Ab initiomagneto-optical Kerr spectra for solid systems with reduction dimensions

Abstract

The complex optical conductivity tensor for layered systems is calculated on the basis of the Luttinger formula within the spin-polarized relativistic screened Korringa-Kohn-Rostoker method by means of a contour integration technique. Ab initio Kerr spectra are then obtained for arbitrary geometry and incidence via a 2 Â 2 matrix technique which includes all multiple reflections between layers and optical interferences in the layers. Applied to fcc Co/Pt layered systems it is shown that the Kerr spectra are highly sensitive to the surface orientation, its dependence on the Co slab and cap Pt thickness closely reflects, e.g. the ABCABC . . . stacking of the fcc (111) texture, and even for a moderate number of Co/Pt 3 bilayers a satisfactory good agreement with corresponding measurements is achieved.

Ab Initio Optical Properties of Tribological/Engineering Surfaces

“…The ''plain'' 2 9 2 matrix technique has been previously developed and applied with success to determine Kerr rotation angles by one of the authors [3], within either a polar [4], longitudinal [5], or arbitrary geometry [6] at oblique incidence and in the case of several magnetic layered systems [7,8]. This technique has been shown to correctly describe all multiple reflections and optical interferences within a surfaced system and to exactly reproduce the well-known Fresnel relations in particular when one deals with semi-infinite bulk-like systems [9].…”

“…The main advantage of the Luttinger formula (6) is that it simultaneously provides both absorptive and dispersive parts of the optical conductivity tensorrðxÞ on the same footing without using the well-known Kramers-Kronig relations [3]. A positive infinitesimal d [ 0 is introduced in Eqs.…”

“…However, in accordance with the only constraint d = 2d 2 applied to the selection of contour, if T is varied, the life-time broadening d also changes. A careful analysis of the T-dependence of the optical conductivity tensor has shown a negligible effect of the electronic temperature on the layer-resolved permittivities [3], therefore T was fixed to 300 K, leading to a broadening of the bands d = 4N 2 d T of 0.048 Ryd (0.650 eV).…”

“…A positive infinitesimal d [ 0 is introduced in Eqs. 6 and 7 to describe the interaction of the system with its surroundings [17], e.g., by switching on all fields at a moment t = -?, and also to account for all scattering processes at a temperature T = 0, which are not necessarily covered by a standard bandstructure calculation [3].…”

“…2, the basic concepts of the proposed two-scale framework are briefly presented and in Sect. 3, some details related to the numerical implementation are outlined. Results obtained for a semi-infinite bcc Fe/Fe(100) layered system are discussed in Sect.…”