Showing papers by "Herbert B. Callen published in 1958"

Orbit-Orbit Interactions in Atomic Spectra

Abstract: Empirical spectroscopic evidence suggests the existence of an orbit-orbit interaction between electrons, of the form $\ensuremath{\alpha}{\mathrm{l}}_{1}\ifmmode\cdot\else\textperiodcentered\fi{}{\mathrm{l}}_{2}$, and of a magnitude comparable to the spin-orbit interaction. The direct magnetic interaction is of this form, but previous calculations have yielded too small a magnitude. We suggest that the magnetic interaction is uniquely sensitive to the correlation of the interacting electrons, and that introduction of a reasonable correlation in the wave function may well increase the magnetic interaction to the magnitudes required by the empirical data.

Ferromagnetic Dynamical Response

Abstract: A dynamical equation, describing the response of the magnetization to an applied field, is proposed. The analysis is based on a spin‐wave picture. The dynamical equation contains three parameters, defined in terms of particular magnon‐magnon and magnon‐phonon transition probabilities. A more detailed theory for one of these parameters is developed. The resultant size and shape dependence of the magnetic loss is suggestive of experimental observations.