Preprints

    1 a 15 de 64 Preprints encontradas

  • Quantum communication complexity beyond Bell nonlocality
    Joseph Ho, George Moreno, Samuraí Brito, Francesco Graffitti, Christopher L. Morrison, Ranieri Nery, Alexander Pickston, Massimiliano Proietti, Rafael Rabelo, Alessandro Fedrizzi, Rafael Chaves
  • Statistical Properties of the Quantum Internet
    Samuraí Brito, Askery Canabarro, Rafael Chaves, Daniel Cavalcanti
  • Weyl–Wigner representation of canonical equilibrium states
    F Nicacio

    The Weyl-Wigner representations for canonical thermal equilibrium quantum states are obtained for the whole class of quadratic Hamiltonians through a Wick rotation of the Weyl-Wigner symbols of Heisenberg and metaplectic operators. The behavior of classical structures inherently associated to these unitaries is described under the Wick mapping, unveiling that a thermal equilibrium state is fully determined by a complex symplectic matrix, which sets all of its thermodynamical properties. The four categories of Hamiltonian dynamics (Parabolic, Elliptic, Hyperbolic, and Loxodromic) are analyzed. Semiclassical and high temperature approximations are derived and compared to the classical and/or quadratic behavior.

  • Causal Networks and Freedom of Choice in Bell’s Theorem
    Rafael Chaves, George Moreno, Emanuele Polino, Davide Poderini, Iris Agresti, Alessia Suprano, Mariana R. Barros, Gonzalo Carvacho, Elie Wolfe, Askery Canabarro, Robert W. Spekkens, Fabio Sciarrino
  • Device-independent secret sharing and a stronger form of Bell nonlocality
    M. G. M. Moreno, Samuraí Brito, Ranieri V. Nery, Rafael Chaves
  • General Method for Classicality Certification in the Prepare and Measure Scenario
    Carlos de Gois, George Moreno, Ranieri Nery, Samuraí Brito, Rafael Chaves, Rafael Rabelo
  • Bell nonlocality using tensor networks and sparse recovery
    I. S. Eliëns, S. G. A. Brito, R. Chaves
  • Williamson theorem in classical, quantum, and statistical physics
    F. Nicacio

    The objective of this text is to present (and encourage the use of) the Williamson theorem and its consequences in several contexts in physics. The demonstration of the theorem is performed using only basic concepts of linear algebra and symplectic matrices. The immediate application is to place the study of small oscillations in the Hamiltonian scenario, where the theorem shows itself as a useful and practical tool for revealing the normal-mode coordinates and frequencies of the system. A modest introduction of the symplectic formalism in quantum mechanics is presented, which consequently opens up the use of the theorem to study quantum normal modes and quantum small oscillations, allowing the theorem to be applied to the canonical distribution of thermodynamically stable systems described by quadratic Hamiltonians. As a last example, a more advanced topic concerning uncertainty relations is developed to show once more its utility in a distinct and modern perspective.

  • Semi-device-independent certification of entanglement in superdense coding
    George Moreno, Ranieri Nery, Carlos de Gois, Rafael Rabelo, Rafael Chaves
  • Monogamy of temporal correlations: Witnessing non-Markovianity beyond data processing
    Matheus Capela, Lucas C. Céleri, Kavan Modi, Rafael Chaves
  • Approximating Invertible Maps by Recovery Channels: Optimality and an Application to Non-Markovian Dynamics
    Lea Lautenbacher, Fernando de Melo, Nadja K. Bernardes
  • Satellite-Based Photonic Quantum Networks Are Small-World
    Samuraí Brito, Askery Canabarro, Daniel Cavalcanti, Rafael Chaves
  • Minkowski structure for purity and entanglement of Gaussian bipartite states
    Marcos C. de Oliveira, Fernando Nicacio, Salomon S. Mizrahi
  • Causal inference with imperfect instrumental variables
    Nikolai Miklin, Mariami Gachechiladze, George Moreno, Rafael Chaves
  • Quantifying Causal Influences in the Presence of a Quantum Common Cause
    Mariami Gachechiladze, Nikolai Miklin, Rafael Chaves