Browsing by Author "Bru, J.B."
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ACConductivity Measure from Heat Production of Free Fermions in Disordered Media
Bru, J.B.; de Siqueira Pedra, W.; Hertling, C. (20151231)We extend (Bru et al. in J Math Phys 56:051901151, 2015) in order to study the linear response of free fermions on the lattice within a (independently and identically distributed) random potential to a macroscopic electric ... 
Accuracy of Classical Conductivity Theory at Atomic Scales for Free Fermions in Disordered Media
Aza, N.J.B.; Bru, J.B.; de Siqueira Pedra, W.; Ratsimanetrimanana, A. (20190122)The growing need for smaller electronic components has recently sparked the interest in the breakdown of the classical conductivity theory near the atomic scale, at which quantum effects should dominate. In 2012, experimental ... 
Characterization of the QuasiStationary State of an Impurity Driven by Monochromatic Light II: Microscopic Foundations
Bru, J.B.; de Siqueira Pedra, W. (20151231)From quantum mechanical first principles only, we rigorously study the timeevolution of a Nlevel atom (impurity) interacting with an external monochromatic light source within an infinite system of free electrons at ... 
Classical dynamics generated by longrange interactions for lattice fermions and quantum spins
Bru, J.B.; de Siqueira Pedra, W. (2021)We study the macroscopic dynamical properties of fermion and quantumspin systems with longrange, or meanfield, interactions. The results obtained are far beyond previous ones and require the development of a mathematical ... 
DWave pairing driven by bipolaric modes related to giant electronphonon anomalies in highTc superconductors
Bru, J.B.; de Pasquale, A.D.; de Siqueira Pedra, W. (20151231)Taking into account microscopic properties of most usual highTc superconductors, like cuprates, we define a class of microscopic model Hamiltonians for two fermions (electrons or holes) and one boson (bipolaron) on the ... 
Decay of Complextime Determinantal and Pfaffian\ Correlation Functionals in Lattices
Aza, N.J.B.; Bru, J.B.; de Siqueira Pedra, W. (20180124)We supplement the determinantal and Pfaffian bounds of Sims and Warzel (Commun Math Phys 347:903931, 2016) for manybody localization of quasifree fermions, by considering the high dimensional case and complextime ... 
Diagonalizing quadratic bosonic operators by nonautonomous flow equations volker bach
Bach, V.; Bru, J.B. (20160101)We study a nonautonomous, nonlinear evolution equation on the space of operators on a complex Hilbert space. We specify assumptions that ensure the global existence of its solutions and allow us to derive its asymptotics ... 
The Discretenessdriven Relaxation of Collisionless Gravitating Systems: Entropy Evolution in External Potentials, Ndependence, and the Role of Chaos
Beraldo e Silva, L.; de Siqueira Pedra, W.; Valluri, M.; Sodré, L.; Bru, J.B. (20190110)We investigate the old problem of the fast relaxation of collisionless Nbody systems that are collapsing or perturbed, emphasizing the importance of (noncollisional) discreteness effects. We integrate orbit ensembles in ... 
From the 2nd Law of Thermodynamics to AC–Conductivity Measures of Interacting Fermions in Disordered Media
Bru, J.B.; de Siqueira Pedra, W. (20150520)We study the dynamics of interacting lattice fermions with random hopping amplitudes and random static potentials, in presence of timedependent electromagnetic fields. The interparticle interaction is shortrange and ... 
Heat production of noninteracting fermions subjected to electric fields
Bru, J.B.; de Siqueira Pedra, W.; Hertling, C. (20140721)Electric resistance in conducting media is related to heat (or entropy) production in the presence of electric fields. In this paper, by using Araki's relative entropy for states, we mathematically define and analyze the ... 
Isotropic BipolaronFermionExchange Theory and Unconventional Pairing in Cuprate Superconductors
Bru, J.B.; de Siqueira Pedra, W.; de Pasquale, A.D. (20170503)The discovery of hightemperature superconductors in 1986 represented a major experimental breakthrough (Nobel Prize 1987), but their theoretical explanation is still a subject of much debate. These materials have many ... 
Isotropic BipolaronFermionExchange Theory and Unconventional Pairing in Cuprate Superconductors
Bru, J.B.; de Siqueira Pedra, W.; Delgado de Pasquale, A. (20181210)The discovery of hightemperature superconductors in 1986 represented a major experimental breakthrough (Nobel Prize 1987), but their theoretical explanation is still a subject of much debate. These materials have many ... 
Large Deviations in Weakly Interacting Fermions  Generating Functions as Gaussian Berezin Integrals and Bounds on Large Pfaffians
Aza, N. J. B.; Bru, J.B.; de Siqueira Pedra, W.; Müssnich, L. C. P. A. M. (2021)We prove that the G\"{a}rtnerEllis 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 ... 
Lieb–Robinson Bounds for Multi–Commutators and Applications to Response Theory
Bru, J.B.; de Siqueira Pedra, W. (20160101)We generalize to multi–commutators the usual Lieb–Robinson bounds for commutators. In the spirit of constructive QFT, this is done so as to allow the use of combinatorics of minimally connected graphs (tree expan sions) ... 
Lieb–Robinson Bounds for Multi–Commutators and Applications to Response Theory
Bru, J.B.; de Siqueira Pedra, W. (2017)We generalize to multicommutators the usual Lieb–Robinson bounds for commutators. In the spirit of constructive QFT, this is done so as to allow the use of combinatorics of minimally connected graphs (tree expansions) in ... 
Macroscopic conductivity of free fermions in disordered media
Bru, J.B.; de Siqueira Pedra, W.; Hertling, C. (20141231)We conclude our analysis of the linear response of charge transport in lattice systems of free fermions subjected to a random potential by deriving general mathematical properties of its conductivity at the macroscopic ... 
Macroscopic Dynamics of the StrongCoupling BCSHubbard Model
Bru, J.B.; de Siqueira Pedra, W. (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 quantumspin systems with longrange, or meanfield, interactions, ... 
Macroscopic Dynamics of the StrongCoupling BCSHubbard Model,
Bru, J.B.; de Siqueira Pedra, W. (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 quantumspin systems with longrange, or meanfield, interactions, ... 
Microscopic conductivity of lattice fermions at equilibrium. I. Noninteracting particles
Bru, J.B.; de Siqueira Pedra, W.; Hertling, C. (20151231)We consider free lattice fermions subjected to a static bounded potential and a timeand spacedependent electric field. For any bounded convex region R âŠ‚ â„ (d (d â‰¥ 1) of space, electric fields Îµ within R drive currents. ... 
Microscopic Conductivity of Lattice Fermions at Equilibrium. Part II: Interacting Particles
Bru, J.B.; de Siqueira Pedra, W. (20160101)We apply Liebâ€“Robinson bounds for multicommutators we recently derived (Bru and de Siqueira Pedra, Liebâ€“Robinson bounds for multicommutators and applications to response theory, 2015) to study the (possibly nonlinear) ...