Related papers: Correlation Functions of the Magnetization in Thin…
By making use of some symmetry properties of the relevant Hamiltonian, two fundamental relations between the ferromagnetic magnetization and a spin correlation function are derived for the $d (=1,2,3)$-dimensional Hubbard model at finite…
Magnetic relaxation and critical current density have been measured on a $MgB_2$ thin film in a wide region of temperature with the magnetic field up to 8 T. The irreversibility line has also been determined. It is found that the relaxation…
The precessional magnetization dynamics of GaMnAs thin films are characterized by broadband network analyzer ferromagnetic resonance (FMR) in a coplanar geometry at cryogenic temperatures. The FMR frequencies are characterized as function…
Direct magnetization measurements of thin gold films are presented. These measurements integrate the signal from the thin film under study and the magnetic contribution of the film's interface with the substrate. The diamagnetic…
Recent work on layered structures of superconductors (S) or normal metals (N) in contact with ferromagnetic insulators (FI) has shown how the properties of the previous can be strongly affected by the magnetic proximity effect due to the…
We present a scheme to express a bath correlation function (BCF) corresponding to a given spectral density (SD) as a sum of damped harmonic oscillations. Such a representation is needed, for example, in many open quantum system approaches.…
The magnetization reversal process in thin-film ferromagnetic elements with surface anisotropy of various shapes and sizes is investigated by means of numerical simulation. The dependence of the perpendicular and in-plane hysteresis loops…
The spin-boson model is studied by means of flow equations for Hamiltonians. Our truncation scheme includes all coupling terms which are linear in the bosonic operators. Starting with the canonical generator $\eta_c=[H_0,H]$ with $H_0$…
We study the low-temperature behavior of antiferromagnets in two spatial dimensions that are subjected to a magnetic field oriented perpendicular to the staggered magnetization order parameter. The evaluation of the partition function is…
In this paper, the moderately long-time behaviours of the correlation functions for two charged coupled harmonic oscillators connected to a common heat bath are analyzed in the presence of a magnetic field via the Quantum Langevin dynamics.…
The low temperature magnetization process of the ferromagnetic-antiferromagnetic Heisenberg chain is studied using the interacting boson approximation. In the low field regime and near the saturation field, the spin wave excitations are…
Two magnets in relative motion interact through their dipolar fields, making individual magnetic moments dynamically adapt to the changes in the energy landscape and bringing about collective magnetization dynamics. Some of the energy of…
Fluctuations in conjugate thermodynamic variables are studied using the cross-correlation function. A new procedure is given enabling the derivation of fluctuation formulas for a system in equilibrium. Specifically, the cross-correlation…
We present a method to map the saturation magnetization of soft ultrathin films with perpendicular anisotropy, and we illustrate it to assess the compositional dependence of the magnetization of CoFeB(1 nm)/MgO films. The method relies on…
We have investigated the ferrimagnetic domain structure in a Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film using magnetic force microscopy. We observe clear signs of phase separation, with magnetic islands embedded in a non-magnetic matrix. We…
Recent advances in experimental techniques have made it possible to manipulate and measure the magnetization dynamics on the femtosecond time scale which is the same order as the correlation time of the bath degrees of freedom. In the…
The magnetoimpedance effect is a versatile tool to investigate ferromagnetic materials, revealing aspects on the fundamental physics associated to magnetization dynamics, broadband magnetic properties, important issues for current and…
We report on the origin of fragmentation of ultracold atoms observed on a permanent magnetic film atom chip. A novel technique is used to characterize small spatial variations of the magnetic field near the film surface using radio…
The ferromagnetic resonance frequencies are obtained for a thin ferromagnetic film with surface anisotropy for the cases when the external magnetic field is applied perpendicularly or parallel to the film surface, and for various…
The anisotropic magnetoresistance (AMR) in thin permalloy strips was calculated at each steps during magnetization by the finite element method. The magnetization at equilibrium under different external fields was obtained by micromagnetic…