Electronic Theory for the Nonlinear Magneto-Optical Response of Transition-Metals at Surfaces and Interfaces: Dependence of the Kerr-Rotation on Polarization and on the Magnetic Easy Axis

We analyze laser-induced ultrafast, spatially inhomogeneous magnetization dynamics of epitaxial Co/Cu(001) films in a 0.4-10 nm thickness range with time-resolved magnetization-induced second harmonic generation, which probes femtosecond spin dynamics at the vacuum/Co and Co/Cu interfaces. The interference of these two contributions makes the overall signal particularly sensitive to differences in the transient magnetization redistribution between the two interfaces, i.e. ult...

Magneto-optic Kerr effect can probe the process of magnetization reversal in ferromagnetic thin films and thus be used as an alternative to magnetometry. Kerr effect is wavelength-dependent and the Kerr rotation can reverse sign, vanishing at particular wavelengths. We investigate epitaxial heterostructures of ferromagnetic manganite, La$_{0.7}$Sr$_{0.3}$Mn$_{0.9}$Ru$_{0.1}$O$_3$, by polar Kerr effect and magnetometry. The manganite layers are separated by or interfaced with ...

Co /CoO/Co polycrystalline film was grown on Si (001) substrate and magnetic properties have been investigated using in-situ magneto-optic Kerr effect during growth of the sample. Magnetic anisotropy with easy axis perpendicular to the film surface has been observed in top Co layer, whereas bottom layer was found to be soft with in-plane magnetization without any influence of top layer. Ex-situ in-plane and out-of-plane diffraction measurements revealed that the growth of Co ...

We report on time- and angle-resolved transverse magneto-optical Kerr effect spectroscopy in the soft x-ray range that, by analysis via polarization-dependent magnetic scattering simulations, allows us to determine the spatio-temporal and element-specific evolution of femtosecond laser-induced spin dynamics in nanostructured magnetic materials. In a ferrimagnetic GdFe thin film system, we correlate a reshaping spectrum of the magneto-optical Kerr signal to depth-dependent mag...

In this paper we develop the excitonic theory of Kerr rotation angle in a two-dimensional (2D) transition metal dichalcogenide at zero magnetic field. The finite Kerr angle is induced by the interplay between spin-orbit splitting and proximity exchange coupling due to the presence of a ferromagnet. We compare the excitonic effect with the single particle theory approach. We show that the excitonic properties of the 2D material lead to a dramatic change in the frequency depend...

We report a joint theoretical and experimental study focused on understanding the optical and magneto-optical properties of Co-based full-Heusler compounds. We show that magneto-optical spectra calculated within ab-initio density functional theory are able to uniquely identify the features of the experimental spectra in terms of spin resolved electronic transitions. As expected for 3d-based magnets, we find that the largest Kerr rotation for these alloys is of the order of 0....

Single-layer transition-metal dichalcogenides provide an unique intrinsic entanglement between the spin/valley/orbital degrees of freedom and the polarization of scattered photons. This scenario gives rise to the well-assessed optical dichroism observed by using both steady and time-resolved probes. In this paper we provide a compact analytical modelling of the onset of a finite Faraday/Kerr optical rotation upon shining with a circularly polarized light. We identify differen...

We present a method for a precise determination of magnetic anisotropy and anisotropy of quadratic magneto-optical response of thin films of ferromagnetic and ferrimagnetic materials. The method is based on measurements of a magneto-optical response for light close to the normal incidence on the sample with a fixed position. The measurement is performed for a set of orientations of an external magnetic field and a series of incident light linear polarizations beyond the stand...

Antiferromagnetic metals attract tremendous interest for memory applications due to their expected fast response dynamics in the terahertz frequency regime. Reading from and writing information into these materials is not easily achievable using magnetic fields, due to weak high-order magneto-optical signals and robustness of the magnetic structure against external magnetic fields. Polarized electromagnetic radiation is a promising alternative for probing their response, howe...

By means of spin-polarized low-energy electron microscopy (SPLEEM) we show that the magnetic easy-axis of one to three atomic-layer thick cobalt films on ruthenium crystals changes its orientation twice during deposition: one-monolayer and three-monolayer thick films are magnetized in-plane, while two-monolayer films are magnetized out-of-plane, with a Curie temperature well above room temperature. Fully-relativistic calculations based on the Screened Korringa-Kohn-Rostoker (...