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We investigate in detail the transference of quantum states in a disordered channel. We consider a one-dimensional tight-binding model consisting of a source S connected to a receiver R throughout a disordered channel. The disorder distribution contains a single tunable spatial correlation length. We demonstrate that the disorder correlation length plays a relevant role within the localization properties of the channel. The hopping parameter between the sites S and R and the channel are also adjustable parameters. We investigate the possibility of transference of quantum states along this quantum channel model and describe the optimal conditions for the occurrence of a high fidelity process. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the one-electron propagation in a nonlinear chain with electron–lattice interaction. The model contains standard cubic nonlinear terms, and we introduce the coupling between the electron and the lattice through the hopping distribution. We solve the coupled equation set to electron and lattice and calculate the electronic position as a function of time. We provide a detailed investigation of the electron and lattice dynamics for a wide range of electron–lattice coupling intensities. Our results demonstrate that depending on the initial condition we consider and the intensity of the electron–lattice interaction, we can obtain (or not) an electron–phonon pair formation. Our results reveal that, depending on the initial velocity of the lattice and the degree of electron–lattice term, we can observe a repulsion between electron and lattice deformations. [ABSTRACT FROM AUTHOR]

In this paper, we consider a square lattice with correlated random hopping terms under the effect of an external electric field. We analyzed the dynamics of an initially localized electronic wave packet using a Taylor formalism to solve the Schrödinger dynamic equation. Our calculations suggest that the correlated disorder promotes a fast electronic propagation for intermediate times. When we switch on a static electric field, we observe an oscillatory behavior similar to the well-known "Bloch oscillations" phenomenology. We calculate the frequency of these oscillations, and our results are in good agreement with those predicted by the semi-classical approach used in crystalline lattices. Based on the local disorder and in the absence of extended states in our model, we discussed the stability of these apparent "Bloch oscillations". [ABSTRACT FROM AUTHOR]

We investigate the spreading of SARS-CoV-2 in the state of Alagoas, northeast of Brazil, via an adaptive susceptible-infected-removed (SIR) model featuring dynamic recuperation and propagation rates. Input parameters are defined based on data made available by Alagoas Secretary of Health from April 19, 2020 on. We provide with the evolution of the basic reproduction number R 0 and reproduce the historical series of the number of confirmed cases with less than 1 0 % error. We offer predictions, from November 16 forward, over the epidemic situation in the near future and show that it will keep decelerating. Furthermore, the same model can be used to study the epidemic dynamics in other countries with great easiness and accuracy. [ABSTRACT FROM AUTHOR]

In this work, we consider a one-electron moving on a Fermi, Pasta, Ulam disordered chain under effect of electron-phonon interaction and a Gaussian acoustic pulse pumping. We describe electronic dynamics using quantum mechanics formalism and the nonlinear atomic vibrations using standard classical physics. Solving numerical equations related to coupled quantum/classical behavior of this system, we study electronic propagation properties. Our calculations suggest that the acoustic pumping associated with the electron-lattice interaction promote a sub-diffusive electronic dynamics. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the influence of electron-lattice interaction on the stability of uniform electronic wavepackets on chains as well as on several types of fullerenes. We will use an effective nonlinear Schrödinger equation to mimic the electron-phonon coupling in these topologies. By numerically solving the nonlinear dynamic equation for an initially uniform electronic wavepacket, we show that the critical nonlinear coupling above which it becomes unstable continuously decreases with the chain size. On the other hand, the critical nonlinear strength saturates on a finite value in large fullerene buckyballs. We also provide analytical arguments to support these findings based on a modulational instability analysis. [ABSTRACT FROM AUTHOR]

We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics. [ABSTRACT FROM AUTHOR]

We address the question regarding the effect of correlated random spring constants in the one-dimensional harmonic model. We consider all masses to be equal but the spring constants given by a random sequence with long-range correlations. We generate the long-range correlated sequence of spring constants by using a fractional Brownian motion with a power-law spectral density S(κ) = 1/κα. Using an exact diagonalization formalism, we compute the participation moments of eigenmodes within the band of allowed frequencies. We unveil a regime on which all modes below a critical frequency become extended. [ABSTRACT FROM AUTHOR]

The Bose-Einstein condensation of noninteracting particles restricted to move on the sites of hierarchical diamond lattices is investigated. Using a tight-binding single-particle Hamiltonian with properly rescaled hopping amplitudes, we are able to employ an orthogonal basis transformation to exactly map it on a set of decoupled linear chains with sizes and degeneracies written in terms of the network branching parameter q and generation number n. The integrated density of states is shown to have a fractal structure of gaps and degeneracies with a power-law decay at the band bottom. The spectral dimension ds coincides with the network topological dimension df = ln(2q)/ln(2). We perform a finite-size scaling analysis of the fraction of condensed particles and specific heat to characterize the critical behavior of the BEC transition that occurs for q > 2 (ds > 2). The critical exponents are shown to follow those for lattices with a pure power-law spectral density, with non-mean-field values for q < 8 (ds < 4). The transition temperature is shown to grow monotonically with the branching parameter, obeying the relation 1/Tc = a + b/(q-2). [ABSTRACT FROM AUTHOR]

In this paper, we study the dynamics of a one-electron in a one-dimensional (1d) alloy with a correlated Ornstein-Uhlenbeck (OU) disorder distribution. The model considered here corresponds to an alloy with three types of atoms where the position of each atom is obtained using a stochastic rule based on the OU process. We analyze in detail the effect of this correlated disorder in the optical absorption spectrum and the level spacing statistics near the band center. Our results reveal a new collection of optical absorption peaks. We explain in details the appearance of each peak. Our calculations about the level spacing's distribution reveals a Poisson distribution thus contradicting previous statements about the existence of extended states in ternary electronic models with correlated disorder distribution. [ABSTRACT FROM AUTHOR]

Vânia Silva Macedo Orsano,1,2 Wilson Max Almeida Monteiro de Moraes,2 Nuno Manuel Frade de Sousa,3 Felipe Carmo de Moura,2 Ramires Alsamir Tibana,4 Alessandro de Oliveira Silva,5 Silvana Schwerz Funghetto,6 Brad J Schoenfeld,7 Jonato Prestes2 1Department of Physical Education, Federal University of Piaui (UFPI), Piauí, Brazil; 2Post Graduation Program on Physical Education, Catholic University of Brasilia (UCB), Brasília, Brazil; 3Laboratory of Exercise Physiology, Faculty Estacio of Vitoria, Espirito Santo, Brazil; 4Department of Physical Education, Federal University of Mato Grosso (UFMT), Mato Grosso, Brazil; 5Faculty of Education and Health Sciences, University Center of Brasilia (UniCEUB), Brasília, Brazil; 6Graduation Program in Health Sciences, University of Brasilia (UnB), Brasília, Brazil; 7Department of Health Sciences, CUNY Lehman College, Bronx, NY, USA Objectives: The aim of the present study was to compare the acute effects of traditional resistance training (RT) versus high velocity RT (HVRT) on metabolic, cardiovascular, and psychophysiological responses in elderly hypertensive women. Methods: Fifteen elderly women (mean age ± standard deviation, 67.1±6.9 years) classified as having hypertension stage 1 or 2 were randomly allocated to complete traditional RT or HVRT; 1 week later, subjects allocated to RT completed the HVRT session and vice-versa. Heart rate, blood pressure, affective response, perceived effort, and blood samples analyzing lactate, nitrate, nitrite, oxidative damage (thiobarbituric acid reactive substances [TBARS]), and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid equivalent antioxidant capacity (TEAC) collected before and after training sessions were assessed. Nutritional counseling was provided regarding nutrients that could affect cardiovascular and nitrate/nitrite analysis. Results: Systolic blood pressure was not statistically different (p>0.05) between conditions at the beginning and during 30 minutes after sessions. Diastolic blood pressure, rate pressure product, and heart rate were not statistically different (p>0.05) between conditions at the beginning and during 45 minutes after sessions. Nitric oxide was significantly higher (p

We study the nature of collective excitations in classical anharmonic lattices with aperiodic and pseudo-random harmonic spring constants. The aperiodicity was introduced in the harmonic potential by using a sinusoidal function whose phase varies as a power-law, ϕ ∝ nν, where n labels the positions along the chain. In the absence of anharmonicity, we numerically demonstrate the existence of extended states and energy propagation for a sufficiently large degree of aperiodicity. Calculations were done by using the transfer matrix formalism (TMF), exact diagonalization and numerical solution of the Hamilton's equations. When nonlinearity is switched on, we numerically obtain a rich framework involving stable and unstable solitons. [ABSTRACT FROM AUTHOR]

In this paper we study the propagation of acoustic waves in a one-dimensional system with nonstationary chaotic elasticity distribution. The elasticity distribution is assumed to have a power spectrum S(f) ~ 1/f(2B-3)/(B-1) for B ≥ 1.5. By using a transfer-matrix method we solve the discrete version of the scalar wave equation and compute the Lyapunov exponent. In addition, we apply a second-order finite-difference method for both the time and spatial variables and study the nature of the waves that propagate in the chain. Our numerical data indicate the presence of weak localized acoustic waves for high degree of correlations (B > 2). [ABSTRACT FROM AUTHOR]

In this paper, we consider the effect of an aperiodic hopping distribution on a single electron. The aperiodic sequence of hopping energies was generated by using a sinusoidal function whose phase ϕ varies as a power-law, ϕ ∝ nν, where n labels the positions along the chain. The exponent ν controls the degree of aperiodicity in the sequence hopping terms. Using the transfer matrix method, we compute the localization length within the band of allowed energies. Our numerical calculations indicate that, for an aperiodic sequence of hopping energies with ν < 1, a new phase of extended states appears in this model. For a pseudorandom hopping distribution with ν > 1, all eigenstates remain localized. In addition, we study the electronic dynamics subjected to an electric field. Our numerical calculations reveals perfect Bloch oscillations for ν < 1. The typical frequency of these oscillations agree with the semiclassical predictions. [ABSTRACT FROM AUTHOR]

We study the nature of the vibrational modes in a two-dimensional harmonic lattice with long-range correlated random masses, with power-law spectral density S(k)∼1/kα. We obtain numerically the scale invariance of the fluctuations of the relative participation number and the local density of states. We find signatures of extended vibrational modes when α>αc and αc depends on the magnitude of disorder. In order to confirm this claim, we also study the time evolution of an initially localized perturbation of the lattice. We show that the second moment of the spatial distribution of the energy displays a ballistic regime when α>αc, in agreement with the occurrence of extended vibrational modes. [ABSTRACT FROM AUTHOR]

We show that the ideal Boson gas displays a finite-temperature Bose-Einstein condensation transition in the complex Apollonian network exhibiting scale-free, small-world, and hierarchical properties. The single-particle tight-binding Hamiltonian with properly rescaled hopping amplitudes has a fractal-like energy spectrum. The energy spectrum is analytically demonstrated to be generated by a nonlinear mapping transformation. A finite-size scaling analysis over several orders of magnitudes of network sizes is shown to provide precise estimates for the exponents characterizing the condensed fraction, correlation size, and specific heat. The critical exponents, as well as the power-law behavior of the density of states at the bottom of the band, are similar to those of the ideal Boson gas in lattices with spectral dimension ds=2ln(3)/ln(9/5)≃3.74. [ABSTRACT FROM AUTHOR]

We study the effects of spatially long-range correlated phase disorder on the Hadamard quantum walk on a line. The shift operator is built to exhibit an intrinsic disorder distribution featuring long-range correlations. To impose such, we resort to fractional Brownian motion with power-law spectrum 1/k2α with α≥0 being the exponent that controls the degree of correlations. We discuss the scaling behavior of the walker's wave packet and report a localization-delocalization transition controlled by α. We unveil two intermediate dynamical regimes between exponential localization and full delocalization. [ABSTRACT FROM AUTHOR]

We consider interacting electrons moving in a nonlinear Morse lattice. We set the initial conditions as follows: electrons were initially localized at the center of the chain and a solitonic deformation was produced by an impulse excitation on the center of the chain. By solving quantum and classical equations for this system numerically, we found that a fraction of electronic wave function was trapped by the solitonic excitation, and trapping specificities depend on the degree of interaction among electrons. Also, there is evidence that the effective electron velocity depends on Coulomb interaction and electron-phonon coupling in a nontrivial way. This association is explained in detail along this work. In addition, we briefly discuss the dependence of our results with the type of initial condition we choose for the electrons and lattice. [ABSTRACT FROM AUTHOR]