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Sobre

Sobre

Sou Professor Catedrático no Departamento de Informática da Universidade do Minho, e investigador sénior no High Assurance Software Laboratory (HASLab INESC TEC). Desde Outubro de 2016, sou Director Adunto da UNU-EGOV, a Operational Unit on Policy-driven Electronic Governance da Universidade das Nações Unidas (egov.unu.edu).

Os meus interesses de investigação estão focados na semântica do fenómeno computacional e no desenvolvimento de cálculos de programs aplicados à compreensão de sistemas e à concepção de software. Estou particularmente interessado em teoria das coálgebras e raciocínio coindutivo, assim como em lógicas modais e híbridas.

Nos últimos anos coordenei quatro projectos de investigação a nível nacional, parcerias bilaterais com o Brasil e China, e fui coordenador no lado português de uma rede ALFA (Europa - América Latina) para formação doutoral. Sou autor de cinco capítulos de livro,  25 artigos em revistas indexadas, e mais de 60 artigos em conferências internacionais. Tendo lecionado em curso de Mestrado e Programas Doutorais nas Universidades de Bristol (Reino Unido), Tartu (Estónia), e Pequim (China), orientei igualmente diversos projectos de doutoramento (seis concluídos; quatro em curso). Um dos meus orientando,  Alexandre Madeira, recebeu o Prémio Científico IBM para 2013, o mais importante prémio científico em Informática em Portugal.

Integrei, por nomeação reitoral,  o grupo que concebeu e implementou o "Joint Doctoral Programme in Computer Science of the Universities of Minho, Aveiro, and Porto" (MAP-i), tendo mais tarde servido como seu director. Sou membro do IFIP WG1.3 (Foundations of System Specification), e, desde Janeiro 2019, coordenador do IFIP Tecnhical Committee TC1 on Foundations of Computer Science.

Actualmente coordeno o Quantum Software Engineering Research Group no INL, o International Iberian Nanotechnology Laboratoryf.

Tópicos
de interesse
Detalhes

Detalhes

  • Nome

    Luís Soares Barbosa
  • Cargo

    Investigador Coordenador
  • Desde

    01 novembro 2011
  • Nacionalidade

    Portugal
  • Contactos

    +351253604440
    luis.s.barbosa@inesctec.pt
003
Publicações

2024

On Quantum Natural Policy Gradients

Autores
Sequeira, A; Santos, LP; Barbosa, LS;

Publicação
CoRR

Abstract

2024

Digital quantum simulation of non-perturbative dynamics of open systems with orthogonal polynomials

Autores
Guimaraes, JD; Vasilevskiy, MI; Barbosa, LS;

Publicação
QUANTUM

Abstract
Classical non-perturbative simulations of open quantum systems' dynamics face several scalability problems, namely, exponential scaling of the computational effort as a function of either the time length of the simulation or the size of the open system. In this work, we propose the use of the Time Evolving Density operator with Orthogonal Polynomials Algorithm (TEDOPA) on a quantum computer, which we term as Quantum TEDOPA (Q-TEDOPA), to simulate nonperturbative dynamics of open quantum systems linearly coupled to a bosonic environment (continuous phonon bath). By performing a change of basis of the Hamiltonian, the TEDOPA yields a chain of harmonic oscillators with only local nearestneighbour interactions, making this algorithm suitable for implementation on quantum devices with limited qubit connectivity such as superconducting quantum processors. We analyse in detail the implementation of the TEDOPA on a quantum device and show that exponential scalings of computational resources can potentially be avoided for time-evolution simulations of the systems considered in this work. We applied the proposed method to the simulation of the exciton transport between two light-harvesting molecules in the regime of moderate coupling strength to a non-Markovian harmonic oscillator environment on an IBMQ device. Applications of the Q-TEDOPA span problems which can not be solved by perturbation techniques belonging to different areas, such as the dynamics of quantum biological systems and strongly correlated condensed matter systems.

2024

Secure two-party computation via measurement-based quantum computing

Autores
Rahmani, Z; Pinto, AHMN; Barbosa, LMDCS;

Publicação
QUANTUM INFORMATION PROCESSING

Abstract
Secure multiparty computation (SMC) provides collaboration among multiple parties, ensuring the confidentiality of their private information. However, classical SMC implementations encounter significant security and efficiency challenges. Resorting to the entangled Greenberger-Horne-Zeilinger (GHZ) state, we propose a quantum-based two-party protocol to compute binary Boolean functions, with the help of a third party. We exploit a technique in which a random Z-phase rotation on the GHZ state is performed to achieve higher security. The security and complexity analyses demonstrate the feasibility and improved security of our scheme compared to other SMC Boolean function computation methods. Additionally, we implemented the proposed protocol on the IBM QisKit and found consistent outcomes that validate the protocol's correctness.

2023

Paraconsistent Transition Systems

Autores
Cruz, A; Madeira, A; Barbosa, LS;

Publicação
ELECTRONIC PROCEEDINGS IN THEORETICAL COMPUTER SCIENCE

Abstract
Often in Software Engineering a modelling formalism has to support scenarios of inconsistency in which several requirements either reinforce or contradict each other. Paraconsistent transition systems are proposed in this paper as one such formalism: states evolve through two accessibility relations capturing weighted evidence of a transition or its absence, respectively. Their weights come from a specific residuated lattice. A category of these systems, and the corresponding algebra, is defined providing a formal setting to model different application scenarios. One of them, dealing with the effect of quantum decoherence in quantum programs, is used for illustration purposes.

2023

Policy gradients using variational quantum circuits

Autores
Sequeira, A; Santos, LP; Barbosa, LS;

Publicação
QUANTUM MACHINE INTELLIGENCE

Abstract
Variational quantum circuits are being used as versatile quantum machine learning models. Some empirical results exhibit an advantage in supervised and generative learning tasks. However, when applied to reinforcement learning, less is known. In this work, we considered a variational quantum circuit composed of a low-depth hardware-efficient ansatz as the parameterized policy of a reinforcement learning agent. We show that an epsilon-approximation of the policy gradient can be obtained using a logarithmic number of samples concerning the total number of parameters. We empirically verify that such quantum models behave similarly to typical classical neural networks used in standard benchmarking environments and quantum control, using only a fraction of the parameters. Moreover, we study the barren plateau phenomenon in quantum policy gradients using the Fisher information matrix spectrum.

Teses
supervisionadas

2023

Timing Constraints in Quantum Programming Languages

Autor
Vítor Emanuel Gonçalves Fernandes

Instituição
UM

2023

Time-structure in measurement-based quantum computation

Autor
Michael de Oliveira

Instituição
UM

2023

Continuous-time Quantum Walks

Autor
Jaime Pereira Santos

Instituição
UM

2022

Timing Constraints in Quantum Programming Languages

Autor
Vítor Emanuel Gonçalves Fernandes

Instituição
UM

2022

Continuous-time Quantum Walks

Autor
Jaime Pereira Santos

Instituição
UM