相关论文: Modeling Molecular Magnets with Large Exchange and…
Single molecule magnets (SMMs) with single-ion anisotropies $\mathbf d$, comparable to exchange interactions J, between spins have recently been synthesized. In this paper, we provide theoretical insights into the magnetism of such systems.…
We present a theoretical approach to calculate the molecular magnetic anisotropy parameters, $D_M$ and $E_M$ for single molecule magnets in any eigenstate of the exchange Hamiltonian, treating the anisotropy Hamiltonian as a perturbation.…
This chapter takes a microscopic view of quantum tunneling of magnetization (QTM) in single-molecule magnets (SMMs), focusing on the interplay between exchange and anisotropy. Careful consideration is given to the relationship between…
We study single-ion and exchange anisotropy effects in equal-spin $s_1$ tetramer single molecule magnets exhibiting $T_d$, $D_{4h}$, $D_{2d}$, $C_{4h}$, $C_{4v}$, or $S_4$ ionic point group symmetry. We first write the group-invariant…
To understand the effect of molecular environment on the electronic and magnetic properties of the single-molecule magnet (SMM) Mn$_{12}$, we explore two possible means for adding extra electrons to molecule. We explore both substitution of…
We present a review of recent advances in the study of many-body effects in magnetic nanoparticles. Considering classical spins on a lattice coupled by the exchange interaction in the presence of the bulk and surface anisotropy, we…
The spin-orbit interaction in semiconductors is shown to result in an anisotropic contribution into the exchange Hamiltonian of a pair of localized conduction-band electrons. The anisotropic exchange interaction exists in semiconductor…
The properties of quantum systems interacting with their environment, commonly called open quantum systems, can be strongly affected by this interaction. While this can lead to unwanted consequences, such as causing decoherence in qubits…
Magnetic materials are usually characterized by anisotropy energy barriers which dictate the time scale of the magnetization decay and consequently the magnetic stability of the sample. Here we present a unified description, which includes…
We investigate the far-from-equilibrium nature of magnetic anisotropy and exchange interactions between molecular magnets embedded in a tunnel junction. By mapping to an effective spin model, these magnetic interactions can be divided into…
Motivated by the recent suggestion of anisotropic effective exchange interactions between Mn spins in Ga$_{1-x}$Mn$_x$As (arising as a result of spin-orbit coupling), we study their effects in diluted Heisenberg spin systems. We perform…
Mapping the magnetic exchange interactions from model Hamiltonian to density functional theory is a crucial step in multi-scale modeling calculations. Considering the usual magnetic force theorem but with arbitrary rotational angles of the…
Magnetic properties of a tetrahedral "Ni_4" molecule are discussed in terms of the Heisenberg model, with magnetic anisotropy terms included, and on the basis of first-principle calculations within the density functional theory. It is shown…
The effect of dipolar interaction and local uniaxial anisotropy on the magnetic response of small spin clusters where spins are located on the vertices of icosahedron, cuboctahedron, tetrahedron and square geometry have been investigated.…
We study the modification of low temperature properties of quantum magnets such as magnetization, heat capacity, energy spectrum, and densities of condensed and noncondensed quasiparticles (triplons) due to anisotropies in the framework of…
We investigate the effect of coupling (intensity and nature), applied field, and anisotropy on the spin dynamics of a multi-layer system composed of a hard magnetic slab coupled to a soft magnetic slab through a nonmagnetic spacer. The soft…
The effects of spin-orbit coupling on the two-electron spectra in lateral coupled quantum dots are investigated analytically and numerically. It is demonstrated that in the absence of magnetic field the exchange interaction is practically…
We present a new mechanism for a spin blockade effect associated with a change in the type of magnetic anisotropy over oxidation state in a single molecule transistor, by taking an example of an individual Eu$_{2}$(C$_{8}$H$_{8}$)$_{3}$…
The low energy excitation spectrum of a two-dimensional ferromagnetic material is dominated by single-magnon excitations that show a gapless parabolic dispersion relation with the spin wave vector. This occurs as long as magnetic anisotropy…
An attractive feature of magnetic adatoms and molecules for nanoscale applications is their superparamagnetism, the preferred alignment of their spin along an easy axis preventing undesired spin reversal. The underlying magnetic anisotropy…