中文
相关论文

相关论文: Magnetic-field effects in defect-controlled ferrom…

200 篇论文

We consider a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds to discuss the dependence of the hole density on that of Mn sites in Ga_{1-x}Mn_xAs. The hole concentration, p, as a function of…

材料科学 · 物理学 2009-11-07 Raimundo R. dos Santos , Luiz E. Oliveira , J. d'Albuquerque e Castro

We employ the dynamical mean field approximation to perform a systematic study of magnetism in Ga_{1-x}Mn_xAs. Our model incorporates the effects of the strong spin-orbit coupling on the J=3/2 GaAs valence bands and of the exchange…

强关联电子 · 物理学 2007-05-23 K. Aryanpour , J. Moreno , M. Jarrell , R. S. Fishman

We have studied the field dependence of the magnetization in epilayers of the diluted magnetic semiconductor Ga(1-x)Mn(x)As for 0.0135 < x < 0.083. Measurements of the low temperature magnetization in fields up to 3 T show a significant…

凝聚态物理 · 物理学 2009-11-07 S. J. Potashnik , K. C. Ku , S. H. Chun , R. F. Wang , M. B. Stone , N. Samarth , P. Schiffer

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…

材料科学 · 物理学 2009-11-07 S. Das Sarma , E. H. Hwang , A. Kaminski

Ion implantation of Mn combined with pulsed laser melting is employed to obtain two representative compounds of dilute ferromagnetic semiconductors (DFSs): Ga1-xMnxAs and In1-xMnxAs. In contrast to films deposited by the widely used…

We investigate the effect of quantum confinement on the ferromagnetism of diluted magnetic semiconductor Ga$_{1-x}$Mn$_x$As using a combination of tight-binding and density functional methods. We observe strong majority-spin Mn $d$-As $p$…

材料科学 · 物理学 2015-06-24 Sameer Sapra , D. D. Sarma , S. Sanvito , N. A. Hill

We show that suitably-designed magnetic semiconductor heterostructures consisting of Mn delta-doped GaAs and p-type AlGaAs layers, in which the locally high concentration of magnetic moments of Mn atoms are controllably overlapped with the…

材料科学 · 物理学 2009-11-11 A. M. Nazmul , T. Amemiya , Y. Shuto , S. Sugahara , M. Tanaka

We report on the magnetic and the electronic properties of the prototype dilute magnetic semiconductor Ga$_{1-x}$Mn$_x$As using infrared (IR) spectroscopy. Trends in the ferromagnetic transition temperature $T_C$ with respect to the IR…

We have performed ab initio calculations within the density-functional theory for Ga_{1-x}Mn_xAs diluted semiconductors. Total energy results unambiguously show that a quasi-localized down-spin hole, with strong p-like character, surrounds…

材料科学 · 物理学 2007-05-23 A. J. R. da Silva , A. Fazzio , R. R. dos Santos , L. E. Oliveira

We perform a theoretical study, using {\it ab initio} total energy density-functional calculations, of the effects of disorder on the $Mn-Mn$ exchange interactions for $Ga_{1-x}Mn_xAs$ diluted semiconductors. For a 128 atoms supercell, we…

材料科学 · 物理学 2009-11-11 Antonio J. R. da Silva , A. Fazzio , Raimundo R. dos Santos , Luiz E. Oliveira

We report on a comprehensive study of the ferromagnetic moment per Mn atom in (Ga,Mn)As ferromagnetic semiconductors. Theoretical discussion is based on microscopic calculations and on an effective model of Mn local moments…

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…

强关联电子 · 物理学 2009-11-07 A. Chattopadhyay , S. Das Sarma , A. J. Millis

We present a theoretical study of (Ga,Mn)(As,C) diluted magnetic semiconductors with high C acceptor density that combines insights from phenomenological model and microscopic approaches. A tight-binding coherent potential approximation is…

材料科学 · 物理学 2007-05-23 T. Jungwirth , J. Masek , Jairo Sinova , A. H. MacDonald

The magnetic properties of the diluted magnetic semiconductor Ga_{1-x}Mn_{x}As are studied within the dynamical cluster approximation. We use the k-dot-p Hamiltonian to describe the electronic structure of GaAs with spin-orbit coupling and…

强关联电子 · 物理学 2015-05-14 Unjong Yu , Abdol-Madjid Nili , Karlis Mikelsons , Brian Moritz , Juana Moreno , Mark Jarrell

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…

The measurement of the hole density in the ferromagnetic semiconductor Ga$_{1-x}$Mn$_{x}$As is notoriously difficult using standard transport techniques due to the dominance of the anomalous Hall effect. Here, we report the first…

材料科学 · 物理学 2009-11-07 M. J. Seong , S. H. Chun , Hyeonsik M. Cheong , N. Samarth , A. Mascarenhas

We compare experimental resistivity data on Ga_{1-x}Mn_xAs films with theoretical calculations using a scaling theory for strongly disordered ferromagnets. All characteristic features of the temperature dependence of the resistivity can be…

材料科学 · 物理学 2015-05-13 C. P. Moca , B. L. Sheu , N. Samarth , P. Schiffer , B. Janko , G. Zarand

We investigate the current debate on the Mn valence in Ga$_{1-x}$Mn$_x$N, a diluted magnetic semiconductor (DMSs) with a potentially high Curie temperature. From a first-principles Wannier-function analysis, we unambiguously find the Mn…

材料科学 · 物理学 2015-11-13 Ryky Nelson , Tom Berlijn , Juana Moreno , Mark Jarrell , Wei Ku

Molecular beam epitaxy has been employed to obtain Ga1-xMnxN films with x up to 10% and Curie temperatures T_C up to 13 K. The magnitudes of T_C and their dependence on x, T_C(x) ~ x^m, where m = 2.2 +/- 0.2 are quantitatively described by…

The magneto-optical properties of the ferromagnetic semiconductor Ga$_{1-x}$Mn$_{x}$As are studied within the dynamical mean-field approximation (DMFA). A material-specific multiband $sp^{3}$ tight-binding Hamiltonian is employed for the…

强关联电子 · 物理学 2010-07-28 A. -M. Nili , U. Yu , J. Moreno , D. Browne , M. Jarrell
‹ 上一页 1 2 3 10 下一页 ›