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Related papers: Onset of ferromagnetism in low-doped GaMnAs

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The interplay between disorder and spin polarization in a GaMnAs thin layer results into spin-polarized impurity hole bands. A figure of merit is defined to label the hole state as being extended or localized. The calculation leads to a…

Materials Science · Physics 2016-09-08 E. Dias Cabral , M. A. Bosellli , A. T. da Cunha Lima , I. C. da Cunha Lima

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…

Disordered Systems and Neural Networks · Physics 2015-06-24 Georges Bouzerar , Timothy Ziman , Josef Kudrnovsky

Considerable efforts have been devoted recently to synthesize diluted magnetic semiconductors having ferromagnetic properties at room temperature because of their technological impacts for spintronic devices. In 2001 successful growth of…

A density functional theory of ferromagnetism in heterostructures of compound semiconductors doped with magnetic impurities is presented. The variable functions in the density functional theory are the charge and spin densities of the…

Condensed Matter · Physics 2009-11-07 J. Fernandez-Rossier , L. J. Sham

We report on a comprehensive combined experimental and theoretical study of Curie temperature trends in (Ga,Mn)As ferromagnetic semiconductors. Broad agreement between theoretical expectations and measured data allows us to conclude that…

We present a quantitative theory for the effects of correlated doping on the ferromagnetism of diluted magnetic semiconductors. It predicts that room temperature ferromagnetism should be possible in homogeneous, but correlated, samples of…

Disordered Systems and Neural Networks · Physics 2007-05-23 Georges Bouzerar , Timothy Ziman , Josef Kudrnovsky

In the framework of the diagrammatic method with self-consistent field, the maximum on the temperature dependence of the susceptibility of a weakly doped narrow-band Hubbard magnet below the Curie temperature $T_{\rm C}$ is predicted. By…

Strongly Correlated Electrons · Physics 2010-06-07 E. E. Zubov

Various experimental results providing information on thermodynamic density of states in (Ga,Mn)As are analyzed theoretically assuming that holes occupy GaAs-like valence bands. Allowing for Gaussian fluctuations of magnetization, the…

Materials Science · Physics 2011-07-29 C. Sliwa , T. Dietl

The ferromagnetic semiconductor (Ga,Mn)As has emerged as the most studied material for prototype applications in semiconductor spintronics. Because ferromagnetism in (Ga,Mn)As is hole-mediated, the nature of the hole states has direct and…

Materials Science · Physics 2012-03-09 M. Dobrowolska , K. Tivakornsasithorn , X. Liu , J. K. Furdyna , M. Berciu , K. M. Yu , W. Walukiewicz

We provide experimental evidence that the upper limit of ~110 K commonly observed for the Curie temperature T_C of Ga(1-x)Mn(x)As is caused by the Fermi-level-induced hole saturation. Ion channeling, electrical and magnetization…

Materials Science · Physics 2009-11-10 K. M. Yu , W. Walukiewicz , T. Wojtowicz , W. L. Lim , X. Liu , U. Bindley , M. Dobrowolska , J. K. Furdyna

Comment on the recent Nature Materials article by M. Dobrowolska et al., arXiv:1203.1852. We present experimental data showing that the Curie temperature and conductivity of high quality (Ga,Mn)As samples are maximized at low compensation,…

We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes localized in a Mn-derived band. For x<0.06, infrared absorption and photoconductivity spectra indicate the presence of a Mn impurity band which is not merged with…

Materials Science · Physics 2009-11-11 M. A. Scarpulla , B. L. Cardozo , W. M. Hlaing Oo , M. D. McCluskey , O. D. Dubon

Taking into account both random impurity distribution and thermal fluctuations of localized spins, we have performed a model calculation for the carrier (hole) state in Ga$_{1-x}$Mn$_x$As by using the coherent potential approximation (CPA).…

Materials Science · Physics 2009-11-07 M. Takahashi , K. Kubo

We investigate the relationship between the Curie temperature TC and the carrier density p in the ferromagnetic semiconductor (Ga,Mn)As. Carrier densities are extracted from analysis of the Hall resistance at low temperatures and high…

Mesoscale and Nanoscale Physics · Physics 2013-03-12 M. Wang , K. W. Edmonds , B. L. Gallagher , A. W. Rushforth , O. Makarovsky , A. Patanè , R. P. Campion , C. T. Foxon , V. Novak , T. Jungwirth

For the prototype diluted ferromagnetic semiconductor (Ga,Mn)As, there is a fundamental concern about the electronic states near the Fermi level, i.e., whether the Fermi level resides in a well-separated impurity band derived from Mn doping…

We theoretically investigate impurity correlation and magnetic clustering effects on the long-range ferromagnetic ordering in diluted magnetic semiconductors, such as $\textrm{Ga}_{1-x}\textrm{Mn}_{x}\textrm{As}$, using analytical arguments…

Materials Science · Physics 2009-11-11 D. J. Priour , S. Das Sarma

Electronic structures, exchange interaction mechanism between magnetic ions and Curie temperature of Vanadium - doped Nitrides (AlN, GaN, and InN) are studied within KKR-LSDA-CPA. It is found that the ferromagnetic super-exchange…

Materials Science · Physics 2008-01-10 V. A. Dinh , H. Katayama-Yoshida

We present a theoretical survey of ferromagnetic transition temperatures in cubic (III,Mn)V semiconductors based on a model with $S=5/2$ local moments exchange-coupled to itinerant holes in the host semiconductor valence band. Starting from…

Materials Science · Physics 2016-08-16 T. Jungwirth , Jürgen König , Jairo Sinova , J. Kučera , A. H. MacDonald

A remarkable progress towards functional ferromagnetic semiconductor materials for spintronics has been achieved in p-type (Ga,Mn)As. Robust hole-mediated ferromagnetism has, however, been observed also in other III-V hosts such as…

We present a theory to model carrier mediated ferromagnetism in concentrated or diluted local moment systems. The electronic subsystem of the Kondo lattice model is described by a combined equation of motion / coherent potential…

Strongly Correlated Electrons · Physics 2011-04-22 M. Stier , W. Nolting
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