Recent Submissions

  • Correlation constraints and the Bloch geometry of two qubits 

    Morelli, S.Autoridad BCAM; Eltschka, C.; Huber, M.; Siewert, J. (2024-01-19)
    We present an inequality on the purity of a bipartite state depending solely on the length difference of the local Bloch vectors. For two qubits this inequality is tight for all marginal states and so extends the previously ...
  • Resource-Efficient High-Dimensional Entanglement Detection via Symmetric Projections 

    Morelli, S.Autoridad BCAM; Huber, M.; Tavakoli, A. (2023-10-25)
    We introduce two families of criteria for detecting and quantifying the entanglement of a bipartite quantum state of arbitrary local dimension. The first is based on measurements in mutually unbiased bases and the second ...
  • Coplanar Antenna Design for Microwave Entangled Signals Propagating in Open Air 

    Gonzalez-Raya, T.; Sanz, M.Autoridad BCAM (2022-01-01)
    Open-air microwave quantum communication and metrology protocols must be able to transfer quantum resources from a cryostat, where they are created, to an environment dominated by thermal noise. Indeed, the states carrying ...
  • Quantum-enhanced Doppler lidar 

    Reichert, M.; Di Candia, R.; Win, M.Z.; Sanz, M.Autoridad BCAM (2022-12-01)
    We propose a quantum-enhanced lidar system to estimate a target’s radial velocity, which employs squeezed and frequency-entangled signal and idler beams. We compare its performance against a classical protocol using a ...
  • Bi-Frequency Illumination: A Quantum-Enhanced Protocol 

    Casariego, M.; Omar, Y.; Sanz, M.Autoridad BCAM (2022-11-01)
    Quantum-enhanced, idler-free sensing protocol to measure the response of a target object to the frequency of a probe in a noisy and lossy scenario is proposed. In this protocol, a target with frequency-dependent reflectivity ...
  • Approximating the quantum approximate optimization algorithm with digital-analog interactions 

    Headley, D.; Müller, T.; Martin, A.; Solano, E.; Sanz, M.Autoridad BCAM; Wilhelm, F.K. (2022-10-01)
    The quantum approximate optimization algorithm was proposed as a heuristic method for solving combinatorial optimization problems on near-term quantum computers and may be among the first algorithms to perform useful ...
  • Hybrid quantum-classical heuristic for the bin packing problem 

    De Andoin, M.G.; Sanz, M.Autoridad BCAM; Osaba, E.; Oregi, I.; Villar-Rodriguez, E. (2022-07-09)
    Optimization problems is one of the most challenging applications of quantum computers, as well as one of the most relevants. As a consequence, it has attracted huge efforts to obtain a speedup over classical algorithms ...
  • Open-Air Microwave Entanglement Distribution for Quantum Teleportation 

    Gonzalez-Raya, T.; Casariego, M.; Fesquet, F.; Renger, M.; Salari, V.; Möttönen, M.; Omar, Y.; Deppe, F.; Fedorov, K. G.; Sanz, M.Autoridad BCAM (2022-10-01)
    Microwave technology plays a central role in current wireless communications, including mobile communication and local area networks. The microwave range shows relevant advantages with respect to other frequencies in ...
  • A b-symplectic slice theorem 

    Braddell, R.; Kiesenhofer, A.; Miranda, E. (2022-01-01)
    In this article, motivated by the study of symplectic structures on manifolds with boundary and the systematic study of b -symplectic manifolds started in Guillemin, Miranda, and Pires Adv. Math. 264 (2014), 864–896, we ...
  • Classical dynamics from self-consistency equations in quantum mechanics 

    Bru, J.-B.Autoridad BCAM; de Siqueira Pedra, W.Autoridad BCAM (2022-05-09)
    During the last three decades, P. Bóna has developed a non-linear generalization of quantum mechanics, based on symplectic structures for normal states and offering a general setting which is convenient to study the emergence ...
  • Time Dynamics in Quantum Field Theory Systems 

    LIll, S. (2022-12-23)
    In this doctoral thesis, we develop and investigate new mathematical tools that are intended to allow for a rigorous description of non–perturbative quantum field theory (QFT) dynamics. Here, the term QFT is to be understood ...
  • Implementing Bogoliubov Transformations Beyond the Shale-Stinespring Condition 

    LIll, S. (2022-04-28)
    We provide two extensions of a dense subspace of Fock space, such that Bogoliubov transformations become implementable on them, even though they violate the Shale-Stinespring condition, so they are not implementable on ...
  • Extended State Space for Describing Renormalized Fock Spaces in QFT 

    LIll, S. (2022-06-04)
    In quantum field theory (QFT) models, it often seems natural to use, instead of wave functions from Fock space, wave functions that are not square-integrable and have prefactors involving divergent integrals (known as ...
  • Entanglement of classical and quantum short-range dynamics in mean-field systems 

    Bru, J. B.; de Siqueira Pedra, W.Autoridad BCAM (2021-11-01)
    The relationship between classical and quantum mechanics is usually understood via the limit ħ→0. This is the underlying idea behind the quantization of classical objects. The apparent incompatibility of general relativity ...
  • High temperature convergence of the KMS boundary conditions: The Bose-Hubbard model on a finite graph 

    Zied, A.; Ratsimanetrimanana, A. (2021-08-01)
    The Kubo-Martin-Schwinger (KMS) condition is a widely studied fundamental property in quantum statistical mechanics which characterizes the thermal equilibrium states of quantum systems. In the seventies, Gallavotti and ...
  • Another Proof of Born's Rule on Arbitrary Cauchy Surfaces 

    LIll, S.; Tumulka, R. (2021-10-14)
    In 2017, Lienert and Tumulka proved Born's rule on arbitrary Cauchy surfaces in Minkowski space-time assuming Born's rule and a corresponding collapse rule on horizontal surfaces relative to a fixed Lorentz frame, as well ...
  • Macroscopic Dynamics of the Strong-Coupling BCS-Hubbard Model 

    Bru, J.-B.Autoridad BCAM; de Siqueira Pedra, W.Autoridad BCAM (2020)
    The aim of the current paper is to illustrate, in a simple example, our recent, very general, rigorous results on the dynamical properties of fermions and quantum-spin systems with long-range, or mean-field, interactions, ...
  • Quantum Fluctuations and Large Deviation Principle for Microscopic Currents of Free Fermions in Disordered Media 

    Bru, J.-B.Autoridad BCAM; de Siqueira Pedra, W.Autoridad BCAM; Ratsimanetrimanana, A. (2020)
    We contribute an extension of large-deviation results obtained in [N.J.B. Aza, J.-B. Bru, W. de Siqueira Pedra, A. Ratsimanetrimanana, J. Math. Pures Appl. 125 (2019) 209] on conductivity theory at atomic scale of free ...
  • Weak* Hypertopologies with Application to Genericity of Convex Sets 

    Bru, J.-B.Autoridad BCAM; de Siqueira Pedra, W.Autoridad BCAM (2022)
    We propose a new class of hypertopologies, called here weak$^{\ast }$ hypertopologies, on the dual space $\mathcal{X}^{\ast }$ of a real or complex topological vector space $\mathcal{X}$. The most well-studied and well-known ...
  • Large Deviations in Weakly Interacting Fermions - Generating Functions as Gaussian Berezin Integrals and Bounds on Large Pfaffians 

    Aza, N. J. B.; Bru, J.-B.Autoridad BCAM; de Siqueira Pedra, W.Autoridad BCAM; Müssnich, L. C. P. A. M. (2021)
    We prove that the G\"{a}rtner--Ellis generating function of probability distributions associated with KMS states of weakly interacting fermions on the lattice can be written as the limit of logarithms of Gaussian Berezin ...

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