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Related papers: Paramagnetic-ferromagnetic transition in a double-…

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Applying the local density and dynamical mean field approximations to paramagnetic \gamma-iron we revisit the problem of theoretical description of magnetic properties in a wide temperature range. We show that contrary to \alpha-iron, the…

Strongly Correlated Electrons · Physics 2013-10-29 P. A. Igoshev , A. V. Efremov , A. I. Poteryaev , A. A. Katanin , V. I. Anisimov

Thin electrodes of magnetic tunnel junctions can show superparamagnetism at surprisingly low temperature. We analysed their thermally induced switching for varying temperature, magnetic and electric field. Although the dwell times follow an…

Mesoscale and Nanoscale Physics · Physics 2019-09-23 G. Reiss , J. Ludwig , K. Rott

The magnetic properties of a variety of materials with promise for technological applications have been described by models in which fermions are coupled to local moment spins. Monte Carlo studies of such models usually ignore…

Strongly Correlated Electrons · Physics 2011-05-04 Nuri A. Yazdani , Malcolm P. Kennett

Doping change and distortion effect on the double-exchange ferromagnetism are studied within a simplified double-exchange model. The presence of distortion is modelled by introducing the Falicov-Kimball interaction between itinerant…

Strongly Correlated Electrons · Physics 2007-05-23 Phan Van-Nham , Tran Minh-Tien

We present a general framework to describe the simultaneous para-to-ferromagnetic and semiconductor-to-metal transition in electron-doped EuO. The theory correctly describes detailed experimental features of the conductivity and of the…

Strongly Correlated Electrons · Physics 2008-02-02 Michael Arnold , Johann Kroha

In a diluted magnetic semiconductor system, the exchange interaction between magnetic impurities has two independent components: a direct antiferromagnetic interaction and a ferromagnetic interaction mediated by charge carriers. Depending…

Disordered Systems and Neural Networks · Physics 2009-11-10 A. Kaminski , Victor Galitski , S. Das Sarma

We compute the real and imaginary parts of the electric permittivities and magnetic permeabilities for relativistic electrons from quantum electrodynamics at finite temperature and density. A semiclassical approximation establishes the…

Quantum Physics · Physics 2018-03-14 C. A. A. de Carvalho

We study the low energy properties of the one-orbital quantum double-exchange model by using the slave fermion formulation. We construct a mean-field theory which gives a simple explanation for the magnetic and thermodynamic properties of…

Strongly Correlated Electrons · Physics 2007-05-23 Yu-Li Lee , Yu-Wen Lee

We connect between the problem of thermodynamics of localized magnetic moments in a Dirac semimetal, the interaction with relativistic electrons leading to the effective ferromagnetic exchange between the moments, and the existing theories…

Mesoscale and Nanoscale Physics · Physics 2016-07-26 Eugene Kogan , Moshe Kaveh

We present a thorough analysis of the electron density distribution (shape) of two electrons, confined in the three-dimensional harmonic oscillator potential, as a function of the perpendicular magnetic field.Explicit algebraic expressions…

Mesoscale and Nanoscale Physics · Physics 2018-03-20 N. S. Simonovic , R. G. Nazmitdinov

We consider spin-fermion systems which get their magnetic properties from a system of localized magnetic moments being coupled to conducting electrons. The dynamical degrees of freedom are spin-$s$ operators of localized spins and spin-1/2…

Strongly Correlated Electrons · Physics 2009-11-13 Naoum Karchev

We study in this paper the phase transition in superlattices formed by alternate magnetic and ferroelectric layers, by the use of Monte Carlo simulation. We study effects of temperature, external magnetic and electric fields,…

Statistical Mechanics · Physics 2019-02-20 Ildus F. Sharafullin , M. Kh. Kharrasov , H. T. Diep

A microscopic mean-field theory of the phase coexistence between ferromagnetism and superconductivity in the weakly ferromagnetic itinerant electron system is constructed, while incorporating a realistic mechanism for superconducting…

Strongly Correlated Electrons · Physics 2007-05-23 Andriy H. Nevidomskyy

We present a generalization of the spin-fluctuation theory of magnetism which allows us to treat the full rotational invariance of the exchange interaction. The approach is formulated in terms of the local density approximation plus…

Strongly Correlated Electrons · Physics 2012-09-26 V. I. Anisimov , A. S. Belozerov , A. I. Poteryaev , I. Leonov

The macroscopic magnetizations of a RuSr2(Eu0.7Ce0.3)2Cu2O10+d sample were investigated. A ferromagnet-like transition occurs around T_M in the low-field magnetization. Highly nonlinear M(H), non-Curie-Weiss susceptibility, and slow…

Superconductivity · Physics 2009-11-07 Y. Y. Xue , B. Lorenz , D. H. Cao , C. W. Chu

Electron spectrum of 2D and 3D antiferromagnetic metals is calculated with account of spin-fluctuation corrections within perturbation theory in the s-f exchange model. Effects of the interaction of conduction electrons with spin waves in…

Strongly Correlated Electrons · Physics 2009-10-31 V. Yu. Irkhin , M. I. Katsnelson

The metamagnetic transition between the antiferromagnetic and paramagnetic state in UIrGe has been studied at various temperatures by magnetization, heat capacity and magnetocaloric-effect measurements on a single crystal in static and…

We explore the derivation of interatomic exchange interactions in ferromagnets within density-functional theory (DFT) and the mapping of DFT results onto a spin Hamiltonian. We delve into the problem of systems comprising atoms with strong…

Materials Science · Physics 2013-10-10 Marjana Lezaic , Phivos Mavropoulos , Gustav Bihlmayer , Stefan Blügel

We use a numerically exact real-time path integral Monte Carlo scheme to compute electron transfer dynamics between two redox sites within a spin-boson approach. The case of asymmetric reactions is studied in detail in the least understood…

Condensed Matter · Physics 2009-11-10 L. Muehlbacher , R. Egger

We present a general thermodynamic theory that describes phases and phase transitions of ferromagnetic superconductors with spin-triplet electron Cooper pairing. The theory is based on extended Ginzburg-Landau expansion in powers of…

Superconductivity · Physics 2016-09-08 Diana V. Shopova , Dimo I. Uzunov