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Related papers: Magnetic spin excitations in Mn doped GaAs : A mod…

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The low-temperature spin dynamics of doped manganites have been analyzed within a tight-binding model, the parameters of which are estimated by mapping the results of ab initio density functional calculations onto the model. This approach…

Materials Science · Physics 2009-10-31 Priya Mahadevan , I. V. Solovyev , K. Terakura

The magnetic and electrical transport properties of Mn-doped amorphous silicon (\textit{a-}Mn$_{x}$Si$_{1-x}$) thin films have been measured. The magnetic susceptibility obeys the Curie-Weiss law for a wide range of $x$ (0.005-0.175) and…

Materials Science · Physics 2007-06-20 Li Zeng , E. Helgren , R. Islam , B. J. Wilkens , R. J. Culbertson , David J. Smith , F. Hellman

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

The electronic structure of doped Mn in (Ga,Mn)As is studied by resonant inelastic X-ray scattering (RIXS). From configuration-interaction cluster-model calculations, the line shapes of the Mn $L_3$ RIXS spectra can be explained by $d$-$d$…

Materials Science · Physics 2015-08-06 M. Kobayashi , H. Niwa , Y. Takeda , A. Fujimori , Y. Senba , H. Ohashi , A. Tanaka , S. Ohya , P. N. Hai , M. Tanaka , Y. Harada , M. Oshima

The magnetic properties and the electronic excitations of the new diluted magnetic semiconductor Ba$_{1-x}$K$_{x}$(Zn$_{1-y}$Mn$_{y}$)$_{2}$As$_{2}$ have been studied by x-ray magnetic circular dichroism (XMCD) and resonant inelastic x-ray…

We calculate magnetization in magnetically doped semiconductors assuming a local exchange model of carrier-mediated ferromagnetic mechanism and using a number of complementary theoretical approaches. In general, we find that the results of…

Materials Science · Physics 2009-11-07 S. Das Sarma , E. H. Hwang , A. Kaminski

We have used time-of-flight inelastic neutron scattering to measure the spin wave spectrum of the canonical half-doped manganite Pr$_{0.5}$Ca$_{0.5}$MnO$_{3}$, in its magnetic and orbitally ordered phase. The data, which cover multiple…

Strongly Correlated Electrons · Physics 2016-07-25 R. A. Ewings , T. G. Perring , O. Sikora , D. L. Abernathy , Y. Tomioka , Y. Tokura

The electronic structure of Mn doped GaAs and GaN have been examined within a multiband Hubbard model. By virtue of the positioning of the Mn d states, Mn doped GaAs is found to belong to the p-d metal regime of the Zaanen-Sawatzky-Allen…

Materials Science · Physics 2017-08-02 Basudeb Mandal , Hirak Kumar Chandra , Priya Mahadevan

We formulate a theory of doped magnetic semiconductors such as Ga$_{1-x}$Mn$_x$As which have attracted recent attention for their possible use in spintronic applications. We solve the theory in the dynamical mean field approximation to find…

Strongly Correlated Electrons · Physics 2009-11-07 A. Chattopadhyay , S. Das Sarma , A. J. Millis

Based on ab initio calculations of Ga_{1-x}Mn_xN_yAs_{1-y} and Ga_{1-x}Mn_xC_yAs_{1-y}, we propose a new codoping method to enhance the Curie temperature T_c of diluted magnetic semiconductors. The solubility of Mn can be increased up to…

Materials Science · Physics 2008-01-15 Van An Dinh , K. Sato , H. Katayama-Yoshida

We study the optical conductivity in the III-V diluted magnetic semiconductor GaMnAs and compare our calculations to available experimental data. Our model study is able to reproduce both qualitatively and quantitatively the observed…

Disordered Systems and Neural Networks · Physics 2015-05-18 Georges Bouzerar , Richard Bouzerar

Electrical transport properties of DyAs epitaxial layers grown on GaAs have been investigated at various temperatures and magnetic fields up to 12T. The measured longitudinal resistances show two distinct peaks at fields around 0.2 and 2.5T…

Condensed Matter · Physics 2009-10-31 J. M. Mao , M. E. Zudov , R. R. Du , P. P. Lee , L. P. Sadwick , R. J. Hw

First principles total-energy pseudopotential calculations have been performed to investigate STM images of the (110) cross-sectional surface of Mn-doped GaAs. We have considered configurations with Mn in interstitial positions in the…

Materials Science · Physics 2007-05-23 A. Stroppa

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 use femtosecond optical pulses to induce, control and monitor magnetization precession in ferromagnetic Ga0.965Mn0.035As. At temperatures below ~40 K we observe coherent oscillations of the local Mn spins, triggered by an ultrafast…

Materials Science · Physics 2009-11-13 J. Qi , Y. Xu , N. Tolk , X. Liu , J. K. Furdyna , I. E. Perakis

Doped and undoped manganites are modeled by the coupling between itinerant $e_g$ electrons and static $t_{2g}$ spins, the Jahn-Teller and breathing phonon modes, and the Coulomb interaction. We provide for a careful estimate of all…

Strongly Correlated Electrons · Physics 2013-05-29 Y. -F. Yang , K. Held

Collective excitations in magnetic materials can be investigated by means of inelastic neutron scattering. We show that this experimental method gives access to the complete spectrum of magnetic fluctuations through the energy- and…

Strongly Correlated Electrons · Physics 2007-05-23 B. Roessli , P. Böni

We review recently developed two-step approach for description of electronic and magnetic properties of a new class of materials, the diluted magnetic semiconductors. In the first step we construct, on the basis of the state-of-the-art…

Materials Science · Physics 2007-07-23 Josef Kudrnovský , V. Drchal , Georges Bouzerar , Richard Bouzerar

The discovery of ferromagnetism in Mn doped GaAs [1] has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices [2-4]. A major hurdle for realistic…

Materials Science · Physics 2009-11-11 Dale Kitchen , Anthony Richardella , Jian-Ming Tang , Michael E. Flatte , Ali Yazdani

We report the results of ab initio molecular dynamics simulations of liquid Ga_xAs_{1-x} alloys at five different concentrations, at a temperature of 1600 K, just above the melting point of GaAs. The liquid is predicted to be metallic at…

Condensed Matter · Physics 2009-10-31 R. V. Kulkarni , D. Stroud