Finite-size effects in layered magnetic systems

Boundary and finite-size effects in small magnetic systems

We study the effect of free boundaries in finite magnetic systems of cubic shape on the field and temperature dependence of the magnetisation within the isotropic model of D-component spin vectors in the limit D → ∞. This model is described by a closed system of equations and captures the Goldstone-mode effects such as global rotation of the magnetic moment and spin-wave fluctuations. We have o...

Finite size effects in patterned magnetic permalloy films

Electron beam lithography has been used to prepare 250-Å-thick square-shaped permalloy dots whose width and separation are in the range between 1 and 4 mm. The static and dynamic magnetic properties of these structures have been investigated by complementary techniques such as magneto-optic Kerr effect ~MOKE!, magnetic force microscopy ~MFM!, and Brillouin light scattering ~BLS!. Longitudinal M...

Finite Two Layered Queueing Systems

Coulomb finite-size effects in quasi-two-dimensional systems

The model periodic Coulomb interaction (Williamson et al 1997 Phys. Rev. B 55 R4851) is a replacement for the Ewald sum, developed to reduce finitesize errors in the simulation of extended 3D systems. We investigate the generalization of this technique to quasi-2D systems; we show through testing in quantum Monte Carlo simulations that while the new interaction reduces the calculation time dram...

Gilbert damping in magnetic layered systems

The Gilbert damping constant present in the phenomenological Landau-Lifshitz-Gilbert equation describing the dynamics of magnetization is calculated for ferromagnetic metallic films as well as Co/nonmagnet (NM) bilayers. The calculations are done within a realistic nine-orbital tight-binding model including spin-orbit coupling. The convergence of the damping constant expressed as a sum over the...