (in Portuguese).
2003 Keynote speaker at the Young Physicists of Canada program, Perimeter Institute (Canada), August 2003.
2003 Co-organizer of the first Perimeter Institute quantum information workshop (with Ivette Fuentes Guridi). March 25th.
2002 Participation in the 30-minute CKCO-TV (Ontario) program “The big questions“, explaining relativity and quantum theory to school students. First broadcast on Dec 1st, 2002.
2000-Referee for the journals Physical Review A, Physical Review Letters, Quantum Information and Computation, Journal of Physics A, Physics Letters A.
1999-2002 Junior Member of the Isaac Newton Institute for Mathematical Sciences (University of Cambridge).
1999- Various talks at University of Oxford, Cambridge, Federal University of Rio de Janeiro, PUC-Rio, Perimeter Institute, University of Waterloo, Buenos Aires University, Fluminense Federal University, Minas Gerais Federal University, UNICAMP, Brazilian Center for Physical Research (CBPF).
1994-1995 President of the Maths, Chemistry and Physics student society at PUC-Rio.
GROUP LEADER
THE TEAM
Rui Soares Barbosa
Staff Researcher
Leonardo Novo
Staff Researcher
Wagner Balthazar
Research Fellow
Carlos Tavares
Research Fellow
José Nuno Oliveira
Professor at UMinho
Luis Paulo Santos
Professor at UMinho
Luis Soares Barbosa
Professor at Uminho
Renato Neves
Professor at Uminho
Rafael Wagner
PhD student
Anita Camillini
PhD student
Raman Choudhary
PhD student
Angelos Bampounis
PhD student
Antonio Molero
PhD student
Alexandra Ramôa Alves
PhD student
Mafalda Ramôa da Costa
PhD student
José Guimarães
PhD student
André Sequeira
PhD student
Ana Isabel Neri
PhD student
Zeinab Rahmani
PhD student
Manisha Jain
PhD student
Jaime Santos
PhD student
David Ferreira
Associate
Antonio Pereira, David Ferreira, Carlos Tavares, Vitor Fernandes, José Luís Martins (Master’s degree students)
DESCRIPTION
Quantum information science has the potential to revolutionize information processing, in the form of dramatically faster quantum algorithms and novel protocols for cryptography, metrology, and sensing. The Quantum and Linear-Optical Computation group explores the features of quantum theory that enable advantage in quantum information processing tasks, in particular those present in photonic implementations of quantum computers. There is not a single way to harness these quantum effects, so studying different models of quantum computation enables us to pinpoint different ways to get quantum systems to work their magic.
Our group has been recently established, please note the following opportunities:
- If you have a Master’s degree and would like to join as a PhD student, please consider applying to the 2nd round of the Quantum Portugal Initiative PhD scholarships: https://inl.int/quantum-portugal-initiative/
- If you are an experienced researcher in the field, there is a Staff Researcher, tenure-track position open, with application deadline on November 21st, 2019: http://careers.inl.int/our-vacancies/
Multimode interferometers are a special type of photonic quantum computers.
RESEARCH PROJECTS
- Resources for quantum computational speed-up in topological, measurement-based, and circuit-based quantum computation.
- Experimentally-friendly characterization of multi-photon indistinguishability
- Quantum computation with integrated photonic chips
- Classical analogues of quantum non-separability and contextuality
PUBLICATIONS
-
2020
Ernesto F Galvão and Daniel J Brod
Quantum and classical bounds for two-state overlaps Journal Article
Physical Review A, 101 , pp. 062110, 2020, ISSN: 2469-9934.
@article{GalvaoB20,
title = {Quantum and classical bounds for two-state overlaps},
author = {Ernesto F Galvão and Daniel J Brod},
url = {https://doi.org/10.1103/PhysRevA.101.062110},
doi = {10.1103/PhysRevA.101.062110},
issn = {2469-9934},
year = {2020},
date = {2020-06-19},
journal = {Physical Review A},
volume = {101},
pages = {062110},
abstract = {Suppose we have N quantum systems in unknown states |ψi⟩, but we know the value of some pairwise overlaps |⟨ψ_k|ψ_l⟩|^2. What can we say about the values of the unknown overlaps? We provide a complete answer to this problem for three pure states and two given overlaps and a way to obtain bounds for the general case. We discuss how the answer contrasts from that of a classical model featuring only coherence-free, diagonal states, and we describe three applications: basis-independent coherence witnesses, dimension witnesses, and characterization of multiphoton indistinguishability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Suppose we have N quantum systems in unknown states |ψi⟩, but we know the value of some pairwise overlaps |⟨ψ_k|ψ_l⟩|^2. What can we say about the values of the unknown overlaps? We provide a complete answer to this problem for three pure states and two given overlaps and a way to obtain bounds for the general case. We discuss how the answer contrasts from that of a classical model featuring only coherence-free, diagonal states, and we describe three applications: basis-independent coherence witnesses, dimension witnesses, and characterization of multiphoton indistinguishability.Chiara Esposito Niko Viggianiello Marco Romano Fulvio Flamini Gonzalo Carvacho Nicolò Spagnolo Ernesto Galvão F Taira Giordani Daniel J Brod and Fabio Sciarrino
Experimental quantification of four-photon indistinguishability Journal Article
New Journal of Physics, 22 , pp. 043001, 2020, ISSN: 1367-2630.
@article{Giordani20,
title = {Experimental quantification of four-photon indistinguishability},
author = {Chiara Esposito Niko Viggianiello Marco Romano Fulvio Flamini Gonzalo Carvacho Nicolò Spagnolo Ernesto Galvão F Taira Giordani Daniel J Brod and Fabio Sciarrino},
url = {https://iopscience.iop.org/article/10.1088/1367-2630/ab7a30},
doi = {10.1088/1367-2630/ab7a30},
issn = {1367-2630},
year = {2020},
date = {2020-04-02},
journal = {New Journal of Physics},
volume = {22},
pages = {043001},
abstract = {Photon indistinguishability plays a fundamental role in information processing, with applications such as linear-optical quantum computation and metrology. It is then necessary to develop appropriate tools to quantify the amount of this resource in a multiparticle scenario. Here we report a four-photon experiment in a linear-optical interferometer designed to simultaneously estimate the degree of indistinguishability between three pairs of photons. The interferometer design dispenses with the need of heralding for parametric down-conversion sources, resulting in an efficient and reliable optical scheme. We then use a recently proposed theoretical framework to quantify genuine four-photon indistinguishability, as well as to obtain bounds on three unmeasured two-photon overlaps. Our findings are in high agreement with the theory, and represent a new resource-effective technique for the characterization of multiphoton interference.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Photon indistinguishability plays a fundamental role in information processing, with applications such as linear-optical quantum computation and metrology. It is then necessary to develop appropriate tools to quantify the amount of this resource in a multiparticle scenario. Here we report a four-photon experiment in a linear-optical interferometer designed to simultaneously estimate the degree of indistinguishability between three pairs of photons. The interferometer design dispenses with the need of heralding for parametric down-conversion sources, resulting in an efficient and reliable optical scheme. We then use a recently proposed theoretical framework to quantify genuine four-photon indistinguishability, as well as to obtain bounds on three unmeasured two-photon overlaps. Our findings are in high agreement with the theory, and represent a new resource-effective technique for the characterization of multiphoton interference. -
2019
Allan D C Tosta and Daniel J Brod and Ernesto F Galvão.
Quantum computation from fermionic anyons on a 1D lattice Journal Article
Physical Review A, 99 , pp. 062335, 2019.
@article{Tosta2019,
title = {Quantum computation from fermionic anyons on a 1D lattice},
author = {Allan D C Tosta and Daniel J Brod and Ernesto F Galvão.},
url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.99.062335},
doi = {https://doi.org/10.1103/PhysRevA.99.062335},
year = {2019},
date = {2019-07-27},
journal = {Physical Review A},
volume = {99},
pages = {062335},
abstract = {Fermionic linear optics corresponds to the dynamics of free fermions and is known to be efficiently simulable classically. We define fermionic anyon models by deforming the fermionic algebra of creation and annihilation operators, and consider the dynamics of number-preserving, quadratic Hamiltonians on these operators. We show that any such deformation results in an anyonic linear-optical model which allows for universal quantum computation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Fermionic linear optics corresponds to the dynamics of free fermions and is known to be efficiently simulable classically. We define fermionic anyon models by deforming the fermionic algebra of creation and annihilation operators, and consider the dynamics of number-preserving, quadratic Hamiltonians on these operators. We show that any such deformation results in an anyonic linear-optical model which allows for universal quantum computation.D J Brod and E F Galvão and A Crespi and R Osellame and N Spagnolo and F Sciarrino.
Photonic implementation of boson sampling: a review Journal Article
Advanced Photonics, 1 (3), pp. 034001, 2019.
@article{Brod2019,
title = {Photonic implementation of boson sampling: a review},
author = {D J Brod and E F Galvão and A Crespi and R Osellame and N Spagnolo and F Sciarrino.},
doi = {https://doi.org/10.1117/1.AP.1.3.034001},
year = {2019},
date = {2019-06-25},
journal = {Advanced Photonics},
volume = {1},
number = {3},
pages = {034001},
abstract = {Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved by dedicated photonic quantum hardware, comprising single photons, linear evolution, and photodetection. This prospect has stimulated much effort resulting in the experimental implementation of progressively larger devices. We review recent advances in photonic boson sampling, describing both the technological improvements achieved and the future challenges. We also discuss recent proposals and implementations of variants of the original problem, theoretical issues occurring when imperfections are considered, and advances in the development of suitable techniques for validation of boson sampling experiments. We conclude by discussing the future application of photonic boson sampling devices beyond the original theoretical scope.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved by dedicated photonic quantum hardware, comprising single photons, linear evolution, and photodetection. This prospect has stimulated much effort resulting in the experimental implementation of progressively larger devices. We review recent advances in photonic boson sampling, describing both the technological improvements achieved and the future challenges. We also discuss recent proposals and implementations of variants of the original problem, theoretical issues occurring when imperfections are considered, and advances in the development of suitable techniques for validation of boson sampling experiments. We conclude by discussing the future application of photonic boson sampling devices beyond the original theoretical scope.Pinheiro B da Silva and D S Tasca and E F Galvão and A Z Khoury
Astigmatic tomography of orbital-angular-momentum superpositions Journal Article
Physical Review A, 99 , pp. 043820, 2019.
@article{daSilva2019,
title = {Astigmatic tomography of orbital-angular-momentum superpositions},
author = {Pinheiro B da Silva and D S Tasca and E F Galvão and A Z Khoury},
doi = {https://doi.org/10.1103/PhysRevA.99.043820},
year = {2019},
date = {2019-04-16},
journal = {Physical Review A},
volume = {99},
pages = {043820},
abstract = {We use astigmatic transformations to characterize two-dimensional superpositions of orbital-angular-momentum states in laser beams. We propose two methods for doing this, both relying only on astigmatic transformations, viewed as rotations on the Poincaré sphere, followed by imaging. These methods can be used as a tomographic tool for communication protocols based on optical vortices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}We use astigmatic transformations to characterize two-dimensional superpositions of orbital-angular-momentum states in laser beams. We propose two methods for doing this, both relying only on astigmatic transformations, viewed as rotations on the Poincaré sphere, followed by imaging. These methods can be used as a tomographic tool for communication protocols based on optical vortices.D J Brod and E F Galvão and N Viggianiello and F Flamini and N Spagnolo and F Sciarrino
Witnessing genuine multiphoton indistinguishability Journal Article
Physical Review Letters, 122 , pp. 063602, 2019.
@article{Brod2019b,
title = {Witnessing genuine multiphoton indistinguishability},
author = {D J Brod and E F Galvão and N Viggianiello and F Flamini and N Spagnolo and F Sciarrino},
doi = {https://doi.org/10.1103/PhysRevLett.122.063602},
year = {2019},
date = {2019-02-13},
journal = {Physical Review Letters},
volume = {122},
pages = {063602},
abstract = {Bosonic interference is a fundamental physical phenomenon, and it is believed to lie at the heart of quantum computational advantage. It is thus necessary to develop practical tools to witness its presence, both for a reliable assessment of a quantum source and for fundamental investigations. Here we describe how linear interferometers can be used to unambiguously witness genuine
n-boson indistinguishability. The amount of violation of the proposed witnesses bounds the degree of multiboson indistinguishability, for which we also provide a novel intuitive model using set theory. We experimentally implement this test to bound the degree of three-photon indistinguishability in states we prepare using parametric down-conversion. Our approach results in a convenient tool for practical photonic applications, and may inspire further fundamental advances based on the operational framework we adopt.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Bosonic interference is a fundamental physical phenomenon, and it is believed to lie at the heart of quantum computational advantage. It is thus necessary to develop practical tools to witness its presence, both for a reliable assessment of a quantum source and for fundamental investigations. Here we describe how linear interferometers can be used to unambiguously witness genuine
n-boson indistinguishability. The amount of violation of the proposed witnesses bounds the degree of multiboson indistinguishability, for which we also provide a novel intuitive model using set theory. We experimentally implement this test to bound the degree of three-photon indistinguishability in states we prepare using parametric down-conversion. Our approach results in a convenient tool for practical photonic applications, and may inspire further fundamental advances based on the operational framework we adopt. -
2018
N Viggianiello and F Flamini and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino
Optimal photonic indistinguishability tests in multimode networks Journal Article
Science Bulletin, 63 (22), pp. 1470, 2018.
@article{Viggianiello2018,
title = {Optimal photonic indistinguishability tests in multimode networks},
author = {N Viggianiello and F Flamini and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino},
url = {https://www.sciencedirect.com/science/article/pii/S2095927318305061},
doi = {https://doi.org/10.1016/j.scib.2018.10.009},
year = {2018},
date = {2018-11-30},
journal = {Science Bulletin},
volume = {63},
number = {22},
pages = {1470},
abstract = {Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications such as linear optical quantum computation and simulation, in particular for Boson Sampling devices. It is thus crucial to develop tools to certify genuine multiphoton interference between multiple sources. Our approach employs the total variation distance to find those transformations that minimize the error probability in discriminating the behaviors of distinguishable and indistinguishable photons. In particular, we show that so-called Sylvester interferometers are near-optimal for this task. By using Bayesian tests and inference, we numerically show that Sylvester transformations largely outperform most Haar-random unitaries in terms of sample size required. Furthermore, we experimentally demonstrate the efficacy of the transformation using an efficient 3D integrated circuits in the single- and multiple-source cases. We then discuss the extension of this approach to a larger number of photons and modes. These results open the way to the application of Sylvester interferometers for optimal assessment of multiphoton interference experiments.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications such as linear optical quantum computation and simulation, in particular for Boson Sampling devices. It is thus crucial to develop tools to certify genuine multiphoton interference between multiple sources. Our approach employs the total variation distance to find those transformations that minimize the error probability in discriminating the behaviors of distinguishable and indistinguishable photons. In particular, we show that so-called Sylvester interferometers are near-optimal for this task. By using Bayesian tests and inference, we numerically show that Sylvester transformations largely outperform most Haar-random unitaries in terms of sample size required. Furthermore, we experimentally demonstrate the efficacy of the transformation using an efficient 3D integrated circuits in the single- and multiple-source cases. We then discuss the extension of this approach to a larger number of photons and modes. These results open the way to the application of Sylvester interferometers for optimal assessment of multiphoton interference experiments.Neves, and L. S. Barbosa
Languages and models for hybrid automata: A coalgebraic perspective Journal Article
Theoretical Computer Science, Elsevier, 744 , pp. 113-142, 2018.
@article{Neves2018,
title = {Languages and models for hybrid automata: A coalgebraic perspective},
author = {Neves, and L. S. Barbosa},
doi = {10.1016/j.tcs.2017.09.038},
year = {2018},
date = {2018-09-21},
journal = {Theoretical Computer Science, Elsevier},
volume = {744},
pages = {113-142},
abstract = {We study hybrid automata from a coalgebraic point of view. We show that such a perspective supports a generic theory of hybrid automata with a rich palette of definitions and results. This includes, among other things, notions of bisimulation and behaviour, state minimisation techniques, and regular expression languages.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}We study hybrid automata from a coalgebraic point of view. We show that such a perspective supports a generic theory of hybrid automata with a rich palette of definitions and results. This includes, among other things, notions of bisimulation and behaviour, state minimisation techniques, and regular expression languages.N Viggianiello and F Flamini and L Innocenti and D Cozzolino and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino
Experimental generalized quantum suppression law in Sylvester interferometers Journal Article
New Journal of Physics, 20 , pp. 033017, 2018.
@article{Viggianiello2018b,
title = {Experimental generalized quantum suppression law in Sylvester interferometers},
author = {N Viggianiello and F Flamini and L Innocenti and D Cozzolino and M Bentivegna and N Spagnolo and A Crespi and D J Brod and E F Galvão and R Osellame and F Sciarrino},
url = {https://iopscience.iop.org/article/10.1088/1367-2630/aaad92},
doi = {https://doi.org/10.1088/1367-2630/aaad92},
year = {2018},
date = {2018-03-26},
journal = {New Journal of Physics},
volume = {20},
pages = {033017},
abstract = {Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling devices. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong–Ou–Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression occurs for a much larger fraction of input–output combinations than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference, such as quantum simulation and quantum metrology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling devices. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong–Ou–Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression occurs for a much larger fraction of input–output combinations than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference, such as quantum simulation and quantum metrology.
OTHERS
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Preprints
[31] T. giordani, D. J. Brod, C. Esposito, N. Viggianiello, M. Romano, F. Flamini, G. Carvacho, N. Spagnolo, E. F. Galvão, F. Sciarrino. Experimental quantification of genuine four-photon indistinguishability. Arxiv:1907.01325.
[30] E. F. Galvão, D. J. Brod. Quantum and classical bounds for unknown two-state overlaps. ArXiv:1902.11039 [quant-ph].
[29] Galvão E. F. Experimental requirements for quantum communication complexity. Preprint quant-ph/0009014.
[28] E. F. Galvão, Foundations of quantum theory and quantum information applications, D.Phil. (PhD) thesis, University of Oxford, 2002. Preprint arXiv:quant-ph/0212124.
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Scholarships, grants and prizes
2019-2022 CNPq Productivity in Research Grant, level 2.
2016-2019 CNPq Productivity in Research Grant, level 2.
2016 Former PhD student Daniel J. Brod awarded honourific mention at José Leite Lopes Prize for best PhD thesis in physics awarded in 2014 (Brazilian Physics Society).
2011 Teacher Homage recipient at the 2011.1 and 2011.2 graduation ceremonies for the IF-UFF Physics classes.
2011 Co-organizer of the III Quantum Information School and Workshop – Paraty 2011. I was the coordinator of the APQ2/FAPERJ grant (total value: approx. 10000 reais).
2007 Co-organizer of the Paraty07 Quantum Information School/Workshop. I was the coordinator of the CLAF and APQ2/FAPERJ grants (total value: approx. 14000 reais).
2006 FAPERJ grant Programa Primeiros Projetos. Value: R$12500.
2006 CAPES PRODOC post-doctoral scholarship.
2005-2006 CNPq junior postdoctoral scholarship.
2005 Approved in selection process (`concurso´) for assistant professor at IF-UFF.
2004 Approved in selection process (`concurso´) for assistant professor at the UNICAMP Physics Institute. 10 a 12/2/2004.
2002-2005 Postdoctoral Fellowship at the Perimeter Institute for Theoretical Physics.
1999 – 2001 Overseas Research Students (ORS) Award from Universities UK (worth roughly £12000).
1998 – 2002 Ph.D. scholarship for study abroad from the Brazilian agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
1996 – 1998 Master‘s degree scholarship from CAPES.
1995 Tutorship scholarship, PUC-Rio.
1992-1995 Full tuition Academic Performance scholarship, PUC-Rio.
1992-1994 Undergraduate Research Programme scholarship (´Iniciação Científica´) by the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CnPq).
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Teaching and academic supervision
2016- supervision of doctorate student Allan Tosta.
2014-2015 supervision of undergrad student Lucas Lima (undergrad research project).
2013-2015 supervision of students André Oestereich (Master’s degree), and Bárbara Santos and Allan Tosta in undergrad research project.
2009 – 2014 – supervision of doctorate student Daniel Brod.
2008-2013 supervision of doctorate student Raphael Silva.
2008-2009 supervision of postdoc Rômulo Abreu.
2005- Undergraduate teaching: Basic Physics II and III; Quantum Mechanics I and II; Classical Mechanics I; Electromagnetism I and II, Experimental Physics Laboratory II. Graduate teaching: Quantum Information and Quantum Computation I, Quantum Mechanics I.
2003-2004 Co-supervision of undergraduate research project of student Aissa Stein, University of Waterloo (jointly with Lee Smolin).
2002 Co-supervised award-winning summer project of student Hilary Greaves at Clarendon Laboratory, Oxford (with Lucien Hardy).
2000, 2001 Tutor in two one-week long physics courses for gifted A-level (secondary) students. Villiers Park Educational Trust (United Kingdom).
1995 Volunteer tutor for poor students aiming at passing the university entrance exam. André Maurois school, Rio de Janeiro.
1995 Tutor in “Physics for Arts” course at PUC-Rio.
1995 Tutor in exercise classes for basic physics course (Physics II), PUC-Rio.
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Conferences and workshops
2018 XXXVIII Congresso Nacional de Matemática Aplicada e Computacional (CNMAC), invited talk “Quantum and classical equality testing” in Mini-symposium “Mathematics of Quantum Mechanics”. (September 17-21).
2017 Workshop “Quantum correlations, contextuality and all that, again and again”, International Institute of Physics, Natal. Invited talk: “Reliable computation from contextual correlations” (Nov. 20-24).
2016 XXXIX Encontro Nacional de Física da Matéria Condensada. Invited talk: Quantum computation with photonic chips.
2015 Workshop PICQUE Roma Scientific School 2015. Invited talk: Boson Sampling – a bit of theory.
2015 Workshop “Quantum Correlations, Contextuality, and All That Again”, International Institute of Physics, Natal. Invited talk: “Computing with contextual correlations”.
2015 V Paraty Quantum Information Workshop. Invited talk: Boson sampling in photonic chips.
2015 XXXVIII Encontro Nacional de Física da Matéria Condensada. Invited talk: Boson Sampling in integrated photonic chips.
2015 V Workshop em Comunicação e Informação Quântica (Campina Grande, Paraíba, Brazil, March). Invited talk: Boson sampling in photonic chips.
2014 Meeting: O Pote de Ouro de Bell – 50 anos das desigualdades de Bell. Invited talk: Não-localidade além da mecânica quântica.
2014 Talk “Boson Sampling in photonic chips” at the conferece Quantum Optics VII – Mar del Plata, Argentina (October).
2014 Invited talk at 1-day symposium “O Pote de Ouro de Bell – 50 anos das desigualdades de Bell”, CBPF, 5/12/2014.
2013 Seminário convidado no workshop “Quantum information seen through closed timelike curves”, Fondation des Treilles, França (junho).
2013 Invited talk at the “Quantum information seen through closed timelike curves” workhop in France, Fondation des Treilles (June).
2013 Invited talk at the Quantum Information Workshop – Paraty 2013 (Paraty, Brazil, August).
2011 Poster at Quantum Information Processing Workshop – QIP2012, Montréal, Canada, December.
2011 Talk at the 5th Feynman Festival (May), Foz do Iguaçu, Brazil.
2010 Talk at the Workshop on Quantum Algorithms, Computational Models and Foundations of Quantum Mechanics (QAMF), Vancouver, Canada, 23-25/7/2010.
2010 Poster presentation at Quantum Information Processing Workshop (QIP) 2010, Zurich, Switzerland.
2009 Invited speaker at the XV Escola Regional de Informática – Paraná, with talks in Curitiba and Bandeirantes.
2009 Invited speaker at SEMISH 2009, part of the XXIX Congresso da Sociedade Brasileira de Computação.
2009 Talk at Paraty09 – Quantum Information Workshop.
2008 Poster presentation at Quantum Optics IV – Florianópolis.
2006 Talk at the Young Researchers Symposium of the International Congress on Mathematical Physics – ICMP 2006. IMPA, Rio de Janeiro, 04/08 to 11/08.
2006 Talk at the Workshop on Theory and Technology in Quantum Information, Communication, Computation and Cryptography, Trieste, 19-23rd June.
2005 Talk at the Quantum Physics of Nature & 6th European QIPC Workshop, Vienna. May 22nd-26th.
2004 Quantum Information Theory: Present Status and Future Directions workshop, Isaac Newton Institute, Cambridge (U.K.), 23-27 August.
2004 Quantum computing, Quantum Information, Quantum Gravity workshop, Perimeter Institute, Waterloo (Canada), February 23-27th.
2004 QIP 2004 – The Seventh Workshop on Quantum Information Processing. Waterloo, Canada, January 15-19th.
2003 Pan American Advanced Studies Institute on the Physics of Information, Búzios, Brazil, December 4-9th.
2003 Quantum Information and Communication workshop in the Benasque Center for Science, Spain, June 22 – July 13.
2002 Talk at the IUPAP International Conference on “Quantum Entanglement, Complexity and the Physical Basis for Quantum Computation“, CBPF, Rio de Janeiro, Brazil, December 2-6.
2002 Poster presentation at the EURESCO Conference on quantum information: quantum entanglement. San Feliu de Guixols, Spain, March 23-28.
2002 Poster presentation at the International Conference on Quantum information: conceptual foundations. University of Oviedo, Spain, July 13-18.
2002 Poster presentation at QRANDOM II Conference at the Max Planck Institute- Dresden (27/01 to 02/02).
2001 Talk in open session of Fourth Workshop on Quantum Information Processing. CWI, Amsterdam, January 9-12.
2000 Poster presentation at Fifth International Conference on Quantum Communication, Measurement & Computing. Capri, Italy, July 3-8.
1999 8th U.K. Foundations of Physics meeting. 13/9 to 17/9/1999.
1999 Newton Institute workshop on Complexity, Computation and the Physics of Information (Cambridge). 5/7 to 17/7/99.
1998 Jorge André Swieca Summer School on Quantum and non-linear Optics (São Carlos, Brazil). 05/01/1998 to 16/01/1998.
1996,1997 Two summer courses at the Mathematics Department, PUC-Rio, on Information Theory and Discrete Mathematics. 12/02/96 to 16/02/96, 17/02/97 to 28/02/97.
1993,1995 Lafex International Schools on High Energy Physics (LISHEP‘93 and LISHEP‘95), organized by LAFEX – CBPF. 24/01/93 to 13/02/93 and 06/02/95 to 22/02/95.
1992-1994 Pursued an undergraduate research project in the High-Energy Physics and Cosmology Laboratory of the Brazilian Centre for Physical Research (LAFEX- CBPF).
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Other Activities
2019 Participation in the examination committee (president) to select an adjoint professor at the Physics Institute of Universidade de São Paulo (USP).
2019 Program committee of The 14th Conference on the Theory of Quantum Computation, Communication, and Cryptography – TQC 2019.
2018 Short course “Introduction to quantum computation and simulability” at ICTP-SAIFR/IFT-UNESP (São Paulo), jointly with Daniel Brod and Leandro Aolita. Total of 22h30m of classes, October 2018.
2017 Short course “Ingredients for universal quantum computation”, Universidad Autonoma de Mexico (UNAM), approx. 4h30 of classes, October 2017.
2016 Short course “Ingredients for universal quantum computation”, Concepción Summer Physics School – Concepción, Chile, January 2016. Approx. 4h30 of classes.
2015 Short course “Ingredients for universal quantum computation”, V Paraty Quantum Information School (Paraty, August 2015). Approx. 4h30 of classes.
2011 Short course “Introdução à Informação Quântica” at the I Semana da Física do Instituto de Física de São Carlos (USP). 3h30 of classes, 19/10/2011.
2010 Short course “Introdução à Informação Quântica” at the XII Escola de Verão Jorge André Swieca de Ótica Quântica e Ótica Não Linear – 25/1 to 5/2, 2010, IF-UFF.
2004 Monthly columns on science for the ´Sexta Livre´ program of Radio Centre-Ville, Montréal, Canada (in Portuguese).
2003 Keynote speaker at the Young Physicists of Canada program, Perimeter Institute (Canada), August 2003.
2003 Co-organizer of the first Perimeter Institute quantum information workshop (with Ivette Fuentes Guridi). March 25th.
2002 Participation in the 30-minute CKCO-TV (Ontario) program “The big questions“, explaining relativity and quantum theory to school students. First broadcast on Dec 1st, 2002.
2000-Referee for the journals Physical Review A, Physical Review Letters, Quantum Information and Computation, Journal of Physics A, Physics Letters A.
1999-2002 Junior Member of the Isaac Newton Institute for Mathematical Sciences (University of Cambridge).
1999- Various talks at University of Oxford, Cambridge, Federal University of Rio de Janeiro, PUC-Rio, Perimeter Institute, University of Waterloo, Buenos Aires University, Fluminense Federal University, Minas Gerais Federal University, UNICAMP, Brazilian Center for Physical Research (CBPF).
1994-1995 President of the Maths, Chemistry and Physics student society at PUC-Rio.