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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
2016-09-01
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
2016-10-03
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
2016-10-14
Nambu mechanics for stochastic magnetization dynamics
The Landau-Lifshitz-Gilbert (LLG) equation describes the dynamics of a damped magnetization vector that can be understood as a generalization of Larmor spin precession. The LLG equation cannot be deduced from the Hamiltonian framework, by introducing a coupling to a usual bath, but requires the introduction of addition...
1610.04598v2
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
2016-10-28
Damping-free collective oscillations of a driven two-component Bose gas in optical lattices
We explore quantum many-body physics of a driven Bose-Einstein condensate in optical lattices. The laser field induces a gap in the generalized Bogoliubov spectrum proportional to the effective Rabi frequency. The lowest lying modes in a driven condensate are characterized by zero group velocity and non-zero current. T...
1610.09076v5
2016-11-02
An extension of Bakhvalov's theorem for systems of conservation laws with damping
For $2\X2$ systems of conservation laws satisfying Bakhvalov conditions, we present a class of damping terms that still yield the existence of global solutions with periodic initial data of possibly large bounded total variation per period. We also address the question of the decay of the periodic solution. As applicat...
1611.00698v1
2016-11-15
The damped stochastic wave equation on p.c.f. fractals
A p.c.f. fractal with a regular harmonic structure admits an associated Dirichlet form, which is itself associated with a Laplacian. This Laplacian enables us to give an analogue of the damped stochastic wave equation on the fractal. We show that a unique function-valued solution exists, which has an explicit formulati...
1611.04874v3
2016-11-29
Phase mixing importance for both Landau instability and damping
We discuss the self-consistent dynamics of plasmas by means of hamiltonian formalism for a system of $N$ near-resonant electrons interacting with a single Langmuir wave. The connection with the Vlasov description is revisited through the numerical calculation of the van Kampen-like eigenfrequencies of the linearized dy...
1611.09596v3
2016-11-29
Dark matter annihilation and jet quenching phenomena in the early universe
Dark-matter particles like neutralinos should decouple from the hot cosmic plasma at temperatures of about 40 GeV. Later they can annihilate each other into standard-model particles, which are injected into the dense primordial plasma and quickly loose energy. This process is similar to jet quenching in ultrarelativist...
1611.09662v1
2016-11-30
Perspective on the cosmic-ray electron spectrum above TeV
The AMS-02 has measured the cosmic ray electron (plus positron) spectrum up to ~TeV with an unprecedent precision. The spectrum can be well described by a power law without any obvious features above 10 GeV. The satellite instrument Dark Matter Particle Explorer (DAMPE), which was launched a year ago, will measure the ...
1611.10292v1
2016-12-01
Field- and damping-like spin-transfer torque in magnetic multilayers
We investigate the spin-transfer torque in a magnetic multilayer structure by means of a spin-diffusion model. The torque in the considered system, consisting of two magnetic layers separated by a conducting layer, is caused by a perpendicular-to-plane current. We compute the strength of the field-like and the damping-...
1612.00194v1
2016-12-04
Vector Approximate Message Passing for the Generalized Linear Model
The generalized linear model (GLM), where a random vector $\boldsymbol{x}$ is observed through a noisy, possibly nonlinear, function of a linear transform output $\boldsymbol{z}=\boldsymbol{Ax}$, arises in a range of applications such as robust regression, binary classification, quantized compressed sensing, phase retr...
1612.01186v1
2016-12-06
Quantum Dynamics of Skyrmions in Chiral Magnets
We study the quantum propagation of a Skyrmion in chiral magnetic insulators by generalizing the micromagnetic equations of motion to a finite-temperature path integral formalism, using field theoretic tools. Promoting the center of the Skyrmion to a dynamic quantity, the fluctuations around the Skyrmionic configuratio...
1612.01885v2
2016-12-06
Increased low-temperature damping in yttrium iron garnet thin films
We report measurements of the frequency and temperature dependence of ferromagnetic resonance (FMR) for a 15-nm-thick yttrium iron garnet (YIG) film grown by off-axis sputtering. Although the FMR linewidth is narrow at room temperature (corresponding to a damping coefficient $\alpha$ = (9.0 $\pm$ 0.2) $\times 10^{-4}$)...
1612.01954v1
2016-12-09
Slow motion for one-dimensional nonlinear damped hyperbolic Allen-Cahn systems
We consider a nonlinear damped hyperbolic reaction-diffusion system in a bounded interval of the real line with homogeneous Neumann boundary conditions and we study the metastable dynamics of the solutions. Using an "energy approach" introduced by Bronsard and Kohn [CPAM 1990] to study slow motion for Allen-Cahn equati...
1612.03203v5
2016-12-18
Entropically Damped Artificial Compressibility for SPH
In this paper, the Entropically Damped Artificial Compressibility (EDAC) formulation of Clausen (2013) is used in the context of the Smoothed Particle Hydrodynamics (SPH) method for the simulation of incompressible fluids. Traditionally, weakly-compressible SPH (WCSPH) formulations have employed artificial compressibli...
1612.05901v2
2016-12-19
Kinetic-simulation study of propagation of Langmuir-like ionic waves in dusty plasma
The propagation of ionic perturbations in a dusty plasma is considered through a three-species kinetic simulation approach, in which the temporal evolution of all three elements i.e. electrons, ions and dust particles are followed based on the Vlasov equation coupled with the Poisson equation. Two cases are focused upo...
1612.06182v1
2016-12-21
Environment generated quantum correlations in bipartite qubit-qutrit systems
The dynamics of entanglement and quantum discord for qubit-qutrit systems are studied in the presence of phase damping and amplitude damping noises. Both one way and two couplings of the marginal systems with the environments are considered. Entanglement sudden death is unavoidable under any setup, however, the require...
1612.06981v1
2016-12-28
Stretching and Kibble scaling regimes for Hubble-damped defect networks
The cosmological evolution of topological defect networks can broadly be divided into two stages. At early times they are friction-dominated due to particle scattering and therefore non-relativistic, and may either be conformally stretched or evolve in the Kibble regime. At late times they are relativistic and evolve i...
1612.08863v1
2016-12-29
Laser Pulse Compression Using Magnetized Plasmas
Proposals to reach the next generation of laser intensities through Raman or Brillouin backscattering have centered on optical frequencies. Higher frequencies are beyond the range of such methods mainly due to the wave damping that accompanies the higher density plasmas necessary for compressing higher frequency lasers...
1612.09214v1
2017-01-05
Liquid-like thermal conduction in a crystalline solid
A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations. Here, we report that the crystalline solid AgCrSe2 has liquid-like thermal conduction. In this compound, Ag atoms exhibit a dynamic duality that they are exclusively involved in intense lo...
1701.01192v1
2017-01-09
Oscillations and damping in the fractional Maxwell materials
This paper examines the oscillatory behaviour of complex viscoelastic systems with power law-like relaxation behaviour. Specifically, we use the fractional Maxwell model, consisting of a spring and fractional dashpot in series, which produces a power-law creep behaviour and a relaxation law following the Mittag-Leffler...
1701.02155v2
2017-01-11
Localization in finite asymmetric vibro-impact chains
We explore the dynamics of strongly localized periodic solutions (discrete solitons, or discrete breathers) in a finite one-dimensional chain of asymmetric vibro-impact oscillators. The model involves a parabolic on-site potential with asymmetric rigid constraints (the displacement domain of each particle is finite), a...
1701.03055v1
2017-01-11
The Cauchy problem for the Landau-Lifshitz-Gilbert equation in BMO and self-similar solutions
We prove a global well-posedness result for the Landau-Lifshitz equation with Gilbert damping provided that the BMO semi-norm of the initial data is small. As a consequence, we deduce the existence of self-similar solutions in any dimension. In the one-dimensional case, we characterize the self-similar solutions associ...
1701.03083v2
2017-01-13
Characterizing Fluid and Kinetic Instabilities using Field-Particle Correlations on Single-Point Time Series
A recently proposed technique correlating electric fields and particle velocity distributions is applied to single-point time series extracted from linearly unstable, electrostatic numerical simulations. The form of the correlation, which measures the transfer of phase-space energy density between the electric field an...
1701.03687v1
2017-01-17
Backward Raman Amplification in the Long-wavelength Infrared
The wealth of work in backward Raman amplification in plasma has focused on the extreme intensity limit, however backward Raman amplification may also provide an effective and practical mechanism for generating intense, broad bandwidth, long-wavelength infrared radiation (LWIR). An electromagnetic simulation coupled wi...
1701.04879v2
2017-01-27
Structural scale $q-$derivative and the LLG-Equation in a scenario with fractionality
In the present contribution, we study the Landau-Lifshitz-Gilbert equation with two versions of structural derivatives recently proposed: the scale $q-$derivative in the non-extensive statistical mechanics and the axiomatic metric derivative, which presents Mittag-Leffler functions as eigenfunctions. The use of structu...
1701.08076v2
2017-01-31
Lack of correlation between the spin mixing conductance and the ISHE-generated voltages in CoFeB/Pt,Ta bilayers
We investigate spin pumping phenomena in polycrystalline CoFeB/Pt and CoFeB/Ta bilayers and the correlation between the effective spin mixing conductance $g^{\uparrow\downarrow}_{\rm eff}$ and the obtained voltages generated by the spin-to-charge current conversion via the inverse spin Hall effect in the Pt and Ta laye...
1701.09110v1
2017-02-14
Calibrating damping rates with LEGACY linewidths
Linear damping rates of radial oscillation modes in selected $Kepler$ stars are estimated with the help of a nonadiabatic stability analysis. The convective fluxes are obtained from a nonlocal, time-dependent convection model. The mixing-length parameter is calibrated to the surface-convection-zone depth of a stellar m...
1702.04251v1
2017-02-20
Resonant Scattering Characteristics of Homogeneous Dielectric Sphere
In the present article the classical problem of electromagnetic scattering by a single homogeneous sphere is revisited. Main focus is the study of the scattering behavior as a function of the material contrast and the size parameters for all electric and magnetic resonances of a dielectric sphere. Specifically, the Pad...
1702.05883v1
2017-02-22
A Retrofitting-based Supplementary Controller Design for Enhancing Damping Performance of Wind Power Systems
In this paper we address the growing concerns of wind power integration from the perspective of power system dynamics and stability. We propose a new retrofit control technique where an additional controller is designed at the doubly-fed induction generator site inside the wind power plant. This controller cancels the ...
1702.06695v1
2017-02-23
Plasmon modes of bilayer molybdenum disulfide: A density functional study
We explore the collective electronic excitations of bilayer molybdenum disulfide (MoS$_2$) using the density functional theory together with the random phase approximation. The many-body dielectric function and electron energy-loss spectra are calculated using an {\it ab initio} based model involving material-realistic...
1702.07170v2
2017-02-25
Low-energy photoelectron transmission through aerosol overlayers
The transmission of low-energy (<1.8eV) photoelectrons through the shell of core-shell aerosol particles is studied for liquid squalane, squalene, and DEHS shells. The photoelectrons are exclusively formed in the core of the particles by two-photon ionization. The total photoelectron yield recorded as a function of she...
1702.07865v1
2017-02-26
Magnon-photon coupling in antiferromagnets
Magnon-photon coupling in antiferromagnets has many attractive features that do not exist in ferro- or ferrimagnets. We show quantum-mechanically that, in the absence of an external field, one of the two degenerated spin wave bands couples with photons while the other does not. The photon mode anticrosses with the coup...
1702.07977v1
2017-03-03
Global behaviour of bistable solutions for hyperbolic gradient systems in one unbounded spatial dimension
This paper is concerned with damped hyperbolic gradient systems of the form \[ \alpha u_{tt} + u_t = -\nabla V(u) + u_{xx}\,, \] where the spatial domain is the whole real line, the state variable $u$ is multidimensional, $\alpha$ is a positive quantity, and the potential $V$ is coercive at infinity. For such systems, ...
1703.01221v2
2017-03-06
Polynomial Stabilization of Solutions to a Class of Damped Wave Equations
We consider a class of wave equations of the type $\partial_{tt} u + Lu + B\partial_{t} u = 0$, with a self-adjoint operator $L$, and various types of local damping represented by $B$. By establishing appropriate and raher precise estimates on the resolvent of an associated operator $A$ on the imaginary axis of ${{\Bbb...
1703.01735v1
2017-03-20
A quantum correlated twin atom laser from a Bose-Hubbard system
We propose and evaluate a method to construct a quantum correlated twin atom laser using a pumped and damped Bose-Hubbard inline trimer which can operate in a stationary regime. With pumping via a source condensate filling the middle well and damping using either an electron beam or optical means at the two end wells, ...
1703.06607v2
2017-03-20
Non-universal velocity probability densities in two-dimensional turbulence: the effect of large-scale dissipation
We show that some statistical properties of forced two-dimensional turbulence have an important sensitivity to the form of large-scale dissipation which is required to damp the inverse cascade. We consider three models of large-scale dissipation: linear "Ekman" drag, non-linear quadratic drag, and scale selective hypo-...
1703.07000v1
2017-03-21
Numerical Range and Quadratic Numerical Range for Damped Systems
We prove new enclosures for the spectrum of non-selfadjoint operator matrices associated with second order linear differential equations $\ddot{z}(t) + D \dot{z} (t) + A_0 z(t) = 0$ in a Hilbert space. Our main tool is the quadratic numerical range for which we establish the spectral inclusion property under weak assum...
1703.07447v1
2017-03-22
Kinetic simulations of ladder climbing by electron plasma waves
The energy of plasma waves can be moved up and down the spectrum using chirped modulations of plasma parameters, which can be driven by external fields. Depending on whether the wave spectrum is discrete (bounded plasma) or continuous (boundless plasma), this phenomenon is called ladder climbing (LC) or autoresonant ac...
1703.07694v1
2017-04-03
Sensing Coherent Phonons with Two-photon Interference
Detecting coherent phonons pose different challenges compared to coherent photons due to the much stronger interaction between phonons and matter. This is especially true for high frequency heat carrying phonons, which are intrinsic lattice vibrations experiencing many decoherence events with the environment, and are t...
1704.00446v1
2017-04-03
Simulating spin-boson models with trapped ions
We propose a method to simulate the dynamics of spin-boson models with small crystals of trapped ions where the electronic degree of freedom of one ion is used to encode the spin while the collective vibrational degrees of freedom are employed to form an effective harmonic environment. The key idea of our approach is t...
1704.00629v1
2017-04-07
Coherent-induced state ordering with fixed mixedness
In this paper, we study coherence-induced state ordering with Tsallis relative entropy of coherence, relative entropy of coherence and $l_{1}$ norm of coherence. Firstly, we show that these measures give the same ordering for single-qubit states with a fixed mixedness or a fixed length along the direction $\sigma_{z}$....
1704.02244v1
2017-04-13
A possible connection between the spin temperature of damped Lyman-alpha absorption systems and star formation history
We present a comprehensive analysis of the spin temperature/covering factor degeneracy, T/f, in damped Lyman-alpha absorption systems. By normalising the upper limits and including these via a survival analysis, there is, as previously claimed, an apparent increase in T/f with redshift at z > 1. However, when we accoun...
1704.04294v2
2017-04-17
Magnetic field line random walk in two-dimensional dynamical turbulence
The field line random walk (FLRW) of magnetic turbulence is one of the important topics in plasma physics and astrophysics. In this article by using the field line tracing method mean square displacements (MSD) of FLRW is calculated in all possible length scales for pure two-dimensional turbulence with damping dynamica...
1704.05059v3
2017-04-19
Quantum simulation of quantum channels in nuclear magnetic resonance
We propose and experimentally demonstrate an efficient framework for the quantum simulation of quantum channels in NMR. Our approach relies on the suitable decomposition of non-unitary operators in a linear combination of $d$ unitary ones, which can be then experimentally implemented with the assistance of a number of ...
1704.05593v2
2017-04-24
Beating the Classical Limits of Information Transmission using a Quantum Decoder
Encoding schemes and error-correcting codes are widely used in information technology to improve the reliability of data transmission over real-world communication channels. Quantum information protocols can further enhance the performance in data transmission by encoding a message in quantum states, however, most prop...
1704.07036v2
2017-04-24
Quasilinear diffusion coefficients in a finite Larmor radius expansion for ion cyclotron heated plasmas
In this paper, a reduced model of quasilinear diffusion by a small Larmor radius approximation is derived to couple the Maxwell's equations and the Fokker-Planck equation self-consistently for ion cyclotron range of frequency waves in a tokamak. The reduced model ensures the important properties of the full model by Ke...
1704.07283v1
2017-04-27
Chirality-induced Antisymmetry in Magnetic Domain-Wall Speed
In chiral magnetic materials, numerous intriguing phenomena such as built in chiral magnetic domain walls (DWs) and skyrmions are generated by the Dzyaloshinskii Moriya interaction (DMI). The DMI also results in asymmetric DW speed under in plane magnetic field, which provides a useful scheme to measure the DMI strengt...
1704.08751v1
2017-05-04
Phase-space mixing in dynamically unstable, integrable few-mode quantum systems
Quenches in isolated quantum systems are currently a subject of intense study. Here, we consider quantum few-mode systems that are integrable in their classical mean-field limit and become dynamically unstable after a quench of a system parameter. Specifically, we study a Bose-Einstein condensate (BEC) in a double-well...
1705.01702v1
2017-05-11
Quantum Correlations and Bell Inequality Violation under Decoherence
Quantum Correlations are studied extensively in quantum information domain. Entanglement Measures and Quantum Discord are good examples of these actively studied correlations. Detection of violation in Bell inequalities is also a widely active area in quantum information theory world. In this work, we revisit the probl...
1705.03882v2
2017-05-18
Local and global existence of solutions to a strongly damped wave equation of the $p$-Laplacian type
This article focuses on a quasilinear wave equation of $p$-Laplacian type: $$ u_{tt} - \Delta_p u - \Delta u_t=0$$ in a bounded domain $\Omega\subset\mathbb{R}^3$ with a sufficiently smooth boundary $\Gamma=\partial\Omega$ subject to a generalized Robin boundary condition featuring boundary damping and a nonlinear sour...
1705.06696v2
2017-05-23
Unifying description of the damping regimes of a stochastic particle in a periodic potential
We analyze the classical problem of the stochastic dynamics of a particle confined in a periodic potential, through the so called Il'in and Khasminskii model, with a novel semi-analytical approach. Our approach gives access to the transient and the asymptotic dynamics in all damping regimes, which are difficult to inve...
1705.08083v2
2017-05-27
Experimental Observation of Electron-Acoustic Wave Propagation in Laboratory Plasma
In the field of fundamental plasma waves, direct observation of electron-acoustic wave (EAW) propagation in laboratory plasmas remains a challenging problem, mainly because of heavy damping. In the MaPLE device, the wave is observed and seen to propagate with phase velocity $\sim1.8$ times the electron thermal velocity...
1705.09806v1
2017-06-08
Superconductivity around nematic quantum critical point in two-dimensional metals
We study the properties of $s$-wave superconductivity induced around a nematic quantum critical point in two-dimensional metals. The strong Landau damping and the Cooper pairing between incoherent fermions have dramatic mutual influence on each other, and hence should be treated on an equal footing. This problem is add...
1706.02583v2
2017-06-16
Simulation of non-Pauli Channels
We consider the simulation of a quantum channel by two parties who share a resource state and may apply local operations assisted by classical communication (LOCC). One specific type of such LOCC is standard teleportation, which is however limited to the simulation of Pauli channels. Here we show how we can easily enla...
1706.05384v2
2017-06-17
\emph{Ab initio} calculation of spin-orbit coupling for NV center in diamond exhibiting dynamic Jahn-Teller effect
Point defects in solids may realize solid state quantum bits. The spin-orbit coupling in these point defects plays a key role in the magneto-optical properties that determine the conditions of quantum bit operation. However, experimental data and methods do not directly yield this highly important data, particularly, f...
1706.05523v2
2017-06-20
Decoherence induced spin squeezing signatures in Greenberger-Horne-Zeilinger and W states
We reckon the behaviour of spin squeezing in tripartite unsqueezed maximally entangled Green- berger-Horne-Zeilinger (GHZ) and W states under various decoherence channels with Kitagawa- Ueda (KU) criteria. In order to search spin squeezing sudden death (SSSD) and signatures of spin squeezing production we use bit flip,...
1706.06273v2
2017-06-22
Adaptive recurrence quantum entanglement distillation for two-Kraus-operator channels
Quantum entanglement serves as a valuable resource for many important quantum operations. A pair of entangled qubits can be shared between two agents by first preparing a maximally entangled qubit pair at one agent, and then sending one of the qubits to the other agent through a quantum channel. In this process, the de...
1706.07461v1
2017-06-26
Landau Damping of Beam Instabilities by Electron Lenses
Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers and use of chromatic effects, become less effe...
1706.08477v1
2017-07-01
Amending entanglement-breaking channels via intermediate unitary operations
We report a bulk optics experiment demonstrating the possibility of restoring the entanglement distribution through noisy quantum channels by inserting a suitable unitary operation (filter) in the middle of the transmission process. We focus on two relevant classes of single-qubit channels consisting in repeated applic...
1707.00161v1
2017-06-30
Damped oscillations of the energy of a bosonic bath due to spectral gaps and special initial correlations
The energy of the bosonic bath and the flow of quantum information are analyzed over short and long times in local dephasing channels for special correlated or factorized initial conditions, respectively, which involve thermal states. The continuous distribution of frequency modes of the bosonic bath exhibits a spectra...
1707.00604v1
2017-07-11
Andreev reflection assisted lasing in an electromagnetic resonator coupled to a hybrid-quantum-dot
A single mode electromagnetic resonator coupled to a two-level hybrid-quantum-dot(hQD) is studied theoretically as a laser(maser), when the hQD is driven out of equilibrium with external applied d.c. bias voltage. Using the formalism of the non-equilibrium Green's functions for the hQD and the semi-classical laser equa...
1707.03219v2
2017-07-13
The sharp estimate of the lifespan for the semilinear wave equation with time-dependent damping
We consider the following semilinear wave equation with time-dependent damping. \begin{align} \tag{NLDW} \left\{ \begin{array}{ll} \partial_t^2 u - \Delta u + b(t)\partial_t u = |u|^{p}, & (t,x) \in [0,T) \times \mathbb{R}^n, \\ u(0,x)=\varepsilon u_0(x), u_t(0,x)=\varepsilon u_1(x), & x \in \mathbb{R}^n, \end{array} \...
1707.03950v1
2017-07-17
Candidate dust structures for starlight polarization
Rotation damping and alignment are discussed as prerequisites for polarization power. An expression is derived from first principles, for the damping time of the rotation of a particle in a magnetic field, under the Faraday braking torque, provided its electrical properties are known. This makes it possible to describe...
1707.05247v1
2017-07-21
Quasinormal ringing of black holes in Einstein aether theory
The gravitational consequence of local Lorentz violation (LV) should show itself in derivation of the characteristic quasinormal ringing of black hole mergers from their general relativity case. In this paper, we study quasinormal modes (QNMs) of the scalar and electromagnetic field perturbations to Einstein aether bla...
1707.06747v2
2017-07-24
Self-concordant inclusions: A unified framework for path-following generalized Newton-type algorithms
We study a class of monotone inclusions called "self-concordant inclusion" which covers three fundamental convex optimization formulations as special cases. We develop a new generalized Newton-type framework to solve this inclusion. Our framework subsumes three schemes: full-step, damped-step and path-following methods...
1707.07403v1
2017-07-28
Finding stability domains and escape rates in kicked Hamiltonians
We use an effective Hamiltonian to characterize particle dynamics and find escape rates in a periodically kicked Hamiltonian. We study a model of particles in storage rings that is described by a chaotic symplectic map. Ignoring the resonances, the dynamics typically has a finite region in phase space where it is stabl...
1707.09336v1
2017-07-29
Empirical Bayes approaches to PageRank type algorithms for rating scientific journals
Following criticisms against the journal Impact Factor, new journal influence scores have been developed such as the Eigenfactor or the Prestige Scimago Journal Rank. They are based on PageRank type algorithms on the cross-citations transition matrix of the citing-cited network. The PageRank algorithm performs a smooth...
1707.09508v2
2017-08-09
Stable and unstable roots of ion temperature gradient driven mode using curvature modified plasma dispersion functions
Basic, local kinetic theory of ion temperature gradient driven (ITG) mode, with adiabatic electrons is reconsidered. Standard unstable, purely oscillating as well as damped solutions of the local dispersion relation are obtained using a bracketing technique that uses the argument principle. This method requires computi...
1708.03026v1
2017-08-13
Observation of Spin Superfluidity in a Bose Gas Mixture
The spin dynamics of a harmonically trapped Bose-Einstein condensed binary mixture of sodium atoms is experimentally investigated at finite temperature. In the collisional regime the motion of the thermal component is shown to be damped because of spin drag, while the two condensates exhibit a counter flow oscillation ...
1708.03923v2
2017-08-16
Multi-component plasmons in monolayer MoS$_2$ with circularly polarized optical pumping
By making use of circularly polarized light and electrostatic gating, monolayer molybdenum disulfide (ML-MoS$_2$) can form a platform supporting multiple types of charge carriers. They can be discriminated by their spin, valley index or whether they're electrons or holes. We investigate the collective properties of tho...
1708.04940v1
2017-08-17
Viscous forces and bulk viscoelasticity near jamming
When weakly jammed packings of soft, viscous, non-Brownian spheres are probed mechanically, they respond with a complex admixture of elastic and viscous effects. While many of these effects are understood for specific, approximate models of the particles' interactions, there are a number of proposed force laws in the l...
1708.05241v2
2017-08-21
Diverging, but negligible power at Carnot efficiency: theory and experiment
We discuss the possibility of reaching the Carnot efficiency by heat engines (HEs) out of quasi-static conditions at nonzero power output. We focus on several models widely used to describe the performance of actual HEs. These models comprise quantum thermoelectric devices, linear irreversible HEs, minimally nonlinear ...
1708.06261v4
2017-08-24
The influence of small-scale magnetic field on the evolution of inclination angle and precession damping in the framework of 3-component model of neutron star
The evolution of inclination angle and precession damping of radio pulsars is considered. It is assumed that the neutron star consists of 3 "freely" rotating components: the crust and two core components, one of which contains pinned superfluid vortices. We suppose that each component rotates as a rigid body. Also the ...
1708.07505v1
2017-08-25
On the ultimate energy bound of solutions to some forced second order evolution equations with a general nonlinear damping operator
Under suitable growth and coercivity conditions on the nonlinear damping operator $g$ which ensure non-resonance, we estimate the ultimate bound of the energy of the general solution to the equation $\ddot{u}(t) + Au(t) + g(\dot{u}(t))=h(t),\quad t\in\mathbb{R}^+ ,$ where $A$ is a positive selfadjoint operator on a Hil...
1708.07639v1
2017-08-25
On annihilation of the relativistic electron vortex pair in collisionless plasmas
In contrast to hydrodynamic vortices, vortices in plasma contain an electric current circulating around the center of the vortex, which generates a magnetic field localized inside. Using computer simulations, we demonstrate that the magnetic field associated with the vortex gives rise to a mechanism of dissipation of t...
1708.07803v2
2017-08-30
Finite-temperature behavior of the Bose polaron
We consider a mobile impurity immersed in a Bose gas at finite temperature. Using perturbation theory valid for weak coupling between the impurity and the bosons, we derive analytical results for the energy and damping of the impurity for low and high temperatures, as well as for temperatures close to the critical temp...
1708.09172v2
2017-09-01
Quantum reservoir engineering through quadratic optomechanical interaction in the reversed dissipation regime
We explore the electromagnetic field coupled to a mechanical resonator via quadratic optomechanical interaction in the reversed dissipation regime where the mechanical damping rate is much larger than the cavity field dissipation rate. It is shown that in this regime, the cavity field effectively acquires an additional...
1709.00279v1
2017-09-12
Green's function formalism for spin transport in metal-insulator-metal heterostructures
We develop a Green's function formalism for spin transport through heterostructures that contain metallic leads and insulating ferromagnets. While this formalism in principle allows for the inclusion of various magnonic interactions, we focus on Gilbert damping. As an application, we consider ballistic spin transport b...
1709.03775v1
2017-09-13
Life-span of solutions to semilinear wave equation with time-dependent critical damping for specially localized initial data
This paper is concerned with the blowup phenomena for initial value problem of semilinear wave equation with critical time-dependent damping term (DW). The result is the sharp upper bound of lifespan of solution with respect to the small parameter $\ep$ when $p_F(N)\leq p\leq p_0(N+\mu)$, where $p_F(N)$ denotes the Fuj...
1709.04406v1
2017-09-18
Optimal Energy Growth in Current Sheets
In this paper, we investigate the possibility of transient growth in the linear perturbation of current sheets. The resistive magnetohydrodynamic (MHD) operator for a background field consisting of a current sheet is non-normal, meaning that associated eigenvalues and eigenmodes can be very sensitive to perturbation. I...
1709.05858v1
2017-09-20
Spin-rotation mode in a quantum Hall ferromagnet
A spin-rotation mode emerging in a quantum Hall ferromagnet due to laser pulse excitation is studied. This state, macroscopically representing a rotation of the entire electron spin-system to a certain angle, is not microscopically equivalent to a coherent turn of all spins as a single-whole and is presented in the for...
1709.06811v2
2017-09-22
Muon spin rotation study of the topological superconductor SrxBi2Se3
We report transverse-field (TF) muon spin rotation experiments on single crystals of the topological superconductor Sr$_x$Bi$_2$Se$_3$ with nominal concentrations $x=0.15$ and $0.18$ ($T_c \sim 3$ K). The TF spectra ($B= 10$ mT), measured after cooling to below $T_c$ in field, did not show any additional damping of the...
1709.07547v1
2017-09-22
Slowly damped quasinormal modes of the massive Dirac field in d-dimensional Tangherlini spacetime
We consider quasinormal modes of the massive Dirac field in the background of a Schwarzschild- Tangherlini black hole. Different dimensions of the spacetime are considered, from d = 4 to d = 9. The quasinormal modes are calculated using two independent methods: WKB and continued fraction. We obtain the spectrum of quas...
1709.07864v3
2017-09-20
Non-Adiabatic Vibrational Damping of Molecular Adsorbates: Insights into Electronic Friction and the Role of Electronic Coherence
We present a perturbation approach rooted in time-dependent density-functional theory to calculate electron hole (eh)-pair excitation spectra during the non-adiabatic vibrational damping of adsorbates on metal surfaces. Our analysis for the benchmark systems CO on Cu(100) and Pt(111) elucidates the surprisingly strong ...
1709.08003v1
2017-09-28
Phenomenological model for predicting stationary and non-stationary spectra of wave turbulence in vibrating plates
A phenomenological model describing the time-frequency dependence of the power spectrum of thin plates vibrating in a wave turbulence regime, is introduced. The model equation contains as basic solutions the Rayleigh-Jeans equipartition of energy, as well as the Kolmogorov-Zakharov spectrum of wave turbulence. In the W...
1709.09884v1