Computer experiments on the information depth and the figure of merit in magnetooptics

Abstract

A numerical simulation procedure is used to answer some fundamental questions about magnetooptical phenomena. By investigating hypothetical thin buried layers of magnetic material in a non‐magnetic environment of otherwise identical optical properties a suggestive law is derived for the information depth profile of Kerr effect measurements. Differences in phase between contributions from different depth often limit the range of the Kerr effect to a higher degree than absorption. In oxides the profile has usually an oscillating character, but conditions are derived under which these oscillations can be suppressed. The differing phase of sub‐surface contributions connects these considerations with Kamberský's interpretation of the recently discovered magnetooptical gradient effect. Finally, the theoretical and practical possibilities are explored of enhancing the Kerr effect in ultra‐thin films in which all the light is forced to react in a thin layer rather than in the depth of a thick material. In this connection a far‐reaching generalization of Lissberger's limit for the Kerr amplitude in thin film mirror‐based systems is discovered.

Separation of ultrafast spin currents and spin-flip scattering in Co/Cu(001) driven by femtosecond laser excitation employing the complex magneto-optical Kerr effect

“…Following Traeger et al [40], ζ(z) was calculated by setting m = 0 with the exception of a part z, z +dz where m = 1, and determining the complex Kerr angle of this part Φ dz = θ dz + iǫ dz for this system. To take pumpinduced changes into account we normalized Φ dz to the equilibrium values and obtain…”

Speed and efficiency of femtosecond spin current injection into a nonmagnetic material

“…For the interpretation of the collected C-MOKE data, it is necessary to distinguish between element dependence [25] and depth dependence [26,27] of the C-MOKE method. In our case, where we want to make use of the element dependence to gain layer specificity, we fabricated a sufficiently thin Ni layer, where the depth-dependent dynamics in Ni can be neglected [see Supplemental Material (SM) [28]].…”

Selective sensitivity of ellipsometry to magnetic nanostructures

“…2.1. Figure 3 shows a model of magneto-optical ultrathin (1 Å thick) Co film buried in non-magneto-optic Co bulk in the deepth t. The similar modeling was originally proposed by Traeger [6] and Hubert [7]. Fig.…”

“…Moreover, the magneto-optic Kerr effects enable us to separate magnetic contributions from different depth [6][7][8][9][10] and from different materials [11,12] in multilayer systems and self-organized nanostructures [13].…”