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相关论文: \textit{Additional} carrier-mediated ferromagnetis…

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In numerous diluted magnetic semiconductor (DMS) systems, the competition takes place between the short-range antiferromagnetic (AF) superexchange interactions and the long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling mediated by the…

材料科学 · 物理学 2016-10-04 K. Szalowski

Indirect exchange coupling in magnetic multilayers, also known as the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, is known to be highly effective in controlling the interlayer alignment of the magnetization. This coupling is typically…

A lattice spin-fermion model for diluted magnetic semiconductors (DMS) is investigated numerically, improving on previously used mean-field (MF) approximations. Curie temperatures are obtained varying the Mn-spin x and hole n densities, and…

强关联电子 · 物理学 2009-11-07 Gonzalo Alvarez , Matthias Mayr , Elbio Dagotto

We investigate the influence of degeneracies of the conduction band and the $f$-orbital on the stability of ferromagnetism in the periodic Anderson model. To this end we calculate the temperature dependence of the inverse susceptibility for…

强关联电子 · 物理学 2009-11-13 Unjong Yu , Krzysztof Byczuk , Dieter Vollhardt

The magnetic properties of dilute magnetic semiconductors (DMS) are calculated from first-principles by mapping the ab initio results on a classical Heisenberg model. It is found that the range of the exchange interaction in (Ga, Mn)N is…

材料科学 · 物理学 2007-05-23 K. Sato , W. Schweika , P. H. Dederichs , H. Katayama-Yoshida

We use the local density approximation (LDA) and LDA+U schemes to study the magnetism of (GaMn)As and (GaMn)N for a number of Mn concentrations and varying number of holes. We show that for both systems and both calculational schemes the…

材料科学 · 物理学 2009-11-10 L. M. Sandratskii , P. Bruno , J. Kudrnovský

We study the interatomic exchange interactions and Curie temperatures in half-metallic semi Heusler compounds NiCrZ (Z=P, Se, Te) and NiVAs. The study is performed within the framework of density functional theory. The calculation of…

材料科学 · 物理学 2015-06-25 E. Sasioglu , L. M. Sandratskii , P. Bruno

A detailed study of the paramagnetic to ferromagnetic phase transition in the one-band Hubbard model in the presence of binary alloy disorder is presented. The influence of the disorder (with concentration $x$ and $1-x$ of the two alloy…

强关联电子 · 物理学 2009-11-07 Krzysztof Byczuk , Martin Ulmke , Dieter Vollhardt

Employing first-principles electronic structure calculations in conjunction with the frozen-magnon method we study the effective exchange interactions and spin waves in local moment ferromagnets. As prototypes we have chosen three…

材料科学 · 物理学 2012-10-30 I. Galanakis , E. Sasioglu

Magnetism of the spin-$\frac12$ $\alpha$-KVOPO$_4$ is studied by thermodynamic measurements, $^{31}$P nuclear magnetic resonance (NMR), neutron diffraction, and density-functional band-structure calculations. Ferromagnetic Curie-Weiss…

We present a semi-analytic theory for the Curie temperature in diluted magnetic semi-conductors that treats disorder effects exactly in the effective Heisenberg Hamiltonian, and spin fluctuations within a local RPA. The exchange couplings…

无序系统与神经网络 · 物理学 2015-06-24 Georges Bouzerar , Timothy Ziman , Josef Kudrnovsky

We propose an explanation of the anomalous growth of plasticity in ferromagnets near the Curie point. We demonstrate that this effect is caused by spin-dependent detachment of dislocations from obstacles under an influence of the internal…

材料科学 · 物理学 2009-11-07 M. Molotskii , V. Fleurov

Magnetic two-dimensional materials have potential application in next-generation electronic devices and have stimulated extensive interest in condensed matter physics and material fields. However, how to realize high-temperature…

材料科学 · 物理学 2024-06-19 Panjun Feng , Shuo Zhang , Dapeng Liu , Miao Gao , Fengjie Ma , Xun-Wang Yan , Z. Y. Xie

In this pedagogical paper, the comparative analysis of two common approaches describing the ferromagnetic phase transition in diluted magnetic semiconductors (DMS) is expounded in terms of Weiss field approximation. Assuming a finite spin…

材料科学 · 物理学 2021-07-20 Y. G. Semenov , S. M. Ryabchenko

The temperature dependence of magnetization and specific heat of the ferromagnetic compound DyFe2Zn20 has been measured in detail in various magnetic fields. We have observed anomalous magnetic behavior, i.e., a strong anisotropy at 2 K,…

We study whether Fermi-surface (FS) nesting can give rise to high-temperature superconductivity in iron pnictides. Starting with ab initio construction of an effective four-orbital model, we employ the fluctuation-exchange approximation to…

超导电性 · 物理学 2015-05-14 Ryotaro Arita , Hiroaki Ikeda

The metal-graphene contact resistance is one of the major limiting factors toward the technological exploitation of graphene in electronic devices and sensors. A high contact resistance can be detrimental to device performance and spoil the…

In the present work ferromagnetic ordering in the Hubbard model generalized by taking into account the inter-atomic exchange interaction and correlated hopping in partially filled narrow band is considered. Expressions for the magnetization…

凝聚态物理 · 物理学 2007-05-23 L. Didukh

The electronic properties, exchange interactions, finite-temperature magnetism, and transport properties of random quaternary Heusler Ni$_{2}$MnSn alloys doped with Cu- and Pd-atoms are studied theoretically by means of {\it ab initio}…

材料科学 · 物理学 2015-05-19 S. K. Bose , J. Kudrnovský , V. Drchal , I. Turek

We study experimentally and theoretically the effects of disorder, nonlinear screening, and magnetism in semiconductor heterostructures containing a $\delta$-layer of Mn, where the charge carriers are confined within a quantum well and…

介观与纳米尺度物理 · 物理学 2013-05-29 Vikram Tripathi , Kusum Dhochak , B. A. Aronzon , V. V. Rylkov , A. B. Davydov , Bertrand Raquet , Michel Goiran , K. I. Kugel