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Related papers: Understanding the Magnetic Polarizability Tensor

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Realistic applications in metal detection involve multiple inhomogeneous conducting permeable objects and the aim of this paper is to characterise such objects by polarizability tensors. We show that, for the eddy current model, the leading…

Analysis of PDEs · Mathematics 2018-09-25 P. D. Ledger , W. R. B. Lionheart , A. A. S. Amad

The characterisation of small low conducting inclusions in an otherwise uniform background from low-frequency electrical field measurements has important applications in medical imaging using electrical impedance tomography as well as in…

Numerical Analysis · Mathematics 2022-06-24 A. A. S. Amad , P. D. Ledger , T. Betcke , D. Praetorius

We present a new complete asymptotic expansion for the low frequency time-harmonic magnetic field perturbation caused by the presence of a conducting (permeable) object as its size tends to zero for the eddy current regime of Maxwell's…

Analysis of PDEs · Mathematics 2018-05-23 P. D. Ledger , W. R. B. Lionheart

The measurement of time-harmonic perturbed field data, at a range of frequencies, is beneficial for practical metal detection where the goal is to locate and identify hidden targets. In particular, these benefits are realised when frequency…

Analysis of PDEs · Mathematics 2020-01-08 P. D. Ledger , W. R. B. Lionheart

We extend a microscopic theory of polarization and magnetization to include the spin degree of freedom of the electrons, introducing a general spin orbit coupling and Zeeman interaction term in the Hamiltonian. At finite frequencies and…

Mesoscale and Nanoscale Physics · Physics 2023-07-11 Alistair H. Duff , J. E. Sipe

Our interest lies in the identification of hidden conducting permeable objects from measurements of the perturbed magnetic field in metal detection taken over range of low frequencies. The magnetic polarizability tensor (MPT) provides a…

Numerical Analysis · Mathematics 2020-01-22 B. A. Wilson , P. D. Ledger

Purpose: Magnetic polarizability tensors (MPTs) provide an economical characterisation of conducting magnetic metallic objects and their spectral signature can aid in the solution of metal detection inverse problems, such as scrap metal…

Numerical Analysis · Mathematics 2024-05-01 James Elgy , Paul D. Ledger

(Electric) polarization tensors describe part of the leading order term of asymptotic voltage perturbations caused by low volume fraction inhomogeneities of the electrical properties of a medium. They depend on the geometry of the support…

Analysis of PDEs · Mathematics 2015-09-25 Roland Griesmaier , Martin Hanke

Current mathematical models for identifying highly conducting buried objects in metal detection assume that the soil is non-conducting and has the same permeability as free space. However, although the electrical conductivity of soil is…

Analysis of PDEs · Mathematics 2025-07-08 P. D. Ledger , W. R. B. Lionheart

The theory of electromagnetic in nature new component of electrical current is suggested. In classical physics approximations for the cases of the free electron plasmas in semi-conductive media, the atom or molecular electrons of liquids…

General Physics · Physics 2009-08-12 P. M. Mednis

We propose a mechanism for the recently reported destabilization by an in-plane magnetic field of the conducting phase of low density electrons in 2D. We apply our self-consistent approach based on the memory function formalism to the fully…

Strongly Correlated Electrons · Physics 2007-05-23 J. S. Thakur , D. Neilson

Mueller matrix polarimetry constitutes a nondestructive powerful tool for the analysis of material samples that is used today in an enormous variety of applications. Depolarizing samples exhibit, in general, a complicated physical behavior…

Optics · Physics 2020-01-08 Ignacio San José , José J. Gil

The inductive response of an object to an oscillating magnetic field reveals information about its electrical conductivity and magnetic permeability. Here we introduce a technique that uses measurements of the angular, frequency and spatial…

Applied Physics · Physics 2021-11-24 R. Gartman , W. Chalupczak

The orbital motion of electrons in a three-dimensional solid can generate a pseudoscalar magnetoelectric coupling $\theta$, a fact we derive for the single-particle case using a recent theory of polarization in weakly inhomogeneous…

Mesoscale and Nanoscale Physics · Physics 2009-12-16 Andrew M. Essin , Joel E. Moore , David Vanderbilt

We discuss the magnetization $M_m$ in the $m$-th column of the zig-zag layered 2D Ising model on a half-plane using Kadanoff-Ceva fermions and orthogonal polynomials techniques. Our main result gives an explicit representation of $M_m$ via…

Mathematical Physics · Physics 2022-12-27 Dmitry Chelkak , Clément Hongler , Rémy Mahfouf

A full-wave numerical scheme of polarisability tensors evaluation is presented. The method accepts highly conducting bodies of arbitrary shape and explicitly accounts for the radiation as well as ohmic losses. The method is verified on…

Computational Physics · Physics 2017-12-07 L. Jelinek , O. Kratky , M. Capek

We study two-dimensional interacting electrons in a weak perpendicular magnetic field with the filling factor $\nu \gg 1$ and in the presence of a quenched disorder. As it is known, the unidirectional charge density wave state can exist…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 I. S. Burmistrov

Magnetism - the spontaneous alignment of atomic moments in a material - is driven by quantum-mechanical `exchange' interactions which operate over atomic distances as a result of the fundamental symmetry of electrons. Currently, one of the…

An expression for the electrical conductivity at the core of a magnetar is derived using Boltzmann kinetic equation with the relaxation time approximation. The rates for the relevant scattering processes, e.g., electron-electron and…

For the coherently driven \Lambda-type three-level systems the general ready-to-calculate expression for the susceptibility tensor at the frequency of the weak probe field is obtained for the arbitrary polarization of the strong coupling…

Optics · Physics 2014-10-14 V. A. Reshetov , I. V. Meleshko
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