Inertia effects in magnetization dynamics are theoretically shown to result a different type of spin waves, i.e. nutation surface which propagate at terahertz frequencies in-plane magnetized ferromagnetic thin films. Considering the magnetostatic limit, neglecting exchange coupling, we calculate dispersion relation and group velocity, find be slower than velocity conventional (precession) waves...

The dispersion relations of energy bands in solids are characterized by their density of states, but a given density of states may originate from various band structures. We show how a spherically symmetric dispersion can be constructed for any one-band density of states. This method is applied to one-, twoand three-dimensional systems. It also serves to establish that any one-band spectrum wit...

A parameter optimized approach for reducing the numerical dispersion of the 3-D hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) is presented in this letter. By adding a parameter into the HIE-FDTD formulas, the error of the numerical phase velocity can be controlled, causing the numerical dispersion to decrease significantly. The numerical stability and dispersion relation are...

A dispersion relation technique is used to obtain the retarded dispersion energy of two neutral atoms in nondegenerate ground states. To that end multipole expansions are derived for the electromagnetic form factors occurring in the vertex function that characterizes the interaction of a neutral atom with a pair of photons on the mass shell. The long-range asymptotic expression for the dispersi...