publicationDate
stringlengths
1
2.79k
title
stringlengths
1
36.5k
abstract
stringlengths
1
37.3k
id
stringlengths
9
47
2017-04-08
Improved Parameter Estimation Techniques for Induction Motors using Hybrid Algorithms
The performance of Newton-Raphson, Levenberg-Marquardt, Damped Newton-Raphson and genetic algorithms are investigated for the estimation of induction motor equivalent circuit parameters from commonly available manufacturer data. A new hybrid algorithm is then proposed that combines the advantages of both descent and na...
1704.02424v1
2017-04-19
Fractional Herglotz Variational Principles with Generalized Caputo Derivatives
We obtain Euler-Lagrange equations, transversality conditions and a Noether-like theorem for Herglotz-type variational problems with Lagrangians depending on generalized fractional derivatives. As an application, we consider a damped harmonic oscillator with time-depending mass and elasticity, and arbitrary memory effe...
1704.05697v1
2017-04-24
Performance Evaluation of the Zero-Multipole Summation Method in Modern Molecular Dynamics Software
We evaluate the practical performance of the zero-multiple summation method (ZMM), a method for approximately calculating electrostatic interactions in molecular dynamics simulations. The performance of the ZMM is compared with that of the smooth particle mesh Ewald method (SPME). Even though the ZMM uses a larger cuto...
1704.07071v1
2017-04-04
Gravity Induced Resonant Emission
The gravitational drift of ions relative to the electrons induces two type of waves in magnetized plasma; ion acoustic (IO) waves and lower hybrid (LH) waves. The IO waves induced by the gravity are damped by electromagnetic (EM) waves leads to the formation of LH waves. For higher wave vector, these LH wave results in...
1704.07225v1
2017-05-12
Controlling Multimode Optomechanical Interactions via Interference
We demonstrate optomechanical interference in a multimode system, in which an optical mode couples to two mechanical modes. A phase-dependent excitation-coupling approach is developed, which enables the observation of constructive and destructive optomechanical interferences. The destructive interference prevents the c...
1705.04722v1
2017-05-18
Band Gap Formation and Tunability in Stretchable Serpentine Interconnects
Serpentine interconnects are highly stretchable and frequently used in flexible electronic systems. In this work, we show that the undulating geometry of the serpentine interconnects will generate phononic band gaps to manipulate elastic wave propagation. The interesting effect of `bands-sticking-together' is observed....
1705.06658v2
2017-05-20
Dispersion and decay of collective modes in neutron star cores
We calculate the frequencies of collective modes of neutrons, protons and electrons in the outer core of neutron stars. The neutrons and protons are treated in a hydrodynamic approximation and the electrons are regarded as collisionless. The coupling of the nucleons to the electrons leads to Landau damping of the colle...
1705.07357v2
2017-05-20
Biosensing using Functionally Graded Piezoelectric MEMS Resonators
Nonlinear dynamics of a two-side electro-statically actuated capacitive micro-beam is studied. The piezoelectric actuation leads to the generation of an axial force along the length of the micro-beam and this is used as a tuning tool to shift the primary resonance of the micro-resonator. The governing equation of motio...
1705.08267v1
2017-05-24
X-Ray Amplification by Stimulated Brillouin Scattering
Plasma-based parametric amplification using stimulated Brillouin scattering offers a route to coherent x-ray pulses orders-of-magnitude more intense than those of the brightest available sources. Brillouin amplification permits amplification of shorter wavelengths with lower pump intensities than Raman amplification, w...
1705.08599v2
2017-05-24
Long-lived mesoscopic entanglement between two damped infinite harmonic chains
We consider two chains, each made of $N$ independent oscillators, immersed in a common thermal bath and study the dynamics of their mutual quantum correlations in the thermodynamic, large-$N$ limit. We show that dissipation and noise due to the presence of the external environment are able to generate collective quantu...
1705.08648v1
2017-05-24
Effect of radiation damping on the Child-Langmuir law in open diodes
We present a microscopic derivation of the space charge limited current for the motion of non-relativistic charged particles inside a parallel vacuum tube diode taking into account the radiation reaction force. We study the space charged limited current for two different limiting cases. Our results reveal that in the l...
1705.09567v2
2017-05-29
Deterministic preparation of highly non-classical macroscopic quantum states
We present a scheme to deterministically prepare non-classical quantum states of a massive mirror including highly non-Gaussian states exhibiting sizeable negativity of the Wigner function. This is achieved by exploiting the non-linear light-matter interaction in an optomechanical cavity by driving the system with opti...
1705.10334v2
2017-06-01
Nonlinear transport by vortex tangles in cuprate high-temperature superconductors
A unified model of vortex tangles is proposed to describe unconventional transport in cuprate high-temperature superconductors, which not only captures the fast vortices scenario at low density, but also predicts a novel mechanism of core-core collisions in dense vortex fluid regime. The theory clarifies the nature of ...
1706.00228v1
2017-06-16
Distributed Estimation of Oscillations in Power Systems: an Extended Kalman Filtering Approach
Online estimation of electromechanical oscillation parameters provides essential information to prevent system instability and blackout and helps to identify event categories and locations. We formulate the problem as a state space model and employ the extended Kalman filter to estimate oscillation frequencies and damp...
1706.05355v1
2017-06-20
Relative and Mean Motions of Multi-Machine Power Systems in Classical Model
It is well-known that in an m-machine power system where each machine is represented by a second-order differential equation, the Jacobian of the system equation contains (m-1) pairs of conjugate eigenvalues and two real eigenvalues, including at least one zero. This letter proves that under the uniform damping conditi...
1706.06226v1
2017-06-25
Influence of qubits' nonradiative decay into a common bath on the transport properties of microwave photons
We consider the influence of nonradiative damping of qubits on the microwave transport of photons, propagating in an open one-dimensional microstrip line. Within the framework of the formalism of a non-Hermitian Hamiltonian we obtained the expressions for the transmission and reflection coefficients for two qubits whic...
1706.08028v2
2017-06-26
Complexity of the Regularized Newton Method
Newton's method for finding an unconstrained minimizer for strictly convex functions, generally speaking, does not converge from any starting point. We introduce and study the damped regularized Newton's method (DRNM). It converges globally for any strictly convex function, which has a minimizer in $R^n$. Locally D...
1706.08483v1
2018-02-02
Energy decay and global solutions for a damped free boundary fluid-elastic structure interface model with variable coefficients in elasticity
We cope with a free boundary fluid-structure interaction model. In the model, the viscous incompressible fluid interacts with elastic body via the common boundary. The motion of the fluid is governed by Navier-Stokes equations while the displacement of elastic structure is described by variable coefficient wave equatio...
1802.00585v2
2018-06-30
Global Well-Posedness and Exponential Stability for Heterogeneous Anisotropic Maxwell's Equations under a Nonlinear Boundary Feedback with Delay
We consider an initial-boundary value problem for the Maxwell's system in a bounded domain with a linear inhomogeneous anisotropic instantaneous material law subject to a nonlinear Silver-Muller-type boundary feedback mechanism incorporating both an instantaneous damping and a time-localized delay effect. By proving th...
1807.00098v2
2018-07-05
Generalized Adiabatic Theorem and Strong-Coupling Limits
We generalize Kato's adiabatic theorem to nonunitary dynamics with an isospectral generator. This enables us to unify two strong-coupling limits: one driven by fast oscillations under a Hamiltonian, and the other driven by strong damping under a Lindbladian. We discuss the case where both mechanisms are present and pro...
1807.02036v2
2018-07-13
Weighted $L^2-L^2$ estimate for wave equation and its applications
In this work we establish a weighted $L^2-L^2$ estimate for inhomogeneous wave equation in 3-D, by introducing a Morawetz multiplier with weight of power $s(1<s<2)$, and then integrating on the light cones and $t$ slice. With this weighted $L^2-L^2$ estimate in hand, we may give a new proof of global existence for smal...
1807.05109v1
2018-07-14
Non-Markovianity through quantum coherence in an all-optical setup
We propose an all-optical experiment to quantify non-Markovianity in an open quantum system through quantum coherence of a single quantum bit. We use an amplitude damping channel implemented by an optical setup with an intense laser beam simulating a single-photon polarization. The optimization over initial states requ...
1807.05378v2
2018-07-17
Energy decay for evolution equations with delay feedbacks
We study abstract linear and nonlinear evolutionary systems with single or multiple delay feedbacks, illustrated by several concrete examples. In particular, we assume that the operator associated with the undelayed part of the system generates an exponentially stable semigroup and that the delay damping coefficients a...
1807.06445v2
2018-07-31
Cooling of the rotation of a nanodiamond via the interaction with the electron spin of the contained NV-center
We propose a way to cool the rotation of a nanodiamond, which contains a NV-center and is levitated by an optical tweezer. Following the rotation of the particle, the NV-center electron spin experiences varying external fields and so leads to spin-rotation coupling. By optically pumping the electrons from a higher en...
1807.11647v1
2018-08-02
Enhanced Attenuation Arising from Lattice Resonances in a Plasma Photonic Crystal
We describe the experimental verification of lattice resonances in two-dimensional photonic crystals constructed from an array of gaseous plasma columns. Enhancements are seen in the extinction of normal incidence transverse electric electromagnetic waves when the localized surface plasmon modes of the plasma columns a...
1808.00610v1
2018-08-10
On the compactness of weak solutions to the Navier-Stokes-Korteweg equations for capillary fluids
In this paper we consider the Navier-Stokes-Korteweg equations for a viscous compressible fluid with capillarity effects in three space dimensions. We prove compactness of finite energy weak solutions for large initial data. In contrast with previous results regarding this system, vacuum regions are allowed in the defi...
1808.03495v2
2018-08-10
Collision quenching in the ultrafast dynamics of plasmonic materials
We explore the nonlinear response of plasmonic materials driven by ultrashort pulses of electromagnetic radiation with temporal duration of few femtoseconds and high peak intensity. By developing the Fokker-Planck-Landau theory of electron collisions, we solve analytically the collisional integral and derive a novel se...
1808.03669v1
2018-08-11
Beam Breakup Mitigation by Ion Mobility in Plasma Acceleration
Moderate ion mobility provides a source of damping in the plasma wakefield acceleration, which may serve as an effective remedy against the transverse instability of the trailing bunch. Ion mobility in the fields of the driving and trailing bunches is taken into account; the related effects are estimated for the FACET-...
1808.03860v2
2018-08-22
Weak convergence of Euler-Maruyama's approximation for SDEs under integrability condition
This work establishes the weak convergence of Euler-Maruyama's approximation for stochastic differential equations (SDEs) with singular drifts under the integrability condition in lieu of the widely used growth condition. This method is based on a skillful application of the dimension-free Harnack inequality. Moreover,...
1808.07250v1
2018-09-30
Dynamic behaviour of a ring coupled boost converter system with passivity-based control
This paper discusses a dispersed generation system of multiple DC/DC converters with DC power sources connected in a ring formulation. Here is presented the analysis of the system based on the stored energy and passivity characteristics of the system. Passivity Based Control (PBC), with its energy-modifying and damping...
1810.00417v1
2018-10-08
Screening in the finite-temperature reduced Hartree-Fock model
We prove the existence of solutions of the reduced Hartree-Fock equations at finite temperature for a periodic crystal with a small defect, and show total screening of the defect charge by the electrons. We also show the convergence of the damped self-consistent field iteration using Kerker preconditioning to remove ch...
1810.03342v2
2018-10-17
A natural 4-parameter family of covariance functions for stationary Gaussian processes
A four-parameter family of covariance functions for stationary Gaussian processes is presented. We call it 2Dsys. It corresponds to the general solution of an autonomous second-order linear stochastic differential equation, thus arises naturally from modelling. It covers underdamped and overdamped systems, so it is pro...
1810.07738v1
2018-10-29
Nonlinear Semi-Classical 3D Quantum Spin
In an effort to provide an alternative method to represent a quantum spin, a precise 3D nonlinear dynamics method is used. A two-sided torque function is created to mimic the unique behavior of the quantum spin. A full 3D representation of the magnetic field of a Stern-Gerlach device was used as in the original experim...
1810.12424v1
2019-01-03
Ultrafast carrier relaxation and its Pauli drag in photo-enhanced melting of solids
Ultrafast light-matter interaction is a powerful tool for the study of solids. Upon laser excitation, carrier multiplication and lattice acceleration beyond thermal velocity can occur, as a result of far-from-equilibrium carrier relaxation. The roles of electron-electron and electron-phonon scatterings are identified b...
1901.00609v1
2019-01-04
Event-triggered damping stabilization of a linear wave equation
The paper addresses the design of an event-triggering mechanism for a partial differential wave equation posed in a bounded domain. The wave equation is supposed to be controlled through a first order time derivative term distributed in the whole domain. Sufficient conditions based on the use of suitable Lyapunov funct...
1901.01009v1
2019-01-18
On Quantum Fields at High Temperature
Revisiting the fast fermion damping rate calculation in a thermalized QED and/or QCD plasma at 4-loop order, focus is put on a peculiar perturbative structure which has no equivalent at zero-temperature. Not surprisingly and in agreement with previous $C^\star$-algebraic analyses, this structure renders the use of ther...
1901.06338v2
2019-01-23
Global well-posedness for the Phan-Thein-Tanner model in critical Besov spaces without damping
In this paper, we mainly investigate the Cauchy problem for the Phan-Thein-Tanner (PTT) model. The PPT model can be viewed as a Navier-Stokes equations couple with a nonlinear transport system. This model is derived from network theory for the polymeric fluid. We study about the global well posedness of the PTT model i...
1901.08515v1
2019-01-27
Breaking optomechanical cooling limit by two drive fields on a membrane-in-middle system
We present a theoretical scheme for ground state cooling of a mechanical resonator in a membrane-in-middle optomechanical system (OMS) driven by two red-detuned drive fields. The details of dynamical evolution of OMS are provided, and the effect of system conditions on cooling results are systematically studied. Most i...
1901.09338v1
2019-04-03
Comparison of semiclassical and quantum models of a two-level atom-cavity QED system in the strong coupling regime
We present a numerical study comparing semiclassical and quantum models of a damped, strongly interacting cavity QED system composed of a single two-level atom interacting with a single quantized cavity mode driven externally by a tunable monochromatic field. We compute the steady state transmission spectrum of the cou...
1904.02270v2
2019-04-04
Comparison between isothermal collision-streaming and finite-difference lattice Boltzmann models
We present here a comparison between collision-streaming and finite-difference lattice Boltzmann (LB) models. This study provides a derivation of useful formulae which help one to properly compare the simulation results obtained with both LB models. We consider three physical problems: the shock wave propagation, the d...
1904.02471v1
2019-04-07
Remarks on decay effects of regularity loss type wave equations with structural damping terms
After GGH model was proposed by M. Ghisi, M. Gobbino and A. Haraux (2016), R. Ikehata and S. Iyota (2018) showed decay estimates for the total energy of solutions to GGH equations uniformly in the initial data. However, their results imply that the total energy is bounded when the initial data belong to the energy spac...
1904.03686v1
2019-04-18
Equilibrium properties and decoherence of an open harmonic oscillator
The equilibrium properties of an open harmonic oscillator are considered in three steps: First the creation and destruction operators are generalized for open dynamics and the creation operator is used to construct coherent states. The second step consists of the introduction of the Heisenberg representation where the ...
1904.08706v2
2019-04-18
Rellich, Gagliardo-Nirenberg, Trudinger and Caffarelli-Kohn-Nirenberg inequalities for Dunkl operators and applications
In this paper we obtain weighted higher order Rellich, weighted Gagliardo-Nirenberg, Trudinger, Caffarelli-Kohn-Nirenberg inequalities and the uncertainty principle for Dunkl operators. Moreover, we introduce an extension of the classical Caffarelli-Kohn-Nirenberg inequalities. Furthermore, we give an application of Ga...
1904.08725v2
2019-04-19
Axi-symmetrization near point vortex solutions for the 2D Euler equation
We prove a definitive theorem on the asymptotic stability of point vortex solutions to the full Euler equation in 2 dimensions. More precisely, we show that a small, Gevrey smooth, and compactly supported perturbation of a point vortex leads to a global solution of the Euler equation in 2D, which converges weakly as $t...
1904.09170v1
2019-04-21
Quantum state preparation for coupled period tripling oscillators
We investigate the quantum transition to a correlated state of coupled oscillators in the regime where they display period tripling in response to a drive at triple the eigenfrequency. Correlations are formed between the discrete oscillation phases of individual oscillators. The evolution toward the ordered state is ac...
1904.09628v1
2019-04-28
Quantum noise in the spin transfer torque effect
Describing the microscopic details of the interaction of magnets and spin-polarized currents is key to achieve control of such systems at the microscopic level. Here we discuss a description based on the Keldysh technique, casting the problem in the language of open quantum systems. We reveal the origin of noise in the...
1904.12372v1
2019-06-03
Magnon-phonon interactions in magnetic insulators
We address the theory of magnon-phonon interactions and compute the corresponding quasi-particle and transport lifetimes in magnetic insulators with focus on yttrium iron garnet at intermediate temperatures from anisotropy- and exchange-mediated magnon-phonon interactions, the latter being derived from the volume depen...
1906.01042v1
2019-06-17
Time discretization of an initial value problem for a simultaneous abstract evolution equation applying to parabolic-hyperbolic phase-field systems
This article deals with a simultaneous abstract evolution equation. This includes a parabolic-hyperbolic phase-field system as an example which consists of a parabolic equation for the relative temperature coupled with a semilinear damped wave equation for the order parameter. Although a time discretization of an initi...
1906.06887v1
2019-06-20
Low-cost ultrasonic distance measurement in a mechanical resonance experiment
We present a low-cost, dual-probe position sensor in a mechanical resonance experiment suitable for deployment in large lab courses with multiple stations. The motion of the two ends of a driven, damped spring oscillator is recorded with US-100 ultrasonic distance sensors and ESP8266 microcontrollers. Sensor lag is com...
1906.08778v1
2019-06-25
Finite-Dimensional Controllers for Robust Regulation of Boundary Control Systems
We study the robust output regulation of linear boundary control systems by constructing extended systems. The extended systems are established based on solving static differential equations under two new conditions. We first consider the abstract setting and present finite-dimensional reduced order controllers. The co...
1906.10345v3
2019-07-06
Angle-resolved broadband ferromagnetic resonance apparatus enabled through a spring-loaded sample mounting manipulator
Broadband ferromagnetic resonance is a useful technique to determine the magnetic anisotropy and study the magnetization dynamics of magnetic thin films. We report a spring-loaded sample loading manipulator for reliable sample mounting and rotation. The manipulator enables maximum signal, enhances system stability and ...
1907.03097v1
2019-07-23
Trees and Islands -- Machine learning approach to nuclear physics
We implement machine learning algorithms to nuclear data. These algorithms are purely data driven and generate models that are capable to capture intricate trends. Gradient boosted trees algorithm is employed to generate a trained model from existing nuclear data, which is used for prediction for data of damping parame...
1907.09764v1
2019-07-31
Multiple Energy Storage Rings
Energy recovery linacs have been studied and developed over a number of decades. In the standard arrangement there is a separate particle source and particle beam dump. In this paper, a new arrangement is explored where the energy recovery linac is used as an energy source in a storage ring which has multiple beam ener...
1907.13461v1
2019-10-07
Quasiclassical nonlinear plasmon resonance in graphene
Electrons in graphene behave like relativistic Dirac particles which can reduce velocity of light by two orders of magnitude in the form of plasmon-polaritons. Here we show how these properties lead to a peculiar nonlinear plasmon response in the quasiclassical regime of terahertz frequencies. On one hand we show how i...
1910.03017v2
2019-10-18
Square-integrable eigenfunctions in quantizing the Bateman oscillator model
In a recent paper [Phys. Lett. A 383 (2019) 2836; arXiv:1906.05121 [quant-ph]], Bagarello, Gargano, and Roccati have claimed that no square-integrable vacuum exists in quantizing the Bateman oscillator model. In this paper, we rebut their claim by actually deriving the square-integrable vacuum eigenfunction using a com...
1910.08271v1
2019-10-25
A damped forward-backward algorithm for stochastic generalized Nash equilibrium seeking
We consider a stochastic generalized Nash equilibrium problem (GNEP) with expected-value cost functions. Inspired by Yi and Pavel (Automatica, 2019), we propose a distributed GNE seeking algorithm by exploiting the forward-backward operator splitting and a suitable preconditioning matrix. Specifically, we apply this me...
1910.11776v2
2019-10-27
Phase slip statistics of a single isolated flux-biased superconducting ring
We describe measurements of the thermally-activated transitions between fluxoid states of a single isolated superconducting ring. We compare these measurements with theoretical predictions in which all of the relevant parameters are determined via independent characterization of the same ring. This no-free-parameters c...
1910.12296v3
2019-10-28
Reply to Comment on "A no-go result for the quantum damped harmonic oscillator"
In a recent paper, \cite{deguchi}, Deguchi and Fujiwara claim that our results in \cite{BGR} are wrong, and compute what they claim is the square integrable vacuum of their annihilation operators. In this brief note, we show that their vacuum is indeed not a vacuum, and we try to explain what is behind their mistake. W...
1910.12561v1
2019-11-30
Robustness Evaluation of the Butterfly Optimization Algorithm on a Control System
In this paper, the Butterfly Optimization Algorithm (BOA) proposed by [1] is adopted to optimize the parameters of a designed Lead-Lad Controller so as to obtain a stabilized control system. Numerical analysis was carried out for BOA on the control problem and the results are compared to those obtained from the well kn...
1912.00185v1
2019-12-05
Blow up for small-amplitude semilinear wave equations with mixed nonlinearities on asymptotically Euclidean manifolds
In this work, we investigate the problem of finite time blow up as well as the upper bound estimates of lifespan for solutions to small-amplitude semilinear wave equations with mixed nonlinearities $a |u_t|^p+b |u|^q$, posed on asymptotically Euclidean manifolds, which is related to both the Strauss conjecture and Glas...
1912.02561v1
2019-12-13
On an existence theory for a fluid-beam problem encompassing possible contacts
In this paper we consider a coupled system of pdes modelling the interaction between a two--dimensional incompressible viscous fluid and a one--dimensional elastic beam located on the upper part of the fluid domain boundary. We design a functional framework to define weak solutions in case of contact between the elasti...
1912.06396v1
2019-12-16
Performance and error modeling of Deutsch's algorithm in IBM Q
The performance of quantum computers today can be studied by analyzing the effect of errors in the result of simple quantum algorithms. The modeling and characterization of these errors is relevant to correct them, for example, with quantum correcting codes. In this article we characterize the error of the five qubits ...
1912.07486v1
2019-12-17
Global cosmic string networks as a function of tension
We investigate the properties of global cosmic string networks as a function of the ratio of string tension to Goldstone-field coupling, and as a function of the Hubble damping strength. Our results show unambiguously that the string density is sensitive to this ratio. We also find that existing semi-analytical (one-sc...
1912.08058v2
2019-12-20
Exact Model Reduction and Fast Forced Response Calculation in High-Dimensional Nonlinear Mechanical Systems
We show how spectral submanifold (SSM) theory can be used to extract forced-response curves, including isolas, without any numerical simulation in high-degree-of-freedom, periodically forced mechanical systems. We use multivariate recurrence relations to construct the SSMs, achieving a major speed-up relative to earlie...
1912.11399v1
2019-12-24
Enstrophy dissipation and vortex thinning for the incompressible 2D Navier-Stokes equations
By direct numerical simulation to the two-dimensional Navier-Stokes equations with small-scale forcing and large-scale damping, Xiao-Wan-Chen-Eyink (2009) found an evidence that inverse energy cascade may proceed with the vortex thinning mechanism. On the other hand, Alexakis-Doering (2006) calculated upper bound of th...
1912.11479v2
2019-12-26
Bifurcation analysis of a density oscillator using two-dimensional hydrodynamic simulation
A density oscillator exhibits limit-cycle oscillations driven by the density difference of the two fluids. We performed two-dimensional hydrodynamic simulations with a simple model, and reproduced the oscillatory flow observed in experiments. As the density difference is increased as a bifurcation parameter, a damped o...
1912.11806v2
2019-12-31
Neutrino evolution and quantum decoherence
Neutrino interactions with an external environment can in influence the neutrino oscillation pattern and the oscillations can be damped as a result of the neutrino quantum decoherence. In particular, the quantum decoherence of neutrino states engendered by the neutrino radiative decay accounting for the nonstandard int...
1912.13311v1
2020-03-02
Optimal transport: discretization and algorithms
This chapter describes techniques for the numerical resolution of optimal transport problems. We will consider several discretizations of these problems, and we will put a strong focus on the mathematical analysis of the algorithms to solve the discretized problems. We will describe in detail the following discretizati...
2003.00855v1
2020-03-03
Preconditioning mixed finite elements for tide models
We describe a fully discrete mixed finite element method for the linearized rotating shallow water model, possibly with damping. While Crank-Nicolson time-stepping conserves energy in the absence of drag or forcing terms and is not subject to a CFL-like stability condition, it requires the inversion of a linear system ...
2003.01632v1
2020-03-12
Geometry-aware Dynamic Movement Primitives
In many robot control problems, factors such as stiffness and damping matrices and manipulability ellipsoids are naturally represented as symmetric positive definite (SPD) matrices, which capture the specific geometric characteristics of those factors. Typical learned skill models such as dynamic movement primitives (D...
2003.06061v1
2020-03-16
Extreme Hawking Radiation
Modeling the collapse of an extreme Reissner-Nordstr\"om (ERN) black hole by solving the corresponding moving mirror model for the trajectory that asymptotically approaches uniform acceleration, we obtain the non-zero beta coefficients for all times. Finite energy is emitted, the radiation spectra is non-thermal (non-s...
2003.07016v1
2020-03-23
Mixed boundary valued problem for linear and nonlinear wave equations in domains with fractal boundaries
The weak well-posedness, with the mixed boundary conditions, of the strongly damped linear wave equation and of the non linear Westervelt equation is proved in the largest natural class of Sobolev admissible non-smooth domains. In the framework of uniform domains in R^2 or R^3 we also validate the approximation of the ...
2003.10134v2
2020-08-02
Partially Coherent Direct Sum Channels
We introduce Partially Coherent Direct Sum (PCDS) quantum channels, as a generalization of the already known Direct Sum quantum channels. We derive necessary and sufficient conditions to identify the subset of those maps which are degradable, and provide a simplified expression for their quantum capacities. Interesting...
2008.00494v4
2020-08-05
Time scales in the thermal dynamics of magnetic dipolar clusters
The collective behavior of thermally active structures offers clues on the emergent degrees of freedom and the physical mechanisms that determine the low energy state of a variety of systems. Here, the thermally active dynamics of magnetic dipoles at square plaquettes is modeled in terms of Brownian oscillators in cont...
2008.01891v2
2020-08-06
Plasmonic nonreciprocity driven by band hybridization in moiré materials
We propose a new current-driven mechanism for achieving significant plasmon dispersion nonreciprocity in systems with narrow, strongly hybridized electron bands. The magnitude of the effect is controlled by the strength of electron-electron interactions $\alpha$, which leads to its particular prominence in moir\'e mate...
2008.02804v1
2022-01-12
Light and microwave driven spin pumping across FeGaB-BiSb interface
3-D topological insulators (TI) with large spin Hall conductivity have emerged as potential candidates for spintronic applications. Here, we report spin to charge conversion in bilayers of amorphous ferromagnet (FM) Fe_{78}Ga_{13}B_{9} (FeGaB) and 3-D TI Bi_{85}Sb_{15} (BiSb) activated by two complementary techniques: ...
2201.04686v1
2024-03-21
Picotesla-sensitivity microcavity optomechanical magnetometry
Cavity optomechanical systems have enabled precision sensing of magnetic fields, by leveraging the optical resonance-enhanced readout and mechanical resonance-enhanced response. Previous studies have successfully achieved scalable and reproducible microcavity optomechanical magnetometry (MCOM) by incorporating Terfenol...
2403.14301v1
2015-08-28
Control of magnetic relaxation by electric-field-induced ferroelectric phase transition and inhomogeneous domain switching
Electric-field modulation of magnetism in strain-mediated multiferroic heterostructures is considered a promising scheme for enabling memory and magnetic microwave devices with ultralow power consumption. However, it is not well understood how electric-field-induced strain influences magnetic relaxation, an important p...
1508.07290v2
2022-01-11
Resonant Precession of Magnetization and Precession -- Induced DC voltages in FeGaB Thin Films
Measurements of frequency dependent ferromagnetic resonance (FMR) and spin pumping driven dc voltage (V_{dc}) are reported for amorphous films of Fe_{78}Ga_{13}B_{9} (FeGaB) alloy to address the phenomenon of self-induced inverse spin Hall effect (ISHE) in plain films of metallic ferromagnets. The V_{dc} signal, which ...
2201.03739v1
2014-11-22
Quantification of the spin-Hall anti-damping torque with a resonance spectrometer
We present a simple technique using a cavity-based resonance spectrometer to quantify the anti-damping torque due to the spin Hall effect. Modification of ferromagnetic resonance is observed as a function of small DC current in sub-mm-wide strips of bilayers, consisting of magnetically soft FeGaB and strong spin-Hall m...
1411.6166v1
2021-12-10
Enhanced Planar Antenna Efficiency Through Magnetic Thin-Films
This work proposes to use magnetic material as the substrate of planar antennas to overcome the platform effect caused by the conducting ground plane. The upper bound of the radiation efficiency of an electric-current-driven low-profile antenna is theoretically derived, which is inversely proportional to the Gilbert da...
2201.04932v1
2017-09-29
Non-local Gilbert damping tensor within the torque-torque correlation model
An essential property of magnetic devices is the relaxation rate in magnetic switching which depends strongly on the damping in the magnetisation dynamics. It was recently measured that damping depends on the magnetic texture and, consequently, is a non-local quantity. The damping enters the Landau-Lifshitz-Gilbert equ...
1709.10365v1
2016-02-23
Experimental Investigation of Temperature-Dependent Gilbert Damping in Permalloy Thin Films
The Gilbert damping of ferromagnetic materials is arguably the most important but least understood phenomenological parameter that dictates real-time magnetization dynamics. Understanding the physical origin of the Gilbert damping is highly relevant to developing future fast switching spintronics devices such as magnet...
1602.07325v1
2019-02-22
Strongly Enhanced Gilbert Damping in 3d Transition Metal Ferromagnet Monolayers in Contact with Topological Insulator Bi2Se3
Engineering Gilbert damping of ferromagnetic metal films is of great importance to exploit and design spintronic devices that are operated with an ultrahigh speed. Based on scattering theory of Gilbert damping, we extend the torque method originally used in studies of magnetocrystalline anisotropy to theoretically dete...
1902.08700v1
2018-08-20
Gilbert damping of [Co/Pd]n/Py multilayer thin films
Understanding the Gilbert damping in exchange-coupled multilayer materials is particularly important to develop future fast switching spintronics devices. Here, we report an experimental investigation of temperature-dependent Gilbert damping in [Co/Pd]n/Py multilayer films of varying the number of Co/Pd repetitions by ...
1808.06515v2
2007-08-24
Enhancement of the Gilbert damping constant due to spin pumping in noncollinear ferromagnet/nonmagnet/ferromagnet trilayer systems
We analyzed the enhancement of the Gilbert damping constant due to spin pumping in non-collinear ferromagnet / non-magnet / ferromagnet trilayer systems. We show that the Gilbert damping constant depends both on the precession angle of the magnetization of the free layer and on the direction of the magntization of the ...
0708.3323v1
2017-06-14
Temperature-dependent Gilbert damping of Co2FeAl thin films with different degree of atomic order
Half-metallicity and low magnetic damping are perpetually sought for in spintronics materials and full Heusler alloys in this respect provide outstanding properties. However, it is challenging to obtain the well-ordered half-metallic phase in as-deposited full Heusler alloys thin films and theory has struggled to estab...
1706.04670v2
2023-11-27
Gilbert damping in two-dimensional metallic anti-ferromagnets
A finite spin life-time of conduction electrons may dominate Gilbert damping of two-dimensional metallic anti-ferromagnets or anti-ferromagnet/metal heterostructures. We investigate the Gilbert damping tensor for a typical low-energy model of a metallic anti-ferromagnet system with honeycomb magnetic lattice and Rashba...
2311.16268v2
2008-07-31
Scattering Theory of Gilbert Damping
The magnetization dynamics of a single domain ferromagnet in contact with a thermal bath is studied by scattering theory. We recover the Landau-Liftshitz-Gilbert equation and express the effective fields and Gilbert damping tensor in terms of the scattering matrix. Dissipation of magnetic energy equals energy current p...
0807.5009v1
2024-01-18
Real-space nonlocal Gilbert damping from exchange torque correlation applied to bulk ferromagnets and their surfaces
In this work we present an ab initio scheme based on linear response theory of exchange torque correlation, implemented into the real-space Korringa-Kohn-Rostoker (RS-KKR) framework to calculate diagonal elements of the atomic-site-dependent intrinsic Gilbert damping tensor. The method is first applied to bcc iron and ...
2401.09938v2
2007-06-12
Gilbert and Landau-Lifshitz damping in the presense of spin-torque
A recent article by Stiles et al. (cond-mat/0702020) argued in favor of the Landau-Lifshitz damping term in the micromagnetic equations of motion over that of the more commonly accepted Gilbert damping form. Much of their argument revolved around spin-torque driven domain wall motion in narrow magnetic wires, since the...
0706.1736v1
2008-04-04
Inhomogeneous Gilbert damping from impurities and electron-electron interactions
We present a unified theory of magnetic damping in itinerant electron ferromagnets at order $q^2$ including electron-electron interactions and disorder scattering. We show that the Gilbert damping coefficient can be expressed in terms of the spin conductivity, leading to a Matthiessen-type formula in which disorder and...
0804.0820v2
2006-12-01
Gilbert damping and spin Coulomb drag in a magnetized electron liquid with spin-orbit interaction
We present a microscopic calculation of the Gilbert damping constant for the magnetization of a two-dimensional spin-polarized electron liquid in the presence of intrinsic spin-orbit interaction. First we show that the Gilbert constant can be expressed in terms of the auto-correlation function of the spin-orbit induced...
0612015v1
2021-01-07
Mechanisms behind large Gilbert damping anisotropies
A method with which to calculate the Gilbert damping parameter from a real-space electronic structure method is reported here. The anisotropy of the Gilbert damping with respect to the magnetic moment direction and local chemical environment is calculated for bulk and surfaces of Fe$_{50}$Co$_{50}$ alloys from first pr...
2101.02794v2
2018-08-13
Gilbert damping phenomenology for two-sublattice magnets
We present a systematic phenomenological description of Gilbert damping in two-sublattice magnets. Our theory covers the full range of materials from ferro- via ferri- to antiferromagnets. Following a Rayleigh dissipation functional approach within a Lagrangian classical field formulation, the theory captures intra- as...
1808.04385v2
2021-07-02
Anomalous Gilbert Damping and Duffing Features of the SFS {\boldmath $\varphi_0$} Josephson Junction
We demonstrate unusual features of phase dynamics, IV-characteristics and magnetization dynamics of the $\varphi_0$ Josephson junction at small values of spin-orbit interaction, ratio of Josephson to magnetic energy and Gilbert damping. In particular, an anomalous shift of the ferromagnetic resonance frequency with an ...
2107.00982v3
2023-03-07
Electrically tunable Gilbert damping in van der Waals heterostructures of two-dimensional ferromagnetic metals and ferroelectrics
Tuning the Gilbert damping of ferromagnetic (FM) metals via a nonvolatile way is of importance to exploit and design next-generation novel spintronic devices. Through systematical first-principles calculations, we study the magnetic properties of the van der Waals heterostructure of two-dimensional FM metal CrTe2 and f...
2303.03852v1
2015-08-28
The inviscid limit for the Landau-Lifshitz-Gilbert equation in the critical Besov space
We prove that in dimensions three and higher the Landau-Lifshitz- Gilbert equation with small initial data in the critical Besov space is globally wellposed in a uniform way with respect to the Gilbert damping parameter. Then we show that the global solution converges to that of the Schrodinger maps in the natural spa...
1508.07118v3
2023-09-20
Evaluating Gilbert Damping in Magnetic Insulators from First Principles
Magnetic damping has a significant impact on the performance of various magnetic and spintronic devices, making it a long-standing focus of research. The strength of magnetic damping is usually quantified by the Gilbert damping constant in the Landau-Lifshitz-Gilbert equation. Here we propose a first-principles based a...
2309.11152v1
2019-06-25
Conductivity-Like Gilbert Damping due to Intraband Scattering in Epitaxial Iron
Confirming the origin of Gilbert damping by experiment has remained a challenge for many decades, even for simple ferromagnetic metals. In this Letter, we experimentally identify Gilbert damping that increases with decreasing electronic scattering in epitaxial thin films of pure Fe. This observation of conductivity-lik...
1906.10326v2