publicationDate
stringlengths
1
2.79k
title
stringlengths
1
36.5k
abstract
stringlengths
1
37.3k
id
stringlengths
9
47
2016-06-21
A stochastic model of supercoiling-dependent transcription
We propose a stochastic model for gene transcription coupled to DNA supercoiling, where we incorporate the experimental observation that polymerases create supercoiling as they unwind the DNA helix, and that these enzymes bind more favourably to regions where the genome is unwound. Within this model, we show that when ...
1606.06555v3
2016-06-22
Induced magnetization and power loss for a periodically driven system of ferromagnetic nanoparticles with randomly oriented easy axes
We study the effect of an elliptically polarized magnetic field on a system of non-interacting, single-domain ferromagnetic nanoparticles characterized by a uniform distribution of easy axis directions. Our main goal is to determine the average magnetization of this system and the power loss in it. In order to calculat...
1606.07131v1
2016-07-20
Performance of Topological Insulator Interconnects
The poor performance of copper interconnects at the nanometer scale calls for new material solutions for continued scaling of integrated circuits. We propose the use of three dimensional time-reversal-invariant topological insulators (TIs), which host backscattering-protected surface states, for this purpose. Using sem...
1607.06131v2
2016-07-21
Rate-distance tradeoff for codes above graph capacity
The capacity of a graph is defined as the rate of exponential growth of independent sets in the strong powers of the graph. In the strong power an edge connects two sequences if at each position their letters are equal or adjacent. We consider a variation of the problem where edges in the power graphs are removed betwe...
1607.06384v1
2016-07-25
A geometric approach to optimal nonequilibrium control: Minimizing dissipation in nanomagnetic spin systems
Optimal control of nanomagnets has become an urgent problem for the field of spintronics as technological tools approach thermodynamically determined limits of efficiency. In complex, fluctuating systems, like nanomagnetic bits, finding optimal protocols is challenging, requiring detailed information about the dynamica...
1607.07425v1
2016-08-02
Affordable echelle spectroscopy of the eccentric HAT-P-2, WASP-14 and XO-3 planetary systems with a sub-meter-class telescope
A new off-shelf low-cost echelle spectrograph was installed recently on the 0.6m telescope at the Star\'a Lesn\'a Observatory (Slovakia). In this paper we describe in details the radial velocity (RV) analysis of the first three transiting planetary systems, HAT-P-2, WASP-14 and XO-3, observed with this instrument. Furt...
1608.00745v1
2016-08-06
High current, high efficiency graded band gap perovskite solar cells
Organic-inorganic halide perovskite materials have emerged as attractive alternatives to conventional solar cell building blocks. Their high light absorption coefficients and long diffusion lengths suggest high power conversion efficiencies (PCE),1-5 and indeed perovskite-based single band gap and tandem solar cell des...
1608.02150v1
2016-08-09
Existence of weak solutions to an evolutionary model for magnetoelasticity
We prove existence of weak solutions to an evolutionary model derived for magnetoelastic materials. The model is phrased in Eulerian coordinates and consists in particular of (i) a Navier-Stokes equation that involves magnetic and elastic terms in the stress tensor obtained by a variational approach, of (ii) a regulari...
1608.02992v1
2016-08-16
Magnetic Yoking and Tunable Interactions in FePt-Based Hard/Soft Bilayers
Assessing and controlling magnetic interactions in magnetic nanostructures are critical to nanomagnetic and spintronic explorations, such as magnetic recording media, permanent magnets, magnetic memory and logic devices, etc. Here we demonstrate an extremely sensitive magnetic yoking effect and tunable interactions in ...
1608.04630v1
2016-08-17
Current-induced instability of domain walls in cylindrical nanowires
We study the current-driven domain wall (DW) motion in cylindrical nanowires using micromagnetic simulations by implementing the Landau-Lifshitz-Gilbert equation with nonlocal spin-transfer torque in a finite difference micromagnetic package. We find that in the presence of DW Gaussian wave packets (spin waves) will be...
1608.04876v2
2016-08-22
Disorder Induced Phase Transitions of Type-II Weyl Semimetal
Weyl semimetals are a newly discovered class of materials that host relativistic massless Weyl fermions as their low-energy bulk excitations. Among this new class of materials, there exist two general types of semimetals that are of particular interest: type-I Weyl semimetals, that have broken inversion or time-reversa...
1608.06311v1
2016-08-25
Convergence of a mass-lumped finite element method for the Landau-Lifshitz equation
The dynamics of the magnetic distribution in a ferromagnetic material is governed by the Landau-Lifshitz equation, which is a nonlinear geometric dispersive equation with a nonconvex constraint that requires the magnetization to remain of unit length throughout the domain. In this article, we present a mass-lumped fini...
1608.07312v3
2016-08-30
LiRa: A New Likelihood-Based Similarity Score for Collaborative Filtering
Recommender system data presents unique challenges to the data mining, machine learning, and algorithms communities. The high missing data rate, in combination with the large scale and high dimensionality that is typical of recommender systems data, requires new tools and methods for efficient data analysis. Here, we a...
1608.08646v2
2016-09-09
An Empirical Study of Cycle Toggling Based Laplacian Solvers
We study the performance of linear solvers for graph Laplacians based on the combinatorial cycle adjustment methodology proposed by [Kelner-Orecchia-Sidford-Zhu STOC-13]. The approach finds a dual flow solution to this linear system through a sequence of flow adjustments along cycles. We study both data structure orien...
1609.02957v1
2016-09-21
Harmonic space analysis of pulsar timing array redshift maps
In this paper, we propose a new framework for treating the angular information in the pulsar timing array response to a gravitational wave background based on standard cosmic microwave background techniques. We calculate the angular power spectrum of the all-sky gravitational redshift pattern induced at the earth for b...
1609.06758v2
2016-09-22
Ultrafast generation of skyrmionic defects with vortex beams: printing laser profiles on magnets
Controlling electric and magnetic properties of matter by laser beams is actively explored in the broad region of condensed matter physics, including spintronics and magneto-optics. Here we theoretically propose an application of optical and electron vortex beams carrying intrinsic orbital angular momentum to chiral fe...
1609.06816v3
2016-10-02
Syntactic Structures and Code Parameters
We assign binary and ternary error-correcting codes to the data of syntactic structures of world languages and we study the distribution of code points in the space of code parameters. We show that, while most codes populate the lower region approximating a superposition of Thomae functions, there is a substantial pres...
1610.00311v1
2016-10-03
Linear dynamics of classical spin as Möbius transformation
Although the overwhelming majority of natural processes occurs far from the equilibrium, general theoretical approaches to non-equilibrium phase transitions remain scarce. Recent breakthroughs introducing description of open dissipative systems in terms of non-Hermitian quantum mechanics allowed to identify a class of ...
1610.00762v1
2016-10-11
Self-Consistent Field Theory studies of the thermodynamics and quantum spin dynamics of magnetic Skyrmions
A self-consistent field theory is introduced and used to investigate the thermodynamics and spin dynamics of an $S = 1$ quantum spin system with a magnetic Skyrmion. The temperature dependence of the Skyrmion profile as well as the phase diagram are calculated. It is shown that the Skyrmion carries a phase transition t...
1610.03191v2
2016-10-12
Variational approximation of functionals defined on 1-dimensional connected sets: the planar case
In this paper we consider variational problems involving 1-dimensional connected sets in the Euclidean plane, such as the classical Steiner tree problem and the irrigation (Gilbert-Steiner) problem. We relate them to optimal partition problems and provide a variational approximation through Modica-Mortola type energies...
1610.03839v5
2016-10-24
Field-free, spin-current control of magnetization in non-collinear chiral antiferromagnets
Non-collinear chiral antiferromagnets like Mn3Sn and Mn3Ge are known to show gigantic anomalous Hall response depending on the orientation of their inverse chiral magnetic order of Mn atoms in Kagome layers. Here we study the stability of such magnetic order in the absence of external magnetic fields on the basis of st...
1610.07615v2
2016-11-04
Struwe-like solutions for the Stochastic Harmonic Map Flow
We give a new result on the well-posedness of the two-dimensional Stochastic Harmonic Map flow, whose study is motivated by the Landau-Lifshitz-Gilbert model for thermal fluctuations in micromagnetics. We construct strong solutions that belong locally to the spaces $C([s,t);H^1)\cap L^2([s,t);H^2)$, $0\leq s<t\leq T$. ...
1611.01565v2
2016-11-07
Compactness results for static and dynamic chiral skyrmions near the conformal limit
We examine lower order perturbations of the harmonic map prob- lem from $\mathbb{R}^2$ to $\mathbb{S}^2$ including chiral interaction in form of a helicity term that prefers modulation, and a potential term that enables decay to a uniform background state. Energy functionals of this type arise in the context of magneti...
1611.01984v1
2016-11-08
A variational method for spectral functions
The Generalized Eigenvalue Problem (GEVP) has been used extensively in the past in order to reliably extract energy levels from time-dependent Euclidean correlators calculated in Lattice QCD. We propose a formulation of the GEVP in frequency space. Our approach consists of applying the model-independent Backus-Gilbert ...
1611.02499v1
2016-11-14
Hidden fluctuations close to a quantum bicritical point
In this paper we describe physical properties arising in the vicinity of two coupled quantum phase transitions. We consider a phenomenological model based on two scalar order parameter fields locally coupled biquadratically and having a common quantum critical point as a function of a quantum tuning parameter such as p...
1611.04621v2
2016-11-22
New bounds of permutation codes under Hamming metric and Kendall's $τ$-metric
Permutation codes are widely studied objects due to their numerous applications in various areas, such as power line communications, block ciphers, and the rank modulation scheme for flash memories. Several kinds of metrics are considered for permutation codes according to their specific applications. This paper concer...
1611.07188v1
2016-12-01
Encoding orbital angular momentum of light in magnets
Breaking the diffraction limit and focusing laser beams to subwavelength scale are becoming possible with the help of recent developments in plasmonics. Such subwavelength focusing bridges different length scales of laser beams and matter. Here we consider optical vortex, or laser beam carrying orbital angular momentum...
1612.00176v2
2016-12-26
Credibility and Dynamics of Collective Attention
Today, social media provide the means by which billions of people experience news and events happening around the world. However, the absence of traditional journalistic gatekeeping allows information to flow unencumbered through these platforms, often raising questions of veracity and credibility of the reported infor...
1612.08440v1
2017-01-07
Modulation calorimetry in diamond anvil cells I: heat flow models
Numerical simulations of heat transport in diamond anvil cells reveal a possibility for absolute measurements of specific heat via high-frequency modulation calorimetry. Such experiments could reveal and help characterize temperature-driven phase transitions at high-pressure, such as melting, the glass transition, magn...
1701.01872v1
2017-01-08
Topological crystalline superconductors with linearly and projectively represented $C_{n}$ symmetry
We study superconductors with $n$-fold rotational invariance both in the presence and in the absence of spin-orbit interactions. More specifically, we classify the non-interacting Hamiltonians by defining a series of $Z$-numbers for the Bogoliubov-de Gennes (BdG) symmetry classes of the Altland-Zimbauer classification ...
1701.01944v1
2017-01-09
Temperature dependence of shear viscosity of $SU(3)$--gluodynamics within lattice simulation
In this paper we study the shear viscosity temperature dependence of $SU(3)$--gluodynamics within lattice simulation. To do so, we measure the correlation functions of energy-momentum tensor in the range of temperatures $T/T_c\in [0.9, 1.5]$. To extract the values of shear viscosity we used two approaches. The first on...
1701.02266v2
2017-01-25
Statistical Decoding
The security of code-based cryptography relies primarily on the hardness of generic decoding with linear codes. The best generic decoding algorithms are all improvements of an old algorithm due to Prange: they are known under the name of information set decoding techniques (ISD). A while ago a generic decoding algorith...
1701.07416v2
2017-02-03
Enhanced Spin Conductance of a Thin-Film Insulating Antiferromagnet
We investigate spin transport by thermally excited spin waves in an antiferromagnetic insulator. Starting from a stochastic Landau-Lifshitz-Gilbert phenomenology, we obtain the out-of-equilibrium spin-wave properties. In linear response to spin biasing and a temperature gradient, we compute the spin transport through a...
1702.00975v2
2017-02-07
Giant-spin nonlinear response theory of magnetic nanoparticle hyperthermia: a field dependence study
Understanding high-field amplitude electromagnetic heat loss phenomena is of great importance, in particular in the biomedical field, since the heat-delivery treatment plans might rely on analytical models that are only valid at low field amplitudes. Here, we develop a nonlinear response model valid for single- domain ...
1702.02022v1
2017-02-17
Spin-orbit torque in MgO/CoFeB/Ta/CoFeB/MgO symmetric structure with interlayer antiferromagnetic coupling
Spin current generated by spin Hall effect in the heavy metal would diffuse up and down to adjacent ferromagnetic layers and exert torque on their magnetization, called spin-orbit torque. Antiferromagnetically coupled trilayers, namely the so-called synthetic antiferromagnets (SAF), are usually employed to serve as the...
1702.05331v1
2017-02-19
Multiscale simulations of topological transformations in magnetic Skyrmions
Magnetic Skyrmions belong to the most interesting spin structures for the development of future information technology as they have been predicted to be topologically protected. To quantify their stability, we use an innovative multiscale approach to simulating spin dynamics based on the Landau-Lifshitz-Gilbert equatio...
1702.05767v1
2017-02-21
Spin texture motion in antiferromagnetic and ferromagnetic nanowires
We propose a Hamiltonian dynamics formalism for the current and magnetic field driven dynamics of ferromagnetic and antiferromagnetic domain walls in one dimensional systems. To demonstrate the power of this formalism, we derive Hamilton equations of motion via Poisson brackets based on the Landau-Lifshitz-Gilbert phen...
1702.06274v1
2017-02-23
Fulde-Ferrell States in Inverse Proximity Coupled Magnetically-Doped Topological Heterostructures
We study the superconducting properties of the thin film BCS superconductor proximity coupled to a magnetically doped topological insulator(TI). Using the mean field theory, we show that Fulde-Ferrell(FF) pairing can be induced in the conventional superconductor by having inverse proximity effect(IPE). This occurs when...
1702.07383v1
2017-02-27
Quantum critical scaling and fluctuations in Kondo lattice materials
We propose a new phenomenological framework for three classes of Kondo lattice materials that incorporates the interplay between the fluctuations associated with the antiferromagnetic quantum critical point and those produced by the hybridization quantum critical point that marks the end of local moment behavior. We sh...
1702.08132v2
2017-03-09
On linear complementary-dual multinegacirculant codes
Linear codes with complementary-duals (LCD) are linear codes that intersect with their dual trivially. Multinegacirculant codes of index $2$ that are LCD are characterized algebraically and some good codes are found in this family. Exact enumeration is performed for indices 2 and 3, and for all indices $t$ for a specia...
1703.03115v1
2017-03-16
Electronic transport in a two-dimensional superlattice engineered via self-assembled nanostructures
Nanoscience offers a unique opportunity to design modern materials from the bottom up, via low-cost, solution processed assembly of nanoscale building blocks. These systems promise electronic band structure engineering using not only the nanoscale structural modulation, but also the mesoscale spatial patterning, althou...
1703.05689v3
2017-03-27
Dipolar ferromagnetism in three-dimensional superlattices of nanoparticles
A series of atomistic finite temperature simulations on a model of an FCC lattice of maghemite nanoparticles using the stochastic Landau-Lifshitz-Gilbert (sLLG) equation are presented. The model exhibits a ferromagnetic transition that is in good agreement with theoretical expectations. The simulations also reveal an o...
1703.09290v1
2017-03-06
Ultralow Energy Analog Straintronics Using Multiferroic Composites
Electric field-induced magnetization switching in multiferroics holds profound promise for ultra-low-energy computing in beyond Moore's law era. Bistable nanomagnets in the multiferroics are usually deemed to be suitable for storing a binary bit of information and switching between the two stable states allows us to pr...
1704.02337v1
2017-04-12
The gradient condition and the contribution of the dynamical part of Green-Kubo formula to the diffusion coefficient
In the diffusive hydrodynamic limit for a symmetric interacting particle system (such as the exclusion process, the zero range process, the stochastic Ginzburg-Landau model, the energy exchange model), a possibly non-linear diffusion equation is derived as the hydrodynamic equation. The bulk diffusion coefficient of th...
1704.03745v2
2017-04-12
The Origin of Sequential Chromospheric Brightenings
Sequential chromospheric brightenings (SCBs) are often observed in the immediate vicinity of erupting flares and are associated with coronal mass ejections. Since their initial discovery in 2005, there have been several subsequent investigations of SCBs. These studies have used differing detection and analysis techniqu...
1704.03828v1
2017-04-12
Relationships Between Sequential Chromospheric Brightening and the Corona
The chromosphere is a complex region that acts as an intermediary between the magnetic flux emergence in the photosphere and the magnetic features seen in the corona. Large eruptions in the chromosphere of flares and filaments are often accompanied by ejections of coronal mass off the sun. Several studies have observed...
1704.03835v1
2017-05-16
Constructive mathematics
This text is reproduced with the kind permission of Fran\c{c}ois Ap\'ery. It was originally edited by Fran\c{c}ois Gu\'enard and Gilbert Leli\`evre for the book "Penser les math\'ematiques". It is the modified and abridged version of a text that appeared previously as S\'eminaire de philosophie et math\'ematiques d...
1705.05581v2
2017-05-17
Magnetic-Visual Sensor Fusion based Medical SLAM for Endoscopic Capsule Robot
A reliable, real-time simultaneous localization and mapping (SLAM) method is crucial for the navigation of actively controlled capsule endoscopy robots. These robots are an emerging, minimally invasive diagnostic and therapeutic technology for use in the gastrointestinal (GI) tract. In this study, we propose a dense, n...
1705.06196v2
2017-05-21
First-Order Reversal Curves of the Magnetostructural Phase Transition in FeTe
We apply the first-order reversal curve (FORC) method, borrowed from studies of ferromagnetic materials, to the magneto-structural phase transition of FeTe. FORC measurements reveal two features in the hysteretic phase transition, even in samples where traditional temperature measurements display only a single transiti...
1705.07380v1
2017-05-24
Towards Understanding the Invertibility of Convolutional Neural Networks
Several recent works have empirically observed that Convolutional Neural Nets (CNNs) are (approximately) invertible. To understand this approximate invertibility phenomenon and how to leverage it more effectively, we focus on a theoretical explanation and develop a mathematical model of sparse signal recovery that is c...
1705.08664v1
2017-03-06
Ultra-low-energy Electric field-induced Magnetization Switching in Multiferroic Heterostructures
Electric field-induced magnetization switching in multiferroics is intriguing for both fundamental studies and potential technological applications. Here, we review the recent developments on electric field-induced magnetization switching in multiferroic heterostructures. Particularly, we study the dynamics of magnetiz...
1706.03039v1
2017-06-11
Local List Recovery of High-rate Tensor Codes and Applications
In this work, we give the first construction of high-rate locally list-recoverable codes. List-recovery has been an extremely useful building block in coding theory, and our motivation is to use these codes as such a building block. In particular, our construction gives the first capacity-achieving locally list-decodab...
1706.03383v1
2017-05-31
Local Differential Privacy for Physical Sensor Data and Sparse Recovery
In this work we explore the utility of locally differentially private thermal sensor data. We design a locally differentially private recovery algorithm for the 1-dimensional, discrete heat source location problem and analyse its performance in terms of the Earth Mover Distance error. Our work indicates that it is poss...
1706.05916v4
2017-06-22
High-performance nanoscale topological energy transduction
The realization of high-performance, small-footprint, on-chip inductors remains a challenge in radio-frequency and power microelectronics, where they perform vital energy transduction in filters and power converters. Modern planar inductors consist of metallic spirals that consume significant chip area, resulting in lo...
1706.07381v1
2017-06-28
Extension and Applications of a Variational Approach with Deformed Derivatives
We have recently presented an extension of the standard variational calculus to include the presence of deformed derivatives in the Lagrangian of a system of particles and in the Lagrangian density of field-theoretic models. Classical Euler-Lagrange equations and the Hamiltonian formalism have been re-assessed in this ...
1706.09504v1
2017-07-06
Relaxation time and critical slowing down of a spin-torque oscillator
The relaxation phenomena of spin-torque oscillators consisting of nanostructured ferromagnets are interesting research targets in magnetism. A theoretical study on the relaxation time of a spin-torque oscillator from one self-oscillation state to another is investigated. By solving the Landau-Lifshitz-Gilbert equation ...
1707.01960v1
2017-07-07
Pandeia: A Multi-mission Exposure Time Calculator for JWST and WFIRST
Pandeia is the exposure time calculator (ETC) system developed for the James Webb Space Telescope (JWST) that will be used for creating JWST proposals. It includes a simulation-hybrid Python engine that calculates the two-dimensional pixel-by-pixel signal and noise properties of the JWST instruments. This allows for ap...
1707.02202v2
2017-07-10
Convex optimization over classes of multiparticle entanglement
A well-known strategy to characterize multiparticle entanglement utilizes the notion of stochastic local operations and classical communication (SLOCC), but characterizing the resulting entanglement classes is difficult. Given a multiparticle quantum state, we first show that Gilbert's algorithm can be adapted to prove...
1707.02958v3
2017-07-13
Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model
In this article, we discuss the non-trivial collective charge excitations (plasmons) of the extended square-lattice Hubbard model. Using a fully non-perturbative approach, we employ the hybrid Monte Carlo algorithm to simulate the system at half-filling. A modified Backus-Gilbert method is introduced to obtain the spec...
1707.04212v2
2017-07-25
Partially Ionized Plasmas in Astrophysics
Partially ionized plasmas are found across the Universe in many different astrophysical environments. They constitute an essential ingredient of the solar atmosphere, molecular clouds, planetary ionospheres and protoplanetary disks, among other environments, and display a richness of physical effects which are not pres...
1707.07975v2
2017-07-14
Spatially variant PSF modeling in confocal macroscopy
Point spread function (PSF) plays an essential role in image reconstruction. In the context of confocal microscopy, optical performance degrades towards the edge of the field of view as astigmatism, coma and vignetting. Thus, one should expect the related artifacts to be even stronger in macroscopy, where the field of ...
1707.09858v1
2017-08-09
Bubble Magnetometry of Nanoparticle Heterogeneity and Interaction
Bubbles have a rich history as transducers in particle-physics experiments. In a solid-state analogue, we use bubble domains in nanomagnetic films to measure magnetic nanoparticles. This technique can determine the magnetic orientation of a single nanoparticle in a fraction of a second, and generate a full hysteresis l...
1708.02706v2
2017-08-18
Antiferromagnetic nano-oscillator in external magnetic fields
We describe the dynamics of an antiferromagnetic nano-oscillator in an external magnetic field of any given time distribution. The oscillator is powered by a spin current originating from spin-orbit effects in a neighboring heavy metal layer, and is capable of emitting a THz signal in the presence of an additional easy...
1708.05590v2
2017-09-07
A sharp bound for winning within a proportion of the maximum of a sequence
This note considers a variation of the full-information secretary problem where the random variables to be observed are independent and identically distributed. Consider $X_1,\dots,X_n$ to be an independent sequence of random variables, let $M_n:=\max\{X_1,\dots,X_n\}$, and the objective is to select the maximum of the...
1709.02416v1
2017-09-18
Endo-VMFuseNet: Deep Visual-Magnetic Sensor Fusion Approach for Uncalibrated, Unsynchronized and Asymmetric Endoscopic Capsule Robot Localization Data
In the last decade, researchers and medical device companies have made major advances towards transforming passive capsule endoscopes into active medical robots. One of the major challenges is to endow capsule robots with accurate perception of the environment inside the human body, which will provide necessary informa...
1709.06041v2
2017-09-22
On self-dual negacirculant codes of index two and four
In this paper, we study a special kind of factorization of $x^n+1$ over $\mathbb{F}_q, $ with $q$ a prime power $\equiv 3~({\rm mod}~4)$ when $n=2p,$ with $p\equiv 3~({\rm mod}~4)$ and $p$ is a prime. Given such a $q$ infinitely many such $p$'s exist that admit $q$ as a primitive root by the Artin conjecture in arithme...
1709.07546v2
2017-03-06
Ultra-Low-Energy Straintronics Using Multiferroic Composites
The primary impediment to continued improvement of charge-based electronics is the excessive energy dissipation incurred in switching a bit of information. With suitable choice of materials, devices made of multiferroic composites, i.e., strain-coupled piezoelectric-magnetostrictive heterostructures, dissipate miniscul...
1710.00612v1
2017-10-12
Modeling the aging kinetics of zirconia ceramics
Yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) with different microstructures were elaborated. The isothermal tetragonal to monoclinic transformation was investigated at 134 {\deg}C in steam by X-ray diffraction, Atomic Force Microscopy (AFM) and optical interferometry. The aging kinetics were analyzed in ...
1710.04454v1
2017-10-13
Microstructural investigation of the aging behavior of $(3Y-TZP)-Al_2O_3$ composites
The low temperature autoclave aging behavior of zirconia toughened alumina composites processed by a classical powder mixing processing route was analyzed using atomic force microscopy (AFM), scanning electron microscopy and X-Ray diffraction. The transformation was evaluated in terms of nucleation and growth, assessed...
1710.04923v1
2017-10-16
Tunable Low Density Palladium Nanowire Foams
Nanostructured palladium foams offer exciting potential for applications in diverse fields such as catalyst, fuel cell, and particularly hydrogen storage technologies. We have fabricated palladium nanowire foams using a cross-linking and freeze-drying technique. These foams have a tunable density down to 0.1% of the bu...
1710.05906v1
2017-10-19
An estimate for the thermal photon rate from lattice QCD
We estimate the production rate of photons by the quark-gluon plasma in lattice QCD. We propose a new correlation function which provides better control over the systematic uncertainty in estimating the photon production rate at photon momenta in the range {\pi}T/2 to 2{\pi}T. The relevant Euclidean vector current corr...
1710.07050v1
2017-10-26
Spin dynamics in MgO based magnetic tunnel junctions with dynamical exchange coupling
We study the spin dynamics in Fe|MgO|Fe tunnel junction with the dynamical exchange coupling by coupled Landau-Lifshitz-Gilbert equations. The effects of spin pumping on the spin dynamics are investigated in detail. It is observed that the spin pumping can stabilize a quasi-antiparallel state rather than a quasi-parall...
1710.09666v2
2017-10-27
Bulk and edge spin transport in topological magnon insulators
We investigate the spin transport properties of a topological magnon insulator, a magnetic insulator characterized by topologically nontrivial bulk magnon bands and protected magnon edge modes located in the bulk band gaps. Employing the Landau-Lifshitz-Gilbert phenomenology, we calculate the spin current driven throug...
1710.09998v2
2017-10-30
Spin-transfer Antiferromagnetic Resonance
Currents can induce spin excitations in antiferromagnets, even when they are insulating. We investigate how spin transfer can cause antiferromagnetic resonance in bilayers and trilayers that consist of one antiferromagnetic insulator and one or two metals. An ac voltage applied to the metal generates a spin Hall curren...
1710.10909v1
2017-10-31
Compact Multi-Class Boosted Trees
Gradient boosted decision trees are a popular machine learning technique, in part because of their ability to give good accuracy with small models. We describe two extensions to the standard tree boosting algorithm designed to increase this advantage. The first improvement extends the boosting formalism from scalar-val...
1710.11547v1
2017-11-14
Stationary Vacuum Black Holes in 5 Dimensions
We study the problem of asymptotically flat bi-axially symmetric stationary solutions of the vacuum Einstein equations in $5$-dimensional spacetime. In this setting, the cross section of any connected component of the event horizon is a prime $3$-manifold of positive Yamabe type, namely the $3$-sphere $S^3$, the ring $...
1711.05229v2
2017-11-27
Voltage induced switching of an antiferromagnetically ordered topological Dirac semimetal
An antiferromagnetic semimetal has been recently identified as a new member of topological semimetals that may host three-dimensional symmetry-protected Dirac fermions. A reorientation of the N\'{e}el vector may break the underlying symmetry and open a gap in the quasi-particle spectrum, inducing the (semi)metal-insula...
1711.09926v2
2017-12-11
Convergent tangent plane integrators for the simulation of chiral magnetic skyrmion dynamics
We consider the numerical approximation of the Landau-Lifshitz-Gilbert equation, which describes the dynamics of the magnetization in ferromagnetic materials. In addition to the classical micromagnetic contributions, the energy comprises the Dzyaloshinskii-Moriya interaction, which is the most important ingredient for ...
1712.03795v3
2017-12-31
Proper dissipative torques in antiferromagnetic dynamics
There is little doubt that the magnetization dynamics of ferromagnetic systems is governed by the Landau-Lifshitz-Gilbert equation or its generalization with various spin torques. In contrast, there are several sets of dynamic equations for two-sublattice antiferromagnets (AFMs) in literature that have different forms ...
1801.00217v1
2018-01-12
Optimal Streaming Codes for Channels with Burst and Arbitrary Erasures
This paper considers transmitting a sequence of messages (a streaming source) over a packet erasure channel. In each time slot, the source constructs a packet based on the current and the previous messages and transmits the packet, which may be erased when the packet travels from the source to the destination. Every so...
1801.04241v2
2018-01-16
Detecting Electron Density Fluctuations from Cosmic Microwave Background Polarization using a Bispectrum Approach
Recent progress in high sensitivity Cosmic Microwave Background (CMB) polarization experiments opens up a window on large scale structure (LSS), as CMB polarization fluctuations on small angular scales can arise from a combination of LSS and ionization fluctuations in the late universe. Gravitational lensing effects ca...
1801.05396v1
2018-01-18
Magpy: A C++ accelerated Python package for simulating magnetic nanoparticle stochastic dynamics
Magpy is a C++ accelerated Python package for modelling and simulating the magnetic dynamics of nano-sized particles. Nanoparticles are modelled as a system of three-dimensional macrospins and simulated with a set of coupled stochastic differential equations (the Landau-Lifshitz-Gilbert equation), which are solved nume...
1801.06073v2
2018-01-22
On the List Decodability of Self-orthogonal Rank Metric Codes
V. Guruswami and N. Resch prove that the list decodability of $\mathbb{F}_q$-linear rank metric codes is as good as that of random rank metric codes in~\cite{venkat2017}. Due to the potential applications of self-orthogonal rank metric codes, we focus on list decoding of them. In this paper, we prove that with high pro...
1801.07033v1
2018-01-25
Smoothing Algorithms for Computing the Projection onto a Minkowski Sum of Convex Sets
In this paper, the problem of computing the projection, and therefore the minimum distance, from a point onto a Minkowski sum of general convex sets is studied. Our approach is based on the minimum norm duality theorem originally stated by Nirenberg and the Nesterov smoothing techniques. It is shown that projection poi...
1801.08285v1
2018-01-25
Finite momentum Cooper pairing in 3D topological insulator Josephson junctions
Unconventional superconductivity arising from the interplay between strong spin-orbit coupling and magnetism is an intensive area of research. One form of unconventional superconductivity arises when Cooper pairs subjected to a magnetic exchange coupling acquire a finite momentum. Here, we report on a signature of fini...
1801.08504v1
2018-01-31
Numerical analytic continuation of Euclidean data
In this work we present a direct comparison of three different numerical analytic continuation methods: the Maximum Entropy Method, the Backus-Gilbert method and the Schlessinger point or Resonances Via Pad\'{e} method. First, we perform a benchmark test based on a model spectral function and study the regime of applic...
1801.10348v2
2018-02-03
Stochastic dynamics of planar magnetic moments in a three-dimensional environment
We study the stochastic dynamics of a two-dimensional magnetic moment embedded in a three-dimensional environment, described by means of the stochastic Landau-Lifshitz-Gilbert (sLLG) equation. We define a covariant generalization of this equation, valid in the "generalized Stratonovich discretization prescription". We ...
1802.01027v2
2018-02-07
Asymptotically Locally Euclidean/Kaluza-Klein Stationary Vacuum Black Holes in 5 Dimensions
We produce new examples, both explicit and analytical, of bi-axisymmetric stationary vacuum black holes in 5 dimensions. A novel feature of these solutions is that they are asymptotically locally Euclidean in which spatial cross-sections at infinity have lens space $L(p,q)$ topology, or asymptotically Kaluza-Klein so t...
1802.02457v2
2018-02-16
A Reallocation Algorithm for Online Split Packing of Circles
The Split Packing algorithm \cite{splitpacking_ws, splitpackingsoda, splitpacking} is an offline algorithm that packs a set of circles into triangles and squares up to critical density. In this paper, we develop an online alternative to Split Packing to handle an online sequence of insertions and deletions, where the a...
1802.05873v3
2018-02-22
Super-Resolution 1H Magnetic Resonance Spectroscopic Imaging utilizing Deep Learning
Magnetic resonance spectroscopic imaging (SI) is a unique imaging technique that provides biochemical information from in vivo tissues. The 1H spectra acquired from several spatial regions are quantified to yield metabolite concentrations reflective of tissue metabolism. However, since these metabolites are found in ti...
1802.07909v3
2018-02-26
Devil's Staircases in SFS Josephson Junctions
We study the effect of coupling between the superconducting current and magnetization in the superconductor/ferromagnet/superconductor Josephson junction under an applied circularly polarized magnetic field. Manifestation of ferromagnetic resonance in the frequency dependence of the amplitude of the magnetization and t...
1802.09212v2
2018-02-26
Controlled creation and stability of kπ-skyrmions on a discrete lattice
We determine sizes and activation energies of k{\pi}-skyrmions on a discrete lattice using the Landau- Lifshitz-Gilbert equation and the geodesic nudged elastic band method. The employed atomic material parameters are based on the skyrmionic material system Pd/Fe/Ir(111). We find that the critical magnetic fields for c...
1802.09257v1
2018-03-14
Subnanosecond magnetization reversal of magnetic nanoparticle driven by chirp microwave field pulse
We investigate the magnetization reversal of single-domain magnetic nanoparticle driven by linear down-chirp microwave magnetic field pulse. Numerical simulations based on the Landau-Lifshitz-Gilbert equation reveal that solely down-chirp pulse is capable of inducing subnanosecond magnetization reversal. With a certain...
1803.05261v1
2018-03-14
Dynamics of distorted skyrmions in strained chiral magnets
In this work, we study the microscopic dynamics of distorted skyrmions in strained chiral magnets [K. Shibata et al., Nat. Nanotech. 10, 589 (2015)] under gradient magnetic field or electric current by Landau-Lifshitz-Gilbert simulations of the anisotropic spin model. It is observed that the dynamical responses are als...
1803.05298v1
2018-03-19
Dynamics and Stability of Meshed Multiterminal HVDC Networks
This paper investigates the existence of an equilibrium point in multiterminal HVDC (MT-HVDC) grids, assesses its uniqueness and defines conditions to ensure its stability. An offshore MT-HVDC system including two wind farms is selected as application test case. At first, a generalized dynamic model of the network is p...
1803.06892v2
2018-03-16
Motion of vortices in ferromagnetic spin-1 BEC
The paper investigates dynamics of nonsingular vortices in a ferromagnetic spin-1 BEC, where spin and mass superfluidity coexist in the presence of uniaxial anisotropy (linear and quadratic Zeeman effect). The analysis is based on hydrodynamics following from the Gross-Pitaevskii theory. Cores of nonsingular vortices a...
1803.06939v1
2018-03-22
Mapping ideals of quantum group multipliers
We study the dual relationship between quantum group convolution maps $L^1(\mathbb{G})\rightarrow L^{\infty}(\mathbb{G})$ and completely bounded multipliers of $\widehat{\mathbb{G}}$. For a large class of locally compact quantum groups $\mathbb{G}$ we completely isomorphically identify the mapping ideal of row Hilbert ...
1803.08342v2
2018-03-28
Low-temperature ageing of zirconia-toughened alumina ceramics and its implication in biomedical implants
Changes in crystalline phases resulting from low-temperature ageing of different yttria doped and non-doped zirconia-toughened alumina composites and nanocomposites were investigated under controlled humidity and temperature conditions in autoclave. A classical powder mixing processing route and a new modified colloida...
1803.10465v1
2018-03-28
Accelerated Aging in 3 mol%-Yttria-Stabilized Tetragonal Zirconia Ceramics Sintered in Reducing Conditions
The aging behavior of 3-mol%-yttria-stabilized tetragonal zirconia (3Y-TZP) ceramics sintered in air and in reducing conditions was investigated at 140{\deg}C in water vapor. It was observed by X-ray diffraction (XRD) that 3Y-TZP samples sintered in reducing conditions exhibited significantly higher tetragonal-to-monoc...
1803.10580v1
2018-03-30
Atomic force microscopy study of the surface degradation mechanisms of zirconia based ceramics
Atomic force microscopy (AFM) can be used to characterise several aspects of the surface degradation and reinforcement mechanisms of zirconia based ceramics, such as crack propagation, martensitic relief formation, grains pull-out and transformation toughening. AFM can also be used to quantify precisely the transformat...
1804.00002v1