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Related papers: Optimally Designed Digitally-Doped Mn:GaAs

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We discuss a possible form for a theory akin to local density functional theory, but able to produce van der Waals energies in a natural fashion. The usual Local Density Approximation (LDA) for the exchange and correlation energy $E_{xc}$…

Soft Condensed Matter · Physics 2007-05-23 John F. Dobson

Magnetic field dependent modulated microwave absorption (MMWA) measurements have been carried out to investigate vortex pinning effects in single crystals of the iron-based high-Tc superconductor Ba(Fe_{1-x}Co_x)_2As_2 with three different…

We demonstrate the electrical and optical control of ferromagnetism in semiconductor heterostructures at high temperatures of 100-117 K. The heterostructures consist of Mn delta-doped GaAs and p-type AlGaAs, where the overlap of the hole…

Materials Science · Physics 2007-05-23 Ahsan M. Nazmul , S. Kobayashi , S. Sugahara , M. Tanaka

The electronic structure and intrinsic magnetic properties of $\text{Fe}_2\text{AlB}_2$-related compounds and their alloys have been investigated using density functional theory. For $\text{Fe}_2\text{AlB}_2$, the crystallographic $a$ axis…

Materials Science · Physics 2017-03-22 Liqin Ke , Bruce N. Harmon , Matthew J. Kramer

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 report density functional calculations of the electronic structure and Fermi surface of the BaFe$_2$As$_2$ and LiFeAs phases including doping via the virtual crystal approximation. The results show that contrary to a rigid band picture,…

Superconductivity · Physics 2008-09-19 D. J. Singh

We study electron dynamics in a two-band delta-doped semiconductor within the envelope-function approximation. Using a simple parametrization of the confining potential arising from the ionized donors in the delta-doping layer, we are able…

Condensed Matter · Physics 2009-10-28 F. Dominguez-Adame

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

The calculation of electronic properties of materials is an important task of solid state theory, albeit particularly difficult if electronic correlations are strong, for example in transition metals, their oxides and in f-electron systems.…

Strongly Correlated Electrons · Physics 2009-09-29 K. Held

Applying the local density approximation (LDA) and dynamical mean field theory (DMFT) to paramagnetic $\alpha $-iron, we revisit a problem of theoretical description of its magnetic properties. The analysis of local magnetic susceptibility…

Strongly Correlated Electrons · Physics 2015-05-19 P. A. Igoshev , A. V. Efremov , A. A. Katanin

Most applications of time-dependent density-functional theory (TDDFT) use the adiabatic local-density approximation (ALDA) for the dynamical exchange-correlation potential Vxc(r,t). An exact (i.e., nonadiabatic) extension of the…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 C. A. Ullrich

The lack of p-type doping has impeded the development of vertical gallium oxide (Ga2O3) devices. Current blocking layers (CBL) using implanted deep acceptors has been used to demonstrate vertical devices. This paper presents the first…

Polarisation doping of Al$_x$Ga$_{1-x}$N, through grading of $x$, has realised major improvements in $p$-type conductivity in ultraviolet (UV) light-emitting diodes (LEDs) compared to conventional impurity doping. However, the exact balance…

We probe the real space electronic response to a local magnetic impurity in isovalent and heterovalent doped BaFe2As2 (122) using Nuclear Magnetic Resonance (NMR). The local moments carried by Mn impurities doped into…

Superconductivity · Physics 2021-11-24 D. LeBoeuf , Y. Texier , M. Boselli , A. Forget , D. Colson , J. Bobroff

The LDA+DMFT approach merges conventional band structure theory in the local density approximation (LDA) with a state-of-the-art many-body technique, the dynamical mean-field theory (DMFT). This new computational scheme has recently become…

Strongly Correlated Electrons · Physics 2009-10-31 K. Held , I. A. Nekrasov , N. Blümer , V. I. Anisimov , D. Vollhardt

Nominally 45 nm GaN:Mg/ 5 nm (Ga,Mn)N / 45 nm GaN:Mg trilayers structures prepared by molecular beam epitaxy on GaN-buffered Al2O3 substrates are investigated to verify whether the indirect co-doping by holes from the cladding layers can…

Materials Science · Physics 2021-02-25 Katarzyna Gas , Gerd Kunert , Piotr Dluzewski , Rafal Jakiela , Detlef Hommel , Maciej Sawicki

Recently, Tao and Mo (TM) proposed an accurate all-purpose nonempirical meta-generalized gradient approximation (meta-GGA). The exchange part was derived from the density matrix approximation, while the correlation part is based on a…

Materials Science · Physics 2017-06-28 Yuxiang Mo , Guocai Tian , Jianmin Tao

We model the exchange-correlation (XC) energy density of the Si crystal and atom as calculated by variational Monte Carlo (VMC) methods with a gradient analysis beyond the local density approximation (LDA). We find the Laplacian of the…

Materials Science · Physics 2009-11-11 Antonio C. Cancio , M. Y. Chou

We report the first evidence of electron-mediated ferromagnetism in a molecular-beam-epitaxy (MBE) grown $GaAs/Al_{0.3}Ga_{0.7}As$ heterostructure with Mn $\delta$-doping. The interaction between the magnetic dopants (Mn) and the…

Mesoscale and Nanoscale Physics · Physics 2008-07-02 A. Bove , F. Altomare , N. B. Kundtz , Albert M. Chang , Y. J. Cho , X. Liu , J. Furdyna

Standard approximations for the exchange-correlation (XC) functional in Kohn-Sham density functional theory (KS-DFT) typically lead to unacceptably large errors when applied to strongly-correlated electronic systems. Partition-DFT (PDFT) is…

Chemical Physics · Physics 2023-09-12 Yi Shi , Yuming Shi , Adam Wasserman