The Experts below are selected from a list of 4983 Experts worldwide ranked by ideXlab platform
P C W Holdsworth - One of the best experts on this subject based on the ideXlab platform.
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Signature of magnetic monopole and Dirac string dynamics in spin ice
Nature Physics, 2009Co-Authors: L. D.c. Jaubert, P C W HoldsworthAbstract:Magnetic monopoles have eluded experimental detection since their prediction nearly a century ago by Dirac. Recently it has been shown that classical analogues of these enigmatic particles occur as excitations out of the topological ground state of a model magnetic system, dipolar spin ice. These quasi-particle excitations do not require a modification of Maxwell's equations, but they do interact via Coulombs Law and are of magnetic origin. In this paper we present an experimentally measurable signature of monopole dynamics and show that magnetic relaxation measurements in the spin ice material $Dy_{2}Ti_{2}O_{7}$ can be interpreted entirely in terms of the diffusive motion of monopoles in the grand canonical ensemble, constrained by a network of "Dirac strings" filling the quasi-particle vacuum. In a magnetic field the topology of the network prevents charge flow in the steady state, but there is a monopole density gradient near the surface of an open system.
L. D.c. Jaubert - One of the best experts on this subject based on the ideXlab platform.
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Signature of magnetic monopole and Dirac string dynamics in spin ice
Nature Physics, 2009Co-Authors: L. D.c. Jaubert, P C W HoldsworthAbstract:Magnetic monopoles have eluded experimental detection since their prediction nearly a century ago by Dirac. Recently it has been shown that classical analogues of these enigmatic particles occur as excitations out of the topological ground state of a model magnetic system, dipolar spin ice. These quasi-particle excitations do not require a modification of Maxwell's equations, but they do interact via Coulombs Law and are of magnetic origin. In this paper we present an experimentally measurable signature of monopole dynamics and show that magnetic relaxation measurements in the spin ice material $Dy_{2}Ti_{2}O_{7}$ can be interpreted entirely in terms of the diffusive motion of monopoles in the grand canonical ensemble, constrained by a network of "Dirac strings" filling the quasi-particle vacuum. In a magnetic field the topology of the network prevents charge flow in the steady state, but there is a monopole density gradient near the surface of an open system.
Jerome Weiss - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of an assembly of rigid ice floes
Journal of Geophysical Research. Oceans, 2015Co-Authors: Matthias Rabatel, Stéphane Labbé, Jerome WeissAbstract:In this paper, we present a model describing the dynamics of a population of ice floes with arbitrary shapes and sizes, which are exposed to atmospheric and oceanic skin drag. The granular model presented is based on simplified momentum equations for ice floe motion between collisions and on the resolution of linear complementarity problems to deal with ice floe collisions. Between collisions, the motion of an individual ice floe satisfies the linear and angular momentum conservation equations, with classical formula applied to account for atmospheric and oceanic skin drag. To deal with collisions, before they lead to interpenetration, we included a linear complementarity problem based on the Signorini condition and Coulombs Law. The nature of the contact is described through a constant coefficient of friction μ, as well as a coefficient of restitution urn:x-wiley:21699275:media:jgrc21339:jgrc21339-math-0001 describing the loss of kinetic energy during the collision. In the present version of our model, this coefficient is fixed. The model was validated using data obtained from the motion of interacting artificial wood floes in a test basin. The results of simulations comprising few hundreds of ice floes of various shapes and sizes, exposed to different forcing scenarios, and under different configurations, are also discussed. They show that the progressive clustering of ice floes as the result of kinetic energy dissipation during collisions is well captured, and suggest a collisional regimes of floe dispersion at small scales, different from a large‐scale regime essentially driven by wind forcing.
Matthias Rabatel - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of an assembly of rigid ice floes
Journal of Geophysical Research. Oceans, 2015Co-Authors: Matthias Rabatel, Stéphane Labbé, Jerome WeissAbstract:In this paper, we present a model describing the dynamics of a population of ice floes with arbitrary shapes and sizes, which are exposed to atmospheric and oceanic skin drag. The granular model presented is based on simplified momentum equations for ice floe motion between collisions and on the resolution of linear complementarity problems to deal with ice floe collisions. Between collisions, the motion of an individual ice floe satisfies the linear and angular momentum conservation equations, with classical formula applied to account for atmospheric and oceanic skin drag. To deal with collisions, before they lead to interpenetration, we included a linear complementarity problem based on the Signorini condition and Coulombs Law. The nature of the contact is described through a constant coefficient of friction μ, as well as a coefficient of restitution urn:x-wiley:21699275:media:jgrc21339:jgrc21339-math-0001 describing the loss of kinetic energy during the collision. In the present version of our model, this coefficient is fixed. The model was validated using data obtained from the motion of interacting artificial wood floes in a test basin. The results of simulations comprising few hundreds of ice floes of various shapes and sizes, exposed to different forcing scenarios, and under different configurations, are also discussed. They show that the progressive clustering of ice floes as the result of kinetic energy dissipation during collisions is well captured, and suggest a collisional regimes of floe dispersion at small scales, different from a large‐scale regime essentially driven by wind forcing.
John Laurence Haller - One of the best experts on this subject based on the ideXlab platform.
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A Stocastic Explination of Newton’s Law and Coulombs’ Law
Global Journal of Science Frontier Research, 2014Co-Authors: John Laurence HallerAbstract:Assuming that a particle follows the discrete Bernoulli process with a step size proportional to one over twice its mass and that the vacuum is made up of particles with the reduced Planck mass, one can derive both Newton’s Law of Gravitation and Coulomb’s Law of Electric Force using slightly different parameters of the process. Twoclasses of experiments, which could affirm the hypothesis,would indicate a preferred reference frame.
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a stocastic explination of newton s Law and Coulombs Law
Global Journal of Science Frontier Research, 2014Co-Authors: John Laurence HallerAbstract:Assuming that a particle follows the discrete Bernoulli process with a step size proportional to one over twice its mass and that the vacuum is made up of particles with the reduced Planck mass, one can derive both Newton’s Law of Gravitation and Coulomb’s Law of Electric Force using slightly different parameters of the process. Twoclasses of experiments, which could affirm the hypothesis,would indicate a preferred reference frame.
