Microscopic Origin of Magnetoelectric Coupling in Noncollinear Multiferroics Jiangping Hu
... number of free parameters, the mechanism can estimate the value of ferroelectricity. The free parameters can be independently measured using various experimental techniques. For example, the energy gap in the multiferroics and the spin-orbit coupling strength can be measured in optical absorption sp ...
... number of free parameters, the mechanism can estimate the value of ferroelectricity. The free parameters can be independently measured using various experimental techniques. For example, the energy gap in the multiferroics and the spin-orbit coupling strength can be measured in optical absorption sp ...
Electronic g Factor of Hydrogenlike Oxygen 16O7+
... The situation is more complex when dealing with particles bound to a nucleus of charge Z mainly because the standard method of calculation by use of a perturbation expansion is not applicable anymore: while for a free particle the expansion parameter is the fine structure constant and is thus smal ...
... The situation is more complex when dealing with particles bound to a nucleus of charge Z mainly because the standard method of calculation by use of a perturbation expansion is not applicable anymore: while for a free particle the expansion parameter is the fine structure constant and is thus smal ...
Semiconductor-based spintronics devices
... – No working devices has been reported… Spin-FET ...
... – No working devices has been reported… Spin-FET ...
Magnetism and Matter
... Diamagnetism is a property of all materials and opposes applied magnetic fields, but is very weak. Paramagnetism, when present, is stronger than diamagnetism and produces magnetization in the direction of the applied field, and proportional to the applied field. The magnetization of a material is ex ...
... Diamagnetism is a property of all materials and opposes applied magnetic fields, but is very weak. Paramagnetism, when present, is stronger than diamagnetism and produces magnetization in the direction of the applied field, and proportional to the applied field. The magnetization of a material is ex ...
Langevin spin dynamics based on ab initio calculations: numerical
... Hamiltonian describing a linear chain of atoms with ferromagnetic nearest-neighbour Heisenberg coupling. The model was chosen since it has an analytic solution [22, 23], therefore the numerical results can be compared to exact values. Another reason for studying this model is that linear chains of a ...
... Hamiltonian describing a linear chain of atoms with ferromagnetic nearest-neighbour Heisenberg coupling. The model was chosen since it has an analytic solution [22, 23], therefore the numerical results can be compared to exact values. Another reason for studying this model is that linear chains of a ...
Geometrical frustration
In condensed matter physics, the term geometrical frustration (or in short: frustration) refers to a phenomenon, where atoms tend to stick to non-trivial positions or where, on a regular crystal lattice, conflicting inter-atomic forces (each one favoring rather simple, but different structures) lead to quite complex structures. As a consequence of the frustration in the geometry or in the forces, a plenitude of distinct ground states may result at zero temperature, and usual thermal ordering may be suppressed at higher temperatures. Much studied examples are amorphous materials, glasses, or dilute magnets.The term frustration, in the context of magnetic systems, has been introduced by Gerard Toulouse (1977). Indeed, frustrated magnetic systems had been studied even before. Early work includes a study of the Ising model on a triangular lattice with nearest-neighbor spins coupled antiferromagnetically, by G. H. Wannier, published in 1950. Related features occur in magnets with competing interactions, where both ferro- as well as antiferromagnetic couplings between pairs of spins or magnetic moments are present, with the type of interaction depending on the separation distance of the spins. In that case commensurability, such as helical spin arrangements may result, as had been discussed originally, especially, by A. Yoshimori, T. A. Kaplan, R. J. Elliott, and others, starting in 1959, to describe experimental findings on rare-earth metals. A renewed interest in such spin systems with frustrated or competing interactions arose about two decades later, beginning in the 70s of the 20th century, in the context of spin glasses and spatially modulated magnetic superstructures. In spin glasses, frustration is augmented by stochastic disorder in the interactions, as may occur, experimentally, in non-stoichiometric magnetic alloys. Carefully analyzed spin models with frustration include the Sherrington-Kirkpatrick model, describing spin glasses, and the ANNNI model, describing commensurability magnetic superstructures.