Correlation between spin helicity and electric polarization vector in quantum-spin chain magnet LiCu2_2O2_2

Measurements of polarized neutron scattering were performed on a $S=1/2$ chain multiferroic LiCu$_2$O$_2$. In the ferroelectric ground state with the spontaneous polarization along the c-axis, the existence of transverse spiral spin component in the $bc$-plane was confirmed. When the direction of electric polarization is reversed, the vector spin chirality as defined by ${\bf C}_{ij} = {\bf S}_i \times {\bf S}_j$ ($i$ and $j$ being the neighboring spin sites) is observed to be reversed, indicating that the spin-current model or the inverse Dzyaloshinskii-Moriya mechanism is applicable even to this $e_{\mathrm{g}}$-electron quantum-spin system. Differential scattering intensity of polarized neutrons shows a large discrepancy from that expected for the classical-spin $bc$-cycloidal structure, implying the effect of large quantum fluctuation.Comment: 5 pages, 3 figure

Lamination of the cerebral cortex is disturbed in Gli3 mutant mice

AbstractThe layered organization of the cerebral cortex develops in an inside-out pattern, a process which is controlled by the secreted protein reelin. Here we report on cortical lamination in the Gli3 hypomorphic mouse mutant XtJ/Pdn which lacks the cortical hem, a major source of reelin+ Cajal Retzius cells in the cerebral cortex. Unlike other previously described mouse mutants with hem defects, cortical lamination is disturbed in XtJ/Pdn animals. Surprisingly, these layering defects occur in the presence of reelin+ cells which are probably derived from an expanded Dbx1+ progenitor pool in the mutant. However, while these reelin+ neurons and also Calretinin+ cells are initially evenly distributed over the cortical surface they form clusters later during development suggesting a novel role for Gli3 in maintaining the proper arrangement of these cells in the marginal zone. Moreover, the radial glial network is disturbed in the regions of these clusters. In addition, the differentiation of subplate cells is affected which serve as a framework for developing a properly laminated cortex

Nagoya University Photo-Science Nanofactory Project

Nagoya University has a project to construct a new synchrotron light facility, called Photo-Science Nanofactory, to develop a wide range research on basic science, industrial applications, life science and environmental engineering in collaboration with universities, research institutes and industries. The key equipment of the facility is a compact electron storage ring, “Nagoya University Small Synchrotron Radiation facility (NSSR),” which is able to supply hard x-rays. The plan of the specifications is as following. The energy of the stored electron beam is 1.2 GeV. The circumference is 62.4 m. Natural emittance is about 60 nmrad. The configuration of the storage ring is considered based on the Triple Bend Achromat with twelve bending magnets. Eight of them are normal conducting magnets. Four of them are 5T superconducting magnets (super-bends). The bending angle is 12 degrees and two or three hard x-ray beam lines can be constructed for each super-bend. The number of beam lines from normal conducting bending magnets is more than 16. In addition, we will install two undulators in straight sections. The electron beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection. A 50 MeV linac is used as an injector to the booster synchrotron. The top-up operation is also planned