Search

The mechanism of the high temperature hole-doped superconductivity was investigated by Raman scattering. The Raman selection rule is unique, so that anisotropic magnetic excitations in a fluctuating spin-charge stripe can be detected as if it is static. We use different Raman selection rules for two kinds of magnetic Raman scattering processes, two-magnon scattering and high-energy electronic scattering. In order to confirm the difference, the Raman spectra of striped La2-xSrxCuO4 (LSCO) and non-striped Nd2-xCexCuO4 (NCCO) were compared. The main results in LSCO are (1) magnetic excitations are presented by individual energy dispersions for the k\parallel stripe and the k\perp stripe, (2) the charge transfer is allowed only in the direction perpendicular to the stripe. The direction is the same as the Burgers vector of an edge dislocation. Hence we assume that a charge moves together with the edge dislocation of the charge stripe. The superconducting coherence length is close to the inter-charge stripe distance at x < 0.2. Therefore we propose a model that superconducting pairs are formed in the edge dislocations. The binding energy is related to the stripe formation energy., Comment: 5 pages, 3 figures, International Conference on Superstripes 2012: Phase Separation and Superstripes in High Temperature Superconductors and Related Materials, 11-17 July, 2012, Erice-Sicily, Italy

Two magnon excitations and the nodal spin density wave (SDW) gap were observed in BaFe2As2 by Raman scattering. Below the SDW transition temperature (TSDW) nodal SDW gap opens together with new excitations in reconstructed electronic states. The two-magnon peak remains above TSDW and moreover the energy increases a little. The change from the long-range ordered state to the short-range correlated state is compared to the cuprate superconductors., Comment: 5 pages, 3 figures

The Hinode satellite (formerly Solar-B) of the Japan Aerospace Exploration Agency's Institute of Space and Astronautical Science (ISAS/JAXA) was successfully launched in September 2006. As the successor to the Yohkoh mission, it aims to understand how magnetic energy is transferred from the photosphere to the upper atmospheres and resulting in explosive energy releases. Hinode is an observatory style mission, with all the instruments being designed and built to work together to address the science aims. There are three instruments onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer (EIS), and the X-ray Telescope (XRT). This paper overviews the mission, including the satellite, the scientific payload and operations. It will conclude with discussions on how the international science community can participate in the analysis of the mission data.