The Experts below are selected from a list of 165684 Experts worldwide ranked by ideXlab platform
Masaki Oshikawa - One of the best experts on this subject based on the ideXlab platform.
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Field induced gap in cu benzoate and other s 1 2 antiferromagnetic chains
Physical Review B, 1999Co-Authors: Ian Affleck, Masaki OshikawaAbstract:Recent experiments on the $S=\frac{1}{2}$ antiferromagnetic chain compound, Cu benzoate, discovered an unexpected gap scaling as approximately the $\frac{2}{3}$ power of an applied magnetic Field. A theory of this gap, based on an effective staggered Field, orthogonal to the applied Uniform Field, resulting from a staggered gyromagnetic tensor and a Dzyaloshinskii-Moriya interaction, leading to a sine-Gordon quantum Field theory, has been developed. Here we discuss many aspects of this subject in considerable detail, including a review of the $S=\frac{1}{2}$ chain in a Uniform Field, a spin-wave theory analysis of the Uniform plus staggered Field problem, exact amplitudes for the scaling of gap, staggered susceptibility and staggered magnetization with Field or temperature, intensities of soliton and breather peaks in the structure function, and Field and temperature dependence of the total susceptibility.
Ian Affleck - One of the best experts on this subject based on the ideXlab platform.
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Field induced gap in cu benzoate and other s 1 2 antiferromagnetic chains
Physical Review B, 1999Co-Authors: Ian Affleck, Masaki OshikawaAbstract:Recent experiments on the $S=\frac{1}{2}$ antiferromagnetic chain compound, Cu benzoate, discovered an unexpected gap scaling as approximately the $\frac{2}{3}$ power of an applied magnetic Field. A theory of this gap, based on an effective staggered Field, orthogonal to the applied Uniform Field, resulting from a staggered gyromagnetic tensor and a Dzyaloshinskii-Moriya interaction, leading to a sine-Gordon quantum Field theory, has been developed. Here we discuss many aspects of this subject in considerable detail, including a review of the $S=\frac{1}{2}$ chain in a Uniform Field, a spin-wave theory analysis of the Uniform plus staggered Field problem, exact amplitudes for the scaling of gap, staggered susceptibility and staggered magnetization with Field or temperature, intensities of soliton and breather peaks in the structure function, and Field and temperature dependence of the total susceptibility.
F Steglich - One of the best experts on this subject based on the ideXlab platform.
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the semimetallic s 1 2 antiferromagnetic chain yb4as3 quantum transfer matrix simulations and experimental Field dependent speciric heat data
Physica Status Solidi B-basic Solid State Physics, 2003Co-Authors: R Matysiak, G Kamieniarz, P Gegenwart, Hidekazu Aoki, A Ochiai, F SteglichAbstract:The S = 1/2 antiferromagnetic Heisenberg model with the Dzyaloshinsky-Moriya interaction is applied to Yb 4 As 3 . In this paper we calculate the specific heat of this model, mapped onto the isotropic Heisenberg model with both Uniform Field B x and staggered Field B y s , by the numerical quantum transfer-matrix (QTM) method and we present new experimental results for the polydomain sample in the applied Field.
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the semimetallic s 1 2 antiferromagnetic chain yb4as3 quantum transfer matrix simulations and experimental Field dependent specific heat data
Physica Status Solidi B-basic Solid State Physics, 2003Co-Authors: R Matysiak, G Kamieniarz, P Gegenwart, Hidekazu Aoki, A Ochiai, F SteglichAbstract:The S = 1/2 antiferromagnetic Heisenberg model with the Dzyaloshinsky-Moriya interaction is applied to Yb 4 As 3 . In this paper we calculate the specific heat of this model, mapped onto the isotropic Heisenberg model with both Uniform Field B x and staggered Field B y s , by the numerical quantum transfer-matrix (QTM) method and we present new experimental results for the polydomain sample in the applied Field.
Yoshiaki Sofue - One of the best experts on this subject based on the ideXlab platform.
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the primordial origin model of magnetic Fields in spiral galaxies
Publications of the Astronomical Society of Japan, 2010Co-Authors: Yoshiaki Sofue, Mami Machida, Takahiro KudohAbstract:We propose a primordial-origin model for composite configurations of global magnetic Fields in spiral galaxies. We show that a Uniform tilted magnetic Field wound up into a rotating disk galaxy can evolve into composite magnetic configurations comprising bisymmetric spiral (S = BSS), axisymmetric spiral (A = ASS), plane-reversed spiral (PR), and/or ring (R) Fields in the disk, and vertical (V) Fields in the center. By MHD simulations we show that these composite galactic Fields are indeed created from a weak primordial Uniform Field, and that different configurations can co-exist in the same galaxy. We show that spiral Fields trigger the growth of two-armed gaseous arms. The centrally accumulated vertical Fields are twisted and produce a jet toward the halo. We found that the more vertical was the initial Uniform Field, the stronger was the formed magnetic Field in the galactic disk.
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the primordial origin model of magnetic Fields in spiral galaxies
arXiv: Astrophysics of Galaxies, 2010Co-Authors: Yoshiaki Sofue, Mami Machida, Takahiro KudohAbstract:We propose a primordial-origin model for the composite configurations of global magnetic Fields in spiral galaxies. We show that Uniform tilted magnetic Field wound up into a rotating disk galaxy can evolve into composite magnetic configurations comprising bisymmetric spiral (S=BSS), axisymmetric spiral (A=ASS), plane-reversed spiral (PR), and/or ring (R) Fields in the disk, and vertical (V) Fields in the center. By MHD simulations we show that these composite galactic Fields are indeed created from weak primordial Uniform Field, and that the different configurations can co-exist in the same galaxy. We show that spiral Fields trigger the growth of two-armed gaseous arms. The centrally accumulated vertical Fields are twisted and produce jet toward the halo. We find that the more vertical was the initial Uniform Field, the stronger is the formed magnetic Field in the galactic disk.
Giselher Herzer - One of the best experts on this subject based on the ideXlab platform.
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random and Uniform anisotropy in soft magnetic nanocrystalline alloys invited
Journal of Magnetism and Magnetic Materials, 2010Co-Authors: Sybille Flohrer, Giselher HerzerAbstract:In amorphous and nanocrystalline transition metal based alloys with low magnetostriction, the soft magnetic properties are mainly determined by magneto-elastic and annealing-induced anisotropies which are Uniform on a scale much larger than the exchange correlation length. Though, in the nanocrystalline case, there are situations where the random magneto-crystalline anisotropy of the grains becomes relevant. The present paper surveys the interplay between the random magneto-crystalline and the Uniform Field-induced anisotropy in nanocrystalline FeCuNbSiB soft magnets. Typical examples where the contribution of the random anisotropy becomes particularly visible in the magnetic domain structure will be reviewed.
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interplay of Uniform and random anisotropy in nanocrystalline soft magnetic alloys
Acta Materialia, 2005Co-Authors: Sybille Flohrer, R Schafer, Christian Polak, Giselher HerzerAbstract:The magnetization process in nanocrystalline Fe73Cu1Nb3Si16B7 ribbons with different magnitudes of a magnetic Field induced transverse anisotropy was investigated by Kerr-microscopy and magnetic hysteresis measurements at room temperature and elevated temperatures. Comparing samples with strong (Ku 30 J/m 3 ) and weak (Ku 3 J/m 3 ) induced anisotropy Ku, we find significant differences in the magnetic microstructure, reflecting the interplay of the Uniform, Field induced and the random magnetocrystalline anisotropy. In particular for weak Ku, we find irregular magnetization patches within the wide regular domains connected to the induced anisotropy. These magnetization patches are fluctuating on the scale of a few micrometers and are interpreted in terms of the random anisotropy.
