Faraday rotation spectra of bismuth-substituted ferrite garnet films with in-plane magnetization

Single crystalline films of bismuth-substituted ferrite garnets have been synthesized by the liquid phase epitaxy method where GGG substrates are dipped into the flux. The growth parameters are controlled to obtain films with in-plane magnetization and virtually no domain activity, which makes them excellently suited for magnetooptic imaging. The Faraday rotation spectra were measured across the visible range of wavelengths. To interprete the spectra we present a simple model based on the existence of two optical transitions of diamagnetic character, one tetrahedral and one octahedral. We find excellent agreement between the model and our experimental results for photon energies between 1.77 and 2.53 eV, corresponding to wavelengths between 700 and 490 nm. It is shown that the Faraday rotation changes significantly with the amount of substituted gallium and bismuth. Furthermore, the experimental results suggest that the magnetooptic response changes linearly with the bismuth substitution.Comment: 15 pages, 6 figures, published in Phys. Rev.

Optical and Magnetooptical Properties of Copper and Cobalt-Manganese Ferrite Thin Films

Optical absorption and Faraday rotation of copper and cobalt-manganese ferrite thin films, prepared by sputtering, were measured in the visible and near infrared spectral regions. Main magneto-optical features can be explained by the respective transitions of CU2+ and Co2+ ions tetrahedrally and octahedrally coordinated. Annealings at 450 and 665°C cause migration of these ions into tetrahedral positions and, consequently, increase corresponding peaks in the figure of merit. Therefore, these films range among the promissing materials for the magneto-optical recording

Tumor-infiltrating B cell immunoglobulin variable region gene usage in invasive ductal breast carcinoma

A major focus of tumor immunology is to reveal the potential role and capacity of immunocompetent cells found in different solid tumor tissues. The most abundant infiltrating cells (TIL), the T lymphocytes have been investigated in details concerning T-cell receptor usage and specificity. However, B cells have hardly been investigated in this respect, although high cellular B-cell infiltration has been correlated with improved patients' survival in some breast carcinomas. This led to our objectives to study variable region gene usage of the tumor-infiltrating B cells in different breast carcinoma types. By defining the immunoglobulin repertoire of the tumor-infiltrating B lymphocytes in the most common invasive ductal carcinoma (IDC) of the breast we compared it to the rare medullary breast carcinoma (MBC). After phenotyping infiltrating ductal carcinomas, B cells were obtained from tumor tissue by microdissection technique. Numerous rearranged TIL-B immunoglobulin heavy chain V genes (VH) were amplified, cloned, sequenced, and comparatively analyzed. Some characteristics were found for both breast carcinoma types. The immunoglobulins produced by TIL-B in ductal carcinoma are highly matured and oligoclonal. We conclude that Ig variable region gene usage reveals similar and distinguishable characteristics of TIL-B immunoglobulin repertoires, which are representative of the nature of the immune responses in invasive ductal and medullary breast carcinomas

Quasiclassical approach to quantum quench dynamics in the presence of an excited-state quantum phase transition

The dynamics of a quantum system following a sudden, highly nonadiabatic change of its control parameter (quantum quench) is studied with quasiclassical techniques. Recent works have shown, using exact quantum mechanical approach, that equilibration after quantum quench exhibits specific features in the presence of excited-state quantum phase transitions. In this paper, we demonstrate that these features can be understood from the classical evolution of the Wigner function in phase space

Kerr Rotation and XPS Spectra of Co/Pd Multilayers

The influence of the surface conditions of a series of the polycrystalline Co/Pd multilayers on the spectral dependence of the polar Kerr rotation, θk, was studied. Starting from low values, |θk| was found to increase towards short wavelengths, reaching 0.2 degree at the blue region. Using angular resolved photoelectron spectroscopy the oxidation states and the binding conditions of Co and Pd nearest surface layers were examined