相关论文: Local force method for the ab initio tight-binding…

We explore spin dependent transport through a magnetic quantum wire which is attached to two non-magnetic metallic electrodes. We adopt a simple tight-binding Hamiltonian to describe the model where the quantum wire is attached to two…

Atomic-scale computational modeling of technologically relevant permanent magnetic materials faces two key challenges. First, a material's magnetic properties depend sensitively on temperature, so the calculations must account for thermally…

We present a second-order Green's-function theory of the one- and two-dimensional S=1/2 ferromagnet in a magnetic field based on a decoupling of three-spin operator products, where vertex parameters are introduced and determined by exact…

Exchange interactions up to fourth nearest neighbor are shown within a classical local-moment Heisenberg approach to be important to model inelastic neutron scattering data on the fcc kagome antiferromagnet IrMn$_3$. Spin wave frequencies…

We present a first-principles theory of the variation of magnetic anisotropy, K, with temperature, T, in metallic ferromagnets. It is based on relativistic electronic structure theory and calculation of magnetic torque. Thermally induced…

We study the ferromagnetic Kondo model with classical corespins via unbiased Monte-Carlo simulations and derive a simplified model for the treatment of the corespins at any temperature. Our simplified model captures the main aspects of the…

The coupled cluster method (CCM) is a powerful and widely applied technique of modern-day quantum many-body theory. It has been used with great success in order to understand the properties of quantum magnets at zero temperature. This is…

We show how temperature-induced disorder can be combined in a direct way with first-principles scattering theory to study diffusive transport in real materials. Excellent (good) agreement with experiment is found for the resistivity of Cu,…

We investigate the effect of a magnetic field on the Kitaev model using the equation of motion approach for the spin Green's function, considering both the case of suppressed magnetization ($m = 0$) and finite magnetization ($m \neq 0$).…

We present a general formula for the tight-binding representation of momentum matrix elements needed for calculating the conductivity based on the Kubo-Greenwood formula using atomic orbitals, which are in general not orthogonal to other…

Using quantum Heisenberg model calculations with Green's function technique generalized for arbitrary spins, we found that for a system of small spins the quantum spin effects significantly contribute to the magnetic short-range order and…

We report on a study of the temperature and Zeeman-coupling-strength dependence of the one-particle Green's function of a two-dimensional (2D) electron gas at Landau level filling factor $\nu =1$ where the ground state is a strong…

In the spirit of multi-scale modelling magnetization dynamics at elevated temperature is often simulated in terms of a spin model where the model parameters are derived from first principles. While these parameters are mostly assumed…

The magnetization of body-centered cubic iron at low temperatures is calculated with the steepest-entropy-ascent quantum thermodynamics (SEAQT) framework. This framework assumes that a thermodynamic property in an isolated system traces the…

Temperature-dependent dynamical spin correlations, which can be readily accessed via a variety of experimental techniques, hold the potential of offering a unique fingerprint of quantum spin liquids and other intriguing dynamical states. In…

In this work we present the results of an experiment to locally resolve the spin Seebeck effect in a high-quality Pt/YIG sample. We achieve this by employing a locally heated scanning thermal probe to generate a highly local non-equilibrium…

We present a theory based on Green's function formalism to study magnetism in disordered Heisenberg systems with long range exchange integrals. Disordered Green's function are decoupled within Tyablicov scheme and solved with a CPA method.…

There has been considerable recent progress in identifying candidate materials for the transverse-field Ising chain (TFIC), a paradigmatic model for quantum criticality. Here, we study the local spin dynamical structure factor of different…

We consider the mapping of tight-binding electronic structure theory to a local spin Hamiltonian, based on the adiabatic approximation for spin degrees of freedom in itinerant-electron systems. Local spin Hamiltonians are introduced in…

We calculate the molecular-spin ($S$), temperature ($T$), and field ($H$) dependence of $1/T_1$ for a local magnetic probe coupled to an isotropic high spin molecule, based on spin-phonon interaction. We compare the calculation to recent…