301 research outputs found

    Anisotropic spin-density distribution and magnetic anisotropy of strained La1x_{1-x}Srx_xMnO3_3 thin films: Angle-dependent x-ray magnetic circular dichroism

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    Magnetic anisotropies of ferromagnetic thin films are induced by epitaxial strain from the substrate via strain-induced anisotropy in the orbital magnetic moment and that in the spatial distribution of spin-polarized electrons. However, the preferential orbital occupation in ferromagnetic metallic La1x_{1-x}Srx_xMnO3_3 (LSMO) thin films studied by x-ray linear dichroism (XLD) has always been found out-of-plane for both tensile and compressive epitaxial strain and hence irrespective of the magnetic anisotropy. In order to resolve this mystery, we directly probed the preferential orbital occupation of spin-polarized electrons in LSMO thin films under strain by angle-dependent x-ray magnetic circular dichroism (XMCD). Anisotropy of the spin-density distribution was found to be in-plane for the tensile strain and out-of-plane for the compressive strain, consistent with the observed magnetic anisotropy. The ubiquitous out-of-plane preferential orbital occupation seen by XLD is attributed to the occupation of both spin-up and spin-down out-of-plane orbitals in the surface magnetic dead layer.Comment: 20 pages, 4 figure

    Photodisintegration of 80Se^{80}Se as a probe of neutron capture for the s-process branch-point nucleus 79Se^{79}Se

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    Photoneutron cross sections were measured for 80Se near the neutron separation energy with the laser Compton scattering γ rays. The stellar neutron capture rate for 79Se was evaluated by using the photodisintegration data as constraints on the E1 γ strength function within the framework of the Hauser-Feshbach statistical model. The result is compared with the model calculation of Bao and Käppeler. © Copyright owned by the author(s).SCOPUS: cp.pinfo:eu-repo/semantics/publishe

    Non-holomorphic terms in N=2 SUSY Wilsonian actions and RG equation

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    In this paper we first investigate the Ansatz of one of the present authors for K(\Psi,\bar\Psi), the adimensional modular invariant non-holomorphic correction to the Wilsonian effective Lagrangian of an N=2 globally supersymmetric gauge theory. The renormalisation group beta-function of the theory crucially allows us to express K(\Psi,\bar\Psi) in a form that easily generalises to the case in which the theory is coupled to N_F hypermultiplets in the fundamental representation of the gauge group. This function satisfies an equation which should be viewed as a fully non-perturbative ``non-chiral superconformal Ward identity". We also determine its renormalisation group equation. Furthermore, as a first step towards checking the validity of this Ansatz, we compute the contribution to K(\Psi,\bar\Psi) from instantons of winding number k=1 and k=2. As a by-product of our analysis we check a non-renormalisation theorem for N_F=4.Comment: 39 pages, LaTex file, no figure
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