Related papers: Heisenberg exchange parameters of molecular magnet…
The method for calculating the isotropic exchange interactions in the paramagnetic phase is proposed. It is based on the mapping of the high-temperature expansion of the spin-spin correlation function calculated for the Heisenberg model…
We consider the extended Hubbard model and introduce a corresponding Heisenberg-like problem written in terms of spin operators. The derived formalism is reminiscent of Anderson's idea of the effective exchange interaction and takes into…
We report a novel practical method to determine exchange parameters by using experimental susceptibility data in a relatively narrow temperature region and a low order high-temperature-expansion equation. This method is applied to a square…
We present a method to compute the magnetic susceptibility of spin systems at all temperatures in one and two dimensions. It relies on an approximation of the entropy versus energy (microcanonical potential function) on the whole range of…
We show that the high-temperature expansion of the free energy and arbitrary imaginary-time-ordered connected correlation functions of quantum spin systems can be recursively obtained from the exact renormalization group flow equation for…
Magnetic susceptibility measured for CaV$_4$O$_9$ is analyzed by a method with high temperature expansion. The analysis is consistent with the $g$-value which is close to 2 and is observed by an ESR experiment. Four exchange parameters in a…
We develop a low-temperature expansion for the finite temperature dynamical structure factor of the spin half Heisenberg chain with alternating nearest neighbour exchange in the limit of strong alternation of the exchange constants. We…
We compute the magnetic susceptibility and specific heat of the spin-1/2 Heisenberg model on the kagome lattice with high-temperature expansions and exact diagonalizations. We compare the results with the experimental data on ZnCu3(OH)6Cl2…
Exchange coupling parameters $J_{ij}$ in the Heisenberg model are crucial for describing magnetic behavior at the atomic level. In magnetic materials, spin fluctuations can be accompanied by a self-consistent electronic response --…
We present a high-temperature series expansion code for spin-1/2 Heisenberg models on arbitrary lattices. As an example we demonstrate how to use the application for an anisotropic triangular lattice with two independent couplings J1 and J2…
A well-known connection between the magnetic susceptibility and the effective exchange parameter is analyzed. It is shown that all current computational schemes use a long-wave approximation which is suitable only for localized moments…
Inelastic neutron scattering (INS) provides direct insights into microscopic magnetic interactions in crystalline materials, making it a valuable experimental technique in condensed matter physics and materials science. These interactions…
In an effort to understand the low temperature behavior of recently synthesized molecular magnets we present numerical evidence for the existence of a rotational band in systems of quantum spins interacting with nearest-neighbor…
We present a method of extracting the exchange parameters of the classical Heisenberg model from first-principles calculations of spin-spiral total energies based on density functional theory. The exchange parameters of the transition-metal…
The expression of the thermal fluctuation parameter in the stochastic Landau-Lifshitz-Gilbert equation has been derived from a fundamental quantum theory of spins and phonons, in which the exchange interaction between nearest atoms has been…
We study thermodynamic properties of the one-dimensional Heisenberg ferrimagnet with antiferromagnetically exchange-coupled two kinds of spins 1 and 1/2. The specific heat and the magnetic susceptibility are calculated employing a modified…
Using exact diagonalization techniques we study the dynamical response of the anisotropic disordered Heisenberg model for systems of S=1/2 spins with infinite range random exchange interactions at temperature T=0. The model can be…
Theoretical prediction of the 2nd-order magnetic transition temperature (TM) used to be arduous. Here, we develop a first principle-based, fully automatic structure-to-TM method for two-dimensional (2D) magnets whose effective Hamiltonians…
We study ballistic thermal transport in Heisenberg spin chain with nearest-neighbor ferromagnetic interactions at low temperatures. Explicit expressions for transmission coefficients are derived for thermal transport in a periodic spin…
A model relevant for the study of certain molecular magnets is the ring of N=4 classical spins with equal near-neighbor isotropic Heisenberg exchange interactions. Assuming classical Heisenberg spin dynamics, we solve explicitly for the…