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2015-04-29
Wide-Range Tunable Dynamic Property of Carbon Nanotube-Based Fibers
Carbon nanotube (CNT) fiber is formed by assembling millions of individual tubes. The assembly feature provides the fiber with rich interface structures and thus various ways of energy dissipation, as reflected by the non-zero loss tangent (>0.028--0.045) at low vibration frequencies. A fiber containing entangled CNTs ...
1504.07881v1
2015-05-10
Effects of electron drift on the collisionless damping of kinetic Alfvén waves in the solar wind
The collisionless dissipation of anisotropic Alfv\'enic turbulence is a promising candidate to solve the solar wind heating problem. Extensive studies examined the kinetic properties of Alfv\'en waves in simple Maxwellian or bi-Maxwellian plasmas. However, the observed electron velocity distribution functions in the so...
1505.02328v1
2015-05-13
The effect of a reversible shear transformation on plastic deformation of an amorphous solid
Molecular dynamics simulations are performed to investigate the plastic response of a model glass to a local shear transformation in a quiescent system. The deformation of the material is induced by a spherical inclusion that is gradually strained into an ellipsoid of the same volume and then reverted back into the sph...
1505.03488v1
2015-05-14
Local large deviations principle for occupation measures of the damped nonlinear wave equation perturbed by a white noise
We consider the damped nonlinear wave (NLW) equation driven by a spatially regular white noise. Assuming that the noise is non-degenerate in all Fourier modes, we establish a large deviations principle (LDP) for the occupation measures of the trajectories. The lower bound in the LDP is of a local type, which is related...
1505.03686v1
2015-05-19
Undamped nonequilibrium dynamics of a nondegenerate Bose gas in a 3D isotropic trap
We investigate anomalous damping of the monopole mode of a non-degenerate 3D Bose gas under isotropic harmonic confinement as recently reported by the JILA TOP trap experiment [D. S. Lob- ser, A. E. S. Barentine, E. A. Cornell, and H. J. Lewandowski (in preparation)]. Given a realistic confining potential, we develop a...
1505.04841v1
2015-05-21
Control and stabilization of degenerate wave equations
We study a wave equation in one space dimension with a general diffusion coefficient which degenerates on part of the boundary. Degeneracy is measured by a real parameter $\mu_a>0$. We establish observability inequalities for weakly (when $\mu_a \in [0,1[$) as well as strongly (when $\mu_a \in [1,2[$) degenerate equati...
1505.05720v1
2015-05-23
Existence, blow-up and exponential decay of solutions for a porous-elastic system with damping and source terms
In this paper we consider a porous-elastic system consisting of nonlinear boundary/interior damping and nonlinear boundary/interior sources. Our interest lies in the theoretical understanding of the existence, finite time blow-up of solutions and their exponential decay using non-trivial adaptations of well-known techn...
1505.06373v2
2015-05-26
Quantum Particle Motion in Absorbing Harmonic Trap
The motivation of this work is to get an additional insight into the irreversible energy dissipation on the quantum level. The presented examination procedure is based on the Feynman path integral method that is applied and widened towards the calculation of the kernel of a quantum mechanical damped oscillator. Here, i...
1505.06874v1
2015-06-03
Non-uniqueness of Admissible Weak Solutions to Compressible Euler Systems with Source Terms
We consider admissible weak solutions to the compressible Euler system with source terms, which include rotating shallow water system and the Euler system with damping as special examples. In the case of anti-symmetric sources such as rotations, for general piecewise Lipschitz initial densities and some suitably constr...
1506.01103v1
2015-06-03
The effect of perpendicular electric field on Temperature-induced plasmon excitations for intrinsic silicene
We use the tight-binding model and the random-phase approximation to investigate the intrinsic plasmon in silicene. At finite temperatures, an undamped plasmon is generated from the interplay between the intraband and the interband-gap transitions. The extent of the plasmon existence range in terms of momentum and temp...
1506.01140v1
2015-06-09
Transport Barrier generation at the interface of regions with different zonal flows dynamics
A novel and generic understanding of spontaneous generation of transport barriers and zonation regimes in turbulent self-organization is presented. It associates the barrier onset to the development of a spectral gap between large scale flows and turbulence modes leading to a zonation regime. A robust barrier builds-up...
1506.02942v2
2015-06-11
Fighting noise with noise in realistic quantum teleportation
We investigate how the efficiency of the quantum teleportation protocol is affected when the qubits involved in the protocol are subjected to noise or decoherence. We study all types of noise usually encountered in real world implementations of quantum communication protocols, namely, the bit flip, phase flip (phase da...
1506.03803v2
2015-07-08
Low-Dimensional Stochastic Projected Gross-Pitaevskii Equation
We present reduced-dimensional stochastic projected Gross-Pitaevskii equations describing regimes of confinement and temperature where a 1D or 2D superfluid is immersed in a 3D thermal cloud. The projection formalism provides both a formally rigorous and physically natural way to effect the dimensional reduction. The 3...
1507.02023v2
2015-07-08
Low-emittance storage rings
The effects of synchrotron radiation on particle motion in storage rings are discussed. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. The inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the damping times are der...
1507.02213v1
2015-07-09
Controlling the stability of steady states in continuous variable quantum systems
For the paradigmatic case of the damped quantum harmonic oscillator we present two measurement-based feedback schemes to control the stability of its fixed point. The first scheme feeds back a Pyragas-like time-delayed reference signal and the second uses a predetermined instead of time-delayed reference signal. We sho...
1507.02538v1
2015-07-14
WIMP isocurvature perturbation and small scale structure
The adiabatic perturbation of dark matter is damped during the kinetic decoupling due to the collision with relativistic component on sub-horizon scales. However the isocurvature part is free from damping and could be large enough to make a substantial contribution to the formation of small scale structure. We explicit...
1507.03871v2
2015-07-17
Pairwise quantum discord for a symmetric multi-qubit system in different types of noisy channels
We study the pairwise quantum discord (QD) for a symmetric multi-qubit system in different types of noisy channels, such as phase-flip, amplitude damping, phase-damping, and depolarizing channels. Using the QD and geometric measure of quantum discord (GMQD) to quantify quantum correlations, some analytical or numerical...
1507.04826v1
2015-07-20
Landau damping effects in the synchronization of conformist and contrarian oscillators
Two decades ago, a phenomenon resembling Landau damping was described in the synchronization of globally coupled oscillators: the evidence of a regime where the order parameter decays when linear theory predicts neutral stability for the incoherent state. We here show that such an effect is far more generic, as soon as...
1507.05383v1
2015-07-28
Attractors for Strongly Damped Wave Equations with Nonlinear Hyperbolic Dynamic Boundary Conditions
We establish the well-posedness of a strongly damped semilinear wave equation equipped with nonlinear hyperbolic dynamic boundary conditions. Results are carried out with the presence of a parameter distinguishing whether the underlying operator is analytic, $\alpha>0$, or only of Gevrey class, $\alpha=0$. We establish...
1507.07971v1
2015-07-29
Neimark--Sacker bifurcation and evidence of chaos in a discrete dynamical model of walkers
Bouncing droplets on a vibrating fluid bath can exhibit wave-particle behavior, such as being propelled by interacting with its own wave field. These droplets seem to walk across the bath, and thus are dubbed walkers. Experiments have shown that walkers can exhibit exotic dynamical behavior indicative of chaos. While t...
1507.08057v2
2015-07-30
Beliaev damping of the Goldstone mode in atomic Fermi superfluids
Beliaev damping in a superfluid is the decay of a collective excitation into two lower frequency collective excitations; it represents the only decay mode for a bosonic collective excitation in a superfluid at T = 0. The standard treatment for this decay assumes a linear spectrum, which in turn implies that the final s...
1507.08535v1
2015-08-09
Small quantum absorption refrigerator in the transient regime: time scales, enhanced cooling and entanglement
A small quantum absorption refrigerator, consisting of three qubits, is discussed in the transient regime. We discuss time scales for coherent dynamics, damping, and approach to the steady state, and we study cooling and entanglement. We observe that cooling can be enhanced in the transient regime, in the sense that lo...
1508.02025v2
2015-08-13
Hybridization of Higgs modes in a bond-density-wave state in cuprates
Recently, several groups have reported observations of collective modes of the charge order present in underdoped cuprates. Motivated by these experiments, we study theoretically the oscillations of the order parameters, both in the case of pure charge order, and for charge order coexisting with superconductivity. Usin...
1508.03335v1
2015-08-18
Negative nonlinear damping of a graphene mechanical resonator
We experimentally investigate the nonlinear response of a multilayer graphene resonator using a superconducting microwave cavity to detect its motion. The radiation pressure force is used to drive the mechanical resonator in an optomechanically induced transparency configuration. By varying the amplitudes of drive and ...
1508.04298v1
2015-08-21
Formulation and solutions of fractional continuously variable order mass spring damper systems controlled by viscoelastic and viscous-viscoelastic dampers
The article presents the formulation and a new approach to find analytic solutions for fractional continuously variable order dynamic models viz. Fractional continuously variable order mass-spring damper systems. Here, we use the viscoelastic and viscous-viscoelastic dampers for describing the damping nature of the osc...
1508.06202v1
2015-08-25
Simultaneous cooling of coupled mechanical oscillators using whispering gallery mode resonances
We demonstrate simultaneous center-of-mass cooling of two coupled oscillators, consisting of a microsphere-cantilever and a tapered optical fiber. Excitation of a whispering gallery mode (WGM) of the microsphere, via the evanescent field of the taper, provides a transduction signal that continuously monitors the relati...
1508.06217v2
2015-08-31
Damping of a system of linear oscillators using the generalized dry friction
The problem of damping a system of linear oscillators is considered. The problem is solved by using a control in the form of dry friction. The motion of the system under the control is governed by a system of differential equations with discontinuous right-hand side. A uniqueness and continuity theorem is proved for th...
1508.07775v2
2015-09-02
Smoothing and Global Attractors for the Majda-Biello System on the Torus
In this paper, we consider the Majda-Biello system, a coupled KdV-type system, on the torus. In the first part of the paper, it is shown that, given initial data in a Sobolev space, the difference between the linear and the nonlinear evolution almost always resides in a smoother space. The smoothing index depends on nu...
1509.00776v1
2015-09-07
Non-linear Cosmic Ray propagation close to the acceleration site
Recent advances on gamma-ray observations from SuperNova Remnants and Molecular Clouds offer the possibility to study in detail the properties of the propagation of escaping Cosmic Rays (CR). However, a complete theory for CR transport outside the acceleration site has not been developed yet. Two physical processes are...
1509.02174v1
2015-09-10
Strain-dependent damping in nanomechanical resonators from thin $\mathrm{MoS_2}$ crystals
We investigate the effect of mechanical strain on the dynamics of thin $\mathrm{MoS_2}$ nanodrum resonators. Using a piezoelectric crystal, compressive and tensile biaxial strain is induced in initially flat and buckled devices. In the flat device, we observe a remarkable strain-dependence of the resonance line width, ...
1509.03080v1
2015-09-16
Variational principle for magnetisation dynamics in a temperature gradient
By applying a variational principle on a magnetic system within the framework of extended irreversible thermodynamics, we find that the presence of a temperature gradient in a ferromagnet leads to a generalisation of the Landau-Lifshitz equation with an additional magnetic induction field proportional to the temperatur...
1509.04825v2
2015-10-01
Dilapidation of nonlocal correlations of two qubit states in noisy environment
Composite quantum systems exhibit non-local correlations. These counter intuitive correlations form a resource for quantum information processing and quantum computation. In our previous work on two qubit maximally entangled mixed states, we observed that entangled states, states that can be used for quantum teleportai...
1510.00119v1
2015-10-01
Production of charged Higgs boson pairs in the $pp \to ppH^{+}H^{-}$ reaction at the LHC and FCC
We present differential cross sections for the $pp \to ppH^{+}H^{-}$ reaction via photon-photon fusion with exact kinematics. We show predictions for $\sqrt{s}$ = 14 TeV (LHC) and at the Future Circular Collider (FCC) for $\sqrt{s}$ = 100 TeV. The integrated cross section for $\sqrt{s}$ = 14~TeV (LHC) is about 0.1~fb a...
1510.00171v1
2015-10-05
Universality in antiferromagnetic strange metals
We propose a theory of metals at the spin-density wave quantum critical point in spatial dimension $d=2$. We provide a first estimate of the full set of critical exponents (dynamical exponent $z=2.13$, correlation length $\nu =1.02$, spin susceptibility $\gamma = 0.96$, electronic non-Fermi liquid $\eta^f_\tau = 0.53$,...
1510.01331v3
2015-10-09
Spin-orbit torque in Pt/CoNiCo/Pt symmetric devices
Current induced magnetization switching by spin-orbit torques offers an energy-efficient means of writing information in heavy metal/ferromagnet (FM) multilayer systems. The relative contributions of field-like torques and damping-like torques to the magnetization switching induced by the electrical current are still u...
1510.02555v1
2015-10-15
On the global existence and blowup of smooth solutions of 3-D compressible Euler equations with time-depending damping
In this paper, we are concerned with the global existence and blowup of smooth solutions of the 3-D compressible Euler equation with time-depending damping $$ \partial_t\rho+\operatorname{div}(\rho u)=0, \quad \partial_t(\rho u)+\operatorname{div}\left(\rho u\otimes u+p\,I_{3}\right)=-\,\frac{\mu}{(1+t)^{\lambda}...
1510.04613v1
2015-10-17
Direct evidence for minority spin gap in the Co2MnSi Heusler alloy
Half Metal Magnets are of great interest in the field of spintronics because of their potential full spin-polarization at the Fermi level and low magnetization damping. The high Curie temperature and predicted 0.7eV minority spin gap make the Heusler alloy Co2MnSi very promising for applications.We investigated the hal...
1510.05085v1
2015-10-18
Information transmission over an amplitude damping channel with an arbitrary degree of memory
We study the performance of a partially correlated amplitude damping channel acting on two qubits. We derive lower bounds for the single-shot classical capacity by studying two kinds of quantum ensembles, one which allows to maximize the Holevo quantity for the memoryless channel and the other allowing the same task bu...
1510.05313v1
2015-10-29
A Semismooth Newton Method for Tensor Eigenvalue Complementarity Problem
In this paper, we consider the tensor eigenvalue complementarity problem which is closely related to the optimality conditions for polynomial optimization, as well as a class of differential inclusions with nonconvex processes. By introducing an NCP-function, we reformulate the tensor eigenvalue complementarity problem...
1510.08570v1
2015-11-15
Mode coupling in solar spicule oscillations
In a real medium which has oscillations, the perturbations can cause the energy transfer between different modes. The perturbation interpreted as an interaction between the modes is inferred as mode coupling. Mode coupling process in an inhomogeneous medium such as solar spicules may lead to the coupling of kink waves ...
1511.05135v1
2015-11-19
Resurgence in Extended Hydrodynamics
It has recently been understood that the hydrodynamic series generated by the M\"uller-Israel-Stewart theory is divergent, and that this large order behaviour is consistent with the theory of resurgence. Furthermore, it was observed, that the physical origin of this is the presence of a purely damped nonhydrodynamic mo...
1511.06358v2
2015-12-02
Flow of colloidal solids and fluids through constrictions: dynamical density functional theory versus simulation
Using both dynamical density functional theory and particle-resolved Brownian dynamics simulations, we explore the flow of two-dimensional colloidal solids and fluids driven through a linear channel with a geometric constriction. The flow is generated by a constant external force acting on all colloids. The initial con...
1512.00751v1
2015-12-04
Numerical solution of the stationary multicomponent nonlinear Schrödinger equation with a constraint on the angular momentum
We formulate a damped oscillating particle method to solve the stationary nonlinear Schr\"{o}dinger equation (NLSE). The ground state solutions are found by a converging damped oscillating evolution equation that can be discretized with symplectic numerical techniques. The method is demonstrated for three different cas...
1512.01441v2
2015-12-08
Influence of kinetic effects on the spectrum of a parallel electrode probe
Active Plasma Resonance Spectroscopy (APRS) denotes a class of diagnostic techniques which utilize the natural ability of plasmas to resonate on or near the electron plasma frequency. One particular class of APRS can be described in an abstract notation based on functional analytic methods in electrostatic approximatio...
1512.02450v1
2015-12-09
Long time behaviors for 3D cubic damped Klein-Gordon equations in inhomogeneous mediums
In this paper, we study the asymptotic dynamics of global solutions to damped Klein-Gordon equations in inhomogeneous mediums (KGI). In the defocusing case, we prove for any initial data, the solution is globally define in forward time and it will converge to an equilibrium. In the focusing case, for global solutions, ...
1512.02755v3
2015-12-10
Strong Frequency Dependence in Over-damped Systems
Strong frequency dependence is unlikely in diffusive or over-damped systems. When exceptions do occur, such as in the case of stochastic resonance, it signals an interesting underlying phenomenon. We find that such a case appears in the motion of a particle in a diffusive environment under the effect of periodically os...
1512.03187v1
2015-12-16
Back to Maupertuis' least action principle for dissipative systems: not all motions in Nature are most energy economical
It is shown that an oldest form of variational calculus of mechanics, the Maupertuis least action principle, can be used as a simple and powerful approach for the formulation of the variational principle for damped motions, allowing a simple derivation of the Lagrangian mechanics for any dissipative systems and an a co...
1512.05339v1
2016-01-11
Damping of Landau levels in neutral graphene at low magnetic fields: A phonon Raman scattering study
Landau level broadening mechanisms in electrically neutral and quasineutral graphene were investigated through micro-magneto-Raman experiments in three different samples, namely, a natural single-layer graphene flake and a back-gated single-layer device, both deposited over Si/SiO2 substrates, and a multilayer epitaxia...
1601.02663v3
2016-01-21
Negative frequencies in wave propagation: a microscopic model
A change in the sign of the frequency of a wave between two inertial reference frames corresponds to a reversal of the phase velocity. Yet from the point of view of the relation $E=\hbar\omega$, a positive quantum of energy apparently becomes a negative energy one. This is physically distinct from a change in the sign ...
1601.05636v1
2016-01-26
On the wave equation with hyperbolic dynamical boundary conditions, interior and boundary damping and supercritical sources
The aim of the paper is to study the problem $$ \begin{cases} u_{tt}-\Delta u+P(x,u_t)=f(x,u) \qquad &\text{in $(0,\infty)\times\Omega$,} u=0 &\text{on $(0,\infty)\times \Gamma_0$,} u_{tt}+\partial_\nu u-\Delta_\Gamma u+Q(x,u_t)=g(x,u)\qquad &\text{on $(0,\infty)\times \Gamma_1$,} u(0,x)=u_0(x),\quad u_t(0,x)=u_1(x) & ...
1601.07075v3
2016-01-29
Numerical Simulation of Tidal Evolution of a Viscoelastic Body Modelled with a Mass-Spring Network
We use a damped mass-spring model within an N-body code to simulate the tidal evolution of the spin and orbit of a self-gravitating viscoelastic spherical body moving around a point-mass perturber. The damped mass-spring model represents a Kelvin-Voigt viscoelastic solid. We measure the tidal quality function (the dyna...
1601.08222v2
2016-02-04
Highly efficient two photon generation from a coherently pumped quantum dot embedded in a microcavity
We propose a scheme to realize a highly efficient solid state source of photon pairs using cavity-assisted stimulated Raman adiabatic passage (STIRAP) in a single quantum dot, where a single photon from pump pulse and two stokes photons from cavity mode drives the Raman transition. The Autler-Townes doublet, generated ...
1602.01562v1
2016-02-09
Preservation of quantum key rate in the presence of decoherence
It is well known that the interaction of quantum systems with the environment reduces the inherent quantum correlations. Under special circumstances the effect of decoherence can be reversed, for example, the interaction modeled by an amplitude damping channel can boost the teleportation fidelity from the classical to ...
1602.02903v1
2016-02-19
An accelerated exponential time integrator for semi-linear stochastic strongly damped wave equation with additive noise
This paper is concerned with the strong approximation of a semi-linear stochastic wave equation with strong damping, driven by additive noise. Based on a spatial discretization performed by a spectral Galerkin method, we introduce a kind of accelerated exponential time integrator involving linear functionals of the noi...
1602.06050v1
2016-02-23
The calibration and electron energy reconstruction of the BGO ECAL of the DAMPE detector
The DArk Matter Particle Explorer (DAMPE) is a space experiment designed to search for dark matter indirectly by measuring the spectra of photons, electrons, and positrons up to 10 TeV. The BGO electromagnetic calorimeter (ECAL) is its main sub-detector for energy measurement. In this paper, the instrumentation and dev...
1602.07015v1
2016-02-25
Order-disorder transition in repulsive self-propelled particle systems
We study the collective dynamics of repulsive self-propelled particles. The particles are governed by coupled equations of motion that include polar self-propulsion, damping of velocity and of polarity, repulsive particle-particle interaction, and deterministic dynamics. Particle dynamics simulations show that the coll...
1602.07971v2
2016-03-01
Ferromagnetic resonance and magnetic damping in C-doped Mn5Ge3
Ferromagnetic resonance (FMR) was used to investigate the static and dynamic magnetic properties of carbon-doped Mn5Ge3 (C$_{0.1}$ and C$_{0.2}$) thin films grown on Ge(111). The temperature dependence of magnetic anisotropy shows an increased perpendicular magneto-crystalline contribution at 80K with an in-plane easy ...
1603.00190v1
2016-03-01
Probing superfluidity in a quasi two-dimensional Bose gas through its local dynamics
We report direct evidence of superfluidity in a quasi two-dimensional Bose gas by observing its dynamical response to a collective excitation. Relying on a novel local correlation analysis, we are able to probe inhomogeneous clouds and reveal their local dynamics. We identify in this way the superfluid and thermal phas...
1603.00434v2
2016-03-03
Backreaction Effects on Nonequilibrium Spectral Function
We show how to compute the spectral function for a scalar theory in two different scenarios: one which disregards back-reaction i.e. the response of the environment to the external particle, and the other one where back-reaction is considered. The calculation was performed using the Kadanoff-Baym equation through the K...
1603.01118v1
2016-04-06
Brownian motion of a matter-wave bright soliton: realizing a quantum pollen grain
Taking an open quantum systems approach, we derive a collective equation of motion for the dynamics of a matter-wave bright soliton moving through a thermal cloud of a distinct atomic species. The reservoir interaction involves energy transfer without particle transfer between the soliton and thermal cloud, thus dampin...
1604.01487v1
2016-04-06
Quantum backaction and noise interference in asymmetric two-cavity optomechanical systems
We study the effect of cavity damping asymmetries on backaction in a "membrane-in-the-middle" optomechanical system, where a mechanical mode modulates the coupling between two photonic modes. We show that in the adiabatic limit, this system generically realizes a dissipative optomechanical coupling, with an effective p...
1604.01703v1
2016-04-08
Discrete Breathers and Multi-Breathers in Finite Vibro-Impact Chain
We explore dynamics of discrete breathers and multi-breathers in finite one-dimensional chain. The model involves parabolic on-site potential with rigid constraints and linear nearest-neighbor coupling. The rigid non-ideal impact constraints are the only source of nonlinearity and damping in the model. The model allows...
1604.02296v1
2016-04-22
A Liapunov function approach to the stabilization of second order coupled systems
In 2002, Fatiha Alabau, Piermarco Cannarsa and Vilmos Komornik investigated the extent of asymptotic stability of the null solution for weakly coupled partially damped equations of the second order in time. The main point is that the damping operator acts only on the first component and, whenever it is bounded, the cou...
1604.06547v1
2016-04-28
Temperature Dependence of Viscosity in Normal Fluid $^3$He Below 800mK Determined by a Micro-electro-mechanical Oscillator
A micro-electro-mechanical system vibrating in its shear mode was used to study the viscosity of normal liquid $^3$He from 20mK to 770mK at 3bar, 21bar, and 29bar. The damping coefficient of the oscillator was determined by frequency sweeps through its resonance at each temperature. Using a slide film damping model, th...
1604.08554v1
2016-05-01
Optical trapping by Laguerre-Gaussian beams: Symmetries, stability and equilibria
We use the T-matrix formalism in combination with the method of far-field matching to evaluate the optical force exerted by Laguerre-Gaussian (LG) light beams on a spherical (Mie) particle. For both non-vortex and optical vortex LG beams, the theoretical results are used to analyze the optical-force-induced dynamics of...
1605.00243v2
2016-05-03
Including atomic vibrations in XANES calculations: polarization-dependent damping of the fine structure at the Cu K edge of (creat)$_{2}$CuCl$_{4}$
Atomic vibrations are usually not taken into account when analyzing x-ray absorption near edge structure (XANES) spectra. One of the reasons is that including the vibrations in a formally exact way is quite complicated while the effect of vibrations is supposed to be small in the XANES region. By analyzing polarized Cu...
1605.00861v1
2016-05-05
Relaxation of Ferroelectric States in 2D Distributions of quantum Dots:EELS Simulation
The relaxation time of collective electronic states in a 2D distribution of quantum dots is investigated theoretically by simulating EELS experiments. From the numerical calculation of the probability of energy loss of an electron beam, traveling parallel to the distribution, it is possible to estimate the damping time...
1605.01642v1
2016-05-10
Damped wave systems on networks: Exponential stability and uniform approximations
We consider a damped linear hyperbolic system modelling the propagation of pressure waves in a network of pipes. Well-posedness is established via semi-group theory and the existence of a unique steady state is proven in the absence of driving forces. Under mild assumptions on the network topology and the model paramet...
1605.03066v1
2016-05-14
The damped oscillating propagation of the compensating self-accelerating beams
We report a new form of compensating accelerating beam generated by amplitude modulation of the symmetric Airy beam (SAB) caustics with an exponential apodization mask. Our numerical study manifests that the compensating beam is with one main-lobe beam structure and can maintain the mean-intensity invariant both in the...
1605.04392v1
2016-05-14
Detecting Damped Lyman-$α$ Absorbers with Gaussian Processes
We develop an automated technique for detecting damped Lyman-$\alpha$ absorbers (DLAs) along spectroscopic lines of sight to quasi-stellar objects (QSOs or quasars). The detection of DLAs in large-scale spectroscopic surveys such as SDSS-III sheds light on galaxy formation at high redshift, showing the nucleation of ga...
1605.04460v2
2016-05-17
Direct observation of dynamic modes excited in a magnetic insulator by pure spin current
Excitation of magnetization dynamics by pure spin currents has been recently recognized as an enabling mechanism for spintronics and magnonics, which allows implementation of spin-torque devices based on low-damping insulating magnetic materials. Here we report the first spatially-resolved study of the dynamic modes ex...
1605.05211v1
2016-05-18
Damped Arrow-Hurwicz algorithm for sphere packing
We consider algorithms that, from an arbitrarily sampling of $N$ spheres (possibly overlapping), find a close packed configuration without overlapping. These problems can be formulated as minimization problems with non-convex constraints. For such packing problems, we observe that the classical iterative Arrow-Hurwicz ...
1605.05473v1
2016-05-17
Dynamics of sessile drops. Part 3. Theory of forced oscillations
A partially-wetting sessile drop is driven by a sinusoidal pressure field that produces capillary waves on the liquid/gas interface. The analysis presented in Part 1 of this series (Bostwick & Steen 2014) is extended by computing response diagrams and phase shifts for the viscous droplet, whose three phase contact-line...
1605.05533v1
2016-05-18
Electrical control over perpendicular magnetization switching driven by spin-orbit torques
Flexible control of magnetization switching by electrical manners is crucial for applications of spin-orbitronics. Besides of a switching current that is parallel to an applied field, a bias current that is normal to the switching current is introduced to tune the magnitude of effective damping-like and field-like torq...
1605.05569v1
2016-05-25
Quadratic band touching with long range interactions in and out of equilibrium
Motivated by recent advances in cold atomic systems, we study the equilibrium and quench properties of two dimensional fermions with quadratic band touching at the Fermi level, in the presence of infinitely long range interactions. Unlike when only short range interactions are present, both nematic and quantum anomalou...
1605.07932v1
2016-05-26
Asymmetric Quantum Dialogue in Noisy Environment
A notion of asymmetric quantum dialogue (AQD) is introduced. Conventional protocols of quantum dialogue are essentially symmetric as both the users (Alice and Bob) can encode the same amount of classical information. In contrast, the scheme for AQD introduced here provides different amount of communication powers to Al...
1605.08363v1
2016-06-11
Parameter identification in a semilinear hyperbolic system
We consider the identification of a nonlinear friction law in a one-dimensional damped wave equation from additional boundary measurements. Well-posedness of the governing semilinear hyperbolic system is established via semigroup theory and contraction arguments. We then investigte the inverse problem of recovering the...
1606.03580v1
2016-06-16
Design of the readout electronics for the DAMPE Silicon Tracker detector
The Silicon Tracker (STK) is a detector of the DAMPE satellite to measure the incidence direction of high energy cosmic ray. It consists of 6 X-Y double layers of silicon micro-strip detectors with 73,728 readout channels. It's a great challenge to readout the channels and process the huge volume of data in the critica...
1606.05080v1
2016-06-20
Classical analogue of the continuous transition between the Weisskopf-Wigner exponential decay and the Rabi oscillation
When a discrete state is coupled to a continuum, the dynamics can be described either by the Weisskopf-Wigner exponential decay or by the Rabi oscillation, depending on the relative magnitudes of the continuum width and of the Rabi frequency. A continuous transition between these two regimes exists, as demonstrated in ...
1606.06153v1
2016-07-05
Quantum Zeno and Anti-Zeno Effects on the Entanglement Dynamics of Qubits Dissipating into a Common and non-Markovian Environment
We investigate the quantum Zeno and anti-Zeno effects on pairwise entanglement dynamics of a collective of non-interacting qubits which have been initially prepared in a Werner state and are off-resonantly coupled to a common and non-Markovian environment. We obtain the analytical expression of the concurrence in the a...
1607.01160v1
2016-07-27
Linear and nonlinear viscoelastic arterial wall models: application on animals
This work deals with the viscoelasticity of the arterial wall and its influence on the pulse waves. We describe the viscoelasticity by a non-linear Kelvin-Voigt model in which the coefficients are fitted using experimental time series of pressure and radius measured on a sheep's arterial network. We obtained a good agr...
1607.07973v1
2016-08-03
Ultra-Low Dissipation Superfluid Micromechanical Resonator
Micro and nanomechanical resonators with ultra-low dissipation have great potential as useful quantum resources. The superfluid micromechanical resonators presented here possess several advantageous characteristics: straightforward thermalization, dissipationless flow, and in situ tunability. We identify and quantitati...
1608.01380v1
2016-08-14
A second order dynamical system with Hessian-driven damping and penalty term associated to variational inequalities
We consider the minimization of a convex objective function subject to the set of minima of another convex function, under the assumption that both functions are twice continuously differentiable. We approach this optimization problem from a continuous perspective by means of a second order dynamical system with Hessia...
1608.04137v1
2016-08-15
Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence
We make quantitative estimates of the power supplied to the Galactic cosmic ray population by second-order Fermi acceleration in the interstellar medium, or as it is usually termed in cosmic ray propagation studies, diffusive reacceleration. Using recent results on the local interstellar spectrum from the Voyager missi...
1608.04227v2
2016-08-19
Cooling a harmonic oscillator by optomechanical modification of its bath
Optomechanical systems show tremendous promise for high sensitivity sensing of forces and modification of mechanical properties via light. For example, similar to neutral atoms and trapped ions, laser cooling of mechanical motion by radiation pressure can take single mechanical modes to their ground state. Conventional...
1608.05717v1
2016-09-01
Observation of oscillatory radial electric field relaxation in a helical plasma
Measurements of the relaxation of a zonal electrostatic potential perturbation in a non-axisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma equilibrium is induced by the injection of a cryogenic hydrogen pellet in the TJ-II stellarator, which is observed to be followed by a damp...
1609.00281v1
2016-09-10
Stochastic Sampling for Structural Topology Optimization with Many Load Cases: Density-Based and Ground Structure Approaches
We propose an efficient probabilistic method to solve a deterministic problem -- we present a randomized optimization approach that drastically reduces the enormous computational cost of optimizing designs under many load cases for both continuum and truss topology optimization. Practical structural designs by topology...
1609.03099v1
2016-09-15
Low-damping sub-10-nm thin films of lutetium iron garnet grown by molecular-beam epitaxy
We analyze the structural and magnetic characteristics of (111)-oriented lutetium iron garnet (Lu$_3$Fe$_5$O$_{12}$) films grown by molecular-beam epitaxy, for films as thin as 2.8 nm. Thickness-dependent measurements of the in- and out-of-plane ferromagnetic resonance allow us to quantify the effects of two-magnon sca...
1609.04753v1
2016-09-18
Inertia effects in the real-time dynamics of a quantum spin coupled to a Fermi sea
Spin dynamics in the Kondo impurity model, initiated by suddenly switching the direction of a local magnetic field, is studied by means of the time-dependent density-matrix renormalization group. Quantum effects are identified by systematic computations for different spin quantum numbers $S$ and by comparing with tight...
1609.05526v1
2016-09-21
Force sensitivity of multilayer graphene optomechanical devices
Mechanical resonators based on low-dimensional materials are promising for force and mass sensing experiments. The force sensitivity in these ultra-light resonators is often limited by the imprecision in the measurement of the vibrations, the fluctuations of the mechanical resonant frequency, and the heating induced by...
1609.06517v1
2016-09-26
Ferromagnetic resonance study of composite Co/Ni - FeCoB free layers with perpendicular anisotropy
We study the properties of composite free layers with perpendicular anisotropy. The free layers are made of a soft FeCoB layer ferromagnetically coupled by a variable spacer (Ta, W, Mo) to a very anisotropic [Co/Ni] multilayer embodied in a magnetic tunnel junction meant for spin torque memory applications. For this we...
1609.07863v1
2016-09-30
Origin of the effective mobility in non-linear active micro-rheology
The distinction between the damping coefficient and the effective non-linear mobility of driven particles in active micro-rheology of supercooled liquids is explained in terms of individual and collective dynamics. The effective mobility arises as a collective effect which gives insight into the energy landscape of the...
1609.09853v1
2016-10-03
Inertia and universality of avalanche statistics: The case of slowly deformed amorphous solids
By means of a finite elements technique we solve numerically the dynamics of an amorphous solid under deformation in the quasistatic driving limit. We study the noise statistics of the stress-strain signal in the steady state plastic flow, focusing on systems with low internal dissipation. We analyze the distributions ...
1610.00533v2
2016-10-04
Statistical properties of damped Lyman-alpha systems from Sloan Digital Sky Survey DR12
We present new estimates for the statistical properties of damped Lyman-$\alpha$ absorbers (DLAs). We compute the column density distribution function at $z>2$, the line density, $\mathrm{d}N/\mathrm{d}X$, and the neutral hydrogen density, $\Omega_\mathrm{DLA}$. Our estimates are derived from the DLA catalogue of Garne...
1610.01165v2
2016-10-05
Higher-Harmonic Collective Modes in a Trapped Gas from Second-Order Hydrodynamics
Utilizing a second-order hydrodynamics formalism, the dispersion relations for the frequencies and damping rates of collective oscillations as well as spatial structure of these modes up to the decapole oscillation in both two- and three- dimensional gas geometries are calculated. In addition to higher-order modes, the...
1610.01611v2
2016-10-10
Robust force sensing for a free particle in a dissipative optomechanical system with a parametric amplifier
We theoretically investigate optical detection of a weak classical force acting on a free particle in a dissipative coupling optomechanical system with a degenerate parametric amplifier (PA). We show that the PA allows one to achieve the force sensitivity far better than the standard quantum limit (SQL) over a broad ra...
1610.02761v2
2016-10-12
Stabilization of the Gear-Grimshaw system with weak damping
The aim of this work is to consider the internal stabilization of a nonlinear coupled system of two Korteweg--de Vries equations in a finite interval under the effect of a very weak localized damping. The system was introduced by Gear and Grimshaw to model the interactions of two-dimensional, long, internal gravity wav...
1610.03829v4
2016-10-16
Pulse-noise approach for classical spin systems
For systems of classical spins interacting with the bath via damping and thermal noise, the approach is suggested to replace the white noise by a pulse noise acting at regular time intervals $\Delta t$, within which the system evolves conservatively. The method is working well in the typical case of a small dimensionle...
1610.04914v2
2016-10-19
Heavy-tailed response of structural systems subjected to stochastic excitation containing extreme forcing events
We characterize the complex, heavy-tailed probability distribution functions (pdf) describing the response and its local extrema for structural systems subjected to random forcing that includes extreme events. Our approach is based on the recent probabilistic decomposition-synthesis technique, where we decouple rare ev...
1610.06110v3
2016-10-27
Thermally activated phase slips of one-dimensional Bose gases in shallow optical lattices
We study the decay of superflow via thermally activated phase slips in one-dimensional Bose gases in a shallow optical lattice. By using the Kramers formula, we numerically calculate the nucleation rate of a thermally activated phase slip for various values of the filling factor and flow velocity in the absence of a ha...
1610.08982v3