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:
- 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.
- Photonic quantum computation
- Requirements for scalable photonic quantum computation;
- Characterization of multiphoton indistinguishability;
- Computational uses for complex, reconfigurable multi-mode interferometers;
- Classical simulation algorithms.
- 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.
Projects
Publications
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Lifting noncontextuality inequalities
R Choudhary, RS Barbosa, A Cabello
Physical Review A 109, 052216, 2024Inequalities witnessing coherence, nonlocality, and contextuality
R Wagner, RS Barbosa, EF Galvão
Physical Review A 109, 032220, 2024Combining contextuality and causality: a game semantics approach
S Abramsky, RS Barbosa, A Searle
Philosophical Transactions of the Royal Society A 382, 20230002, 2024Measuring relational information between quantum states, and applications
M Oszmaniec, DJ Brod, EF Galvão
New Journal of Physics 26, 013053, 2024Non-stabilizerness and entanglement from cat-state injection
FCR Peres, R Wagner, EF Galvão
New Journal of Physics 26, 013051, 2024Quantum circuits for measuring weak values, Kirkwood–Dirac quasiprobability distributions, and state spectra
R Wagner, Z Schwartzman-Nowik, IL Paiva, A Te'eni, A Ruiz-Molero, RS Barbosa, E Cohen, EF Galvão
Quantum Science and Technology 9, 015030, 2024Coherence and contextuality in a Mach-Zehnder interferometer
R Wagner, A Camillini, EF Galvão
Quantum 8, 1240., 2024Quantum advantage in temporally flat measurement-based quantum computation
M Oliveira, LS Barbosa, EF Galvão
Quantum 8, 1312, 2024 -
Quantum circuit compilation and hybrid computation using Pauli-based computation
QUANTUM, 2023Non-separability classification of degrees of freedom of light assisted by machine learning
OPTICS COMMUNICATIONS, 2023Quantum circuits to measure scalar spin chirality
L. I. Reascos, Bruno Murta, E. F. Galvão, and J. Fernández-Rossier. Phys. Rev. Research 5, 043087 (2023), 2023Simple proof that anomalous weak values require coherence
Rafael Wagner and Ernesto F. Galvão, Phys. Rev. A 108, L040202 (2023), 2023Experimental certification of contextuality, coherence, and dimension in a programmable universal photonic processor
T Giordani et al.
Science Advances 9, eadj4249, 2023Machine learning classification of speckle patterns for roughness measurements
Physics Letters A, 128736 (2023)., 2023Boson bunching is not maximized by indistinguishable particles
NATURE PHOTONICS, 2023Non-linear Boson Sampling
NPJ QUANTUM INFORMATION, 2023Partial nonseparability of spin-orbit modes
JOURNAL OF OPTICS, 2023Sheaf representation of monoidal categories
RS Barbosa, C Heunen
Advances in Mathematics 416, 108900, 2023Closing Bell: Boxing black box simulations in the resource theory of contextuality
RS Barbosa, M Karvonen, S Mansfield
Chapter in "Samson Abramsky on Logic and Structure in Computer Science and Beyond", A. Palmigiano, M. Sadrzadeh (eds), vol. 25 of Outstanding Contributions to Logic. Springer., 2023 -
Quadratic Speedup for Spatial Search by Continuous-Time Quantum Walk
PHYSICAL REVIEW LETTERS, 2022Continuous-variable nonlocality and contextuality
RS Barbosa, T Douce, P-E Emeriau, E Kashefi, S Mansfield
Communications in Mathematical Physics 391, 1047–1089, 2022Spin-orbit maximally discordant mixed states
PHYSICAL REVIEW A, 2022 -
The logic of contextuality
S Abramsky, RS Barbosa
29th EACSL Annual Conference on Computer Science Logic (CSL 2021), Leibniz International Proceedings in Informatics (LIPIcs) 183: 5:1–5:18, 2021Witnesses of coherence and dimension from multiphoton indistinguishability tests
PHYSICAL REVIEW RESEARCH, 2021Gaussian optical networks for one-dimensional anyons
PHYSICAL REVIEW A, 2021 -
Quantum and classical bounds for two-state overlaps
PHYSICAL REVIEW A, 2020Experimental quantification of four-photon indistinguishability
NEW JOURNAL OF PHYSICS, 2020