相关论文: Dynamics of diluted magnetic semiconductors from a…
The sign, magnitude, and range of the exchange couplings between pairs of Mn ions is determined for (Ga,Mn)N and (Ga,Mn)N:Si with x < 3%. The samples have been grown by metalorganic vapor phase epitaxy and characterized by secondary-ion…
We present results of tight-binding spin-dynamics simulations of individual and pairs of substitutional Mn impurities in GaAs. Our approach is based on the mixed quantum-classical scheme for spin dynamics, with coupled equations of motions…
We demonstrate that the magnetization in magnetic semiconductors exhibits nutational motion when subjected to an external magnetic field. This behavior originates from the splitting of the conduction-electron band which induces anisotropic,…
The low temperature dynamics of the two- and three-dimensional Ising spin glass model with Gaussian couplings is investigated via extensive Monte Carlo simulations. We find an algebraic decay of the remanent magnetization. For the…
The magnetization dynamics in diluted magnetic semiconductor heterostructures based on (Zn,Mn)Se and (Cd,Mn)Te has been studied experimentally by optical methods and simulated numerically. In the samples with nonhomogeneous magnetic ion…
In III-V dilute magnetic semiconductors (DMSs) such as Ga$_{1-x}$Mn$_x$As, the impurity positions tend to be correlated, which can drastically affect the electronic transport properties of these materials. Within the memory function…
Ferromagnetic semiconductors promise the extension of metal-based spintronics into a material system that combines widely tunable electronic, optical, and magnetic properties. Here, we take steps towards realizing that promise by achieving…
In this paper the magnetic behaviour of SmFeAsO and SmFeAs(O0.85F0.15) samples is presented and discussed. Molar susceptibility of SmFeAsO exhibits a local peak at T around 140K due to the establishment of a long range antiferromagnetic…
The field-cooled magnetization (FCM) processes of Ising spin glasses under relatively small fields are investigated by experiment on Fe_{0.55}Mn_{0.45}TiO_3 and by numerical simulation on the three-dimensional Edwards-Anderson model. Both…
(Ga,Mn)As and related diluted magnetic semiconductors play a major role in spintronics research because of their potential to combine ferromagnetism and semiconducting properties in one physical system. Ferromagnetism requires ~1-10% of…
Non-thermal laser induced spin excitations, recently discovered in conventional oxide and metal ferromagnets, open unprecedented opportunities for research and applications of ultrafast optical manipulation of magnetic systems.…
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…
The spin structure in a magnetic dot, which is an example of a quantum few-body system, is studied as a function of exchange coupling strength and dot size with in the semiclassical approximation on a discrete lattice. As the exchange…
Dielectric and magnetic properties have been studied for poly-crystalline samples of quasi-one-dimensional frustrated spin-1/2 system Rb$_{2}$(Cu$_{1-x}$M$_{x}$)$_{2}$Mo$_{3}$O$_{12}$(M=Ni and Zn) which does not exhibit a three-dimensional…
We investigated the nature of the magnetic phase transition in the Ge/1-x-y/Sn/x/Mn/y/Te mixed crystals with chemical composition changing in the range of 0.083 < x < 0.142 and 0.012 < y < 0.119. The DC magnetization measurements performed…
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…
The magnetic, transport, and structural properties of (Ga,Cr)As are reported. Zincblende Ga$_{1-x}$Cr$_{x}$As was grown by low-temperature molecular beam epitaxy (MBE). At low concentrations, x$\sim$0.1, the materials exhibit unusual…
We study energetic, magnetic, and electronic properties of diluted substitutional Mn-pairs on the reconstructed $(001)$ GaAs surfaces. The studies are based on first-principles calculations in the framework of the density functional theory.…
We investigate the magnetic properties of a range of low-dimensional ferromagnets using a combination of first-principles calculations and atomistic spin dynamics simulations. This approach allows us to evaluate the ground state and finite…
In this paper, we discuss magnetic properties of dilute systems of localized spins interacting with itinerant carriers. More precisely, we compare recent available Monte Carlo results with our two step approach (TSA) calculations. The TSA…