Ceeh Hubert, Weber Josef Andreas, Böni Peter, Leitner Michael, Benea Diana, Chioncel Liviu, Ebert Hubert, Minár Jan, Vollhardt Dieter, Hugenschmidt Christoph
Technische Universität München, Lehrstuhl E21, James-Franck Straße, 85748 Garching, Germany.
Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, 85748 Garching, Germany.
Sci Rep. 2016 Feb 16;6:20898. doi: 10.1038/srep20898.
We employ a positron annihilation technique, the spin-polarized two-dimensional angular correlation of annihilation radiation (2D-ACAR), to measure the spin-difference spectra of ferromagnetic nickel. The experimental data are compared with the theoretical results obtained within a combination of the local spin density approximation (LSDA) and the many-body dynamical mean-field theory (DMFT). We find that the self-energy defining the electronic correlations in Ni leads to anisotropic contributions to the momentum distribution. By direct comparison of the theoretical and experimental results we determine the strength of the local electronic interaction U in ferromagnetic Ni as 2.0 ± 0.1 eV.
我们采用正电子湮灭技术，即湮灭辐射的自旋极化二维角关联（2D - ACAR），来测量铁磁镍的自旋差谱。将实验数据与在局域自旋密度近似（LSDA）和多体动态平均场理论（DMFT）相结合的框架下获得的理论结果进行比较。我们发现，定义镍中电子关联的自能对动量分布有各向异性贡献。通过理论与实验结果的直接比较，我们确定铁磁镍中局域电子相互作用U的强度为2.0 ± 0.1电子伏特。
