Edmonds K W, van der Laan G, Freeman A A, Farley N R S, Johal T K, Campion R P, Foxon C T, Gallagher B L, Arenholz E
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2006 Mar 24;96(11):117207. doi: 10.1103/PhysRevLett.96.117207. Epub 2006 Mar 22.
Remarkably anisotropic Mn L2,3 x-ray magnetic circular dichroism spectra from the ferromagnetic semiconductor (Ga,Mn)As are reported. States with cubic and uniaxial symmetry are distinguished by careful analysis of the angle dependence of the spectra. The multiplet structures with cubic symmetry are qualitatively reproduced by calculations for an atomiclike d5 configuration in tetrahedral environment, and show zero anisotropy in the orbital and spin moments within the experimental uncertainty. However, hybridization with the host valence bands is reflected by the presence of a preedge feature with a uniaxial anisotropy and a marked dependence on the hole density.
报道了来自铁磁半导体(Ga,Mn)As的显著各向异性的Mn L2,3 x射线磁圆二色光谱。通过仔细分析光谱的角度依赖性,区分了具有立方和单轴对称性的状态。对于四面体环境中类原子d5构型的计算定性地再现了具有立方对称性的多重态结构,并且在实验不确定性范围内,轨道和自旋矩显示出零各向异性。然而,与主体价带的杂化通过具有单轴各向异性且对空穴密度有显著依赖性的前缘特征的存在而得以体现。