Three-Dimensional Reconstruction of the Fermi Surface of LaB6
Three-Dimensional Reconstruction of the Fermi Surface of LaB6
复制标题
LaB6 费米面的三维重建
DOI：
10.4028/www.scientific.net/msf.363-365.582
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
N. Sato
中科院分区：
文献类型：
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作者：
M. Biasini;M. Monge;G. Kontrym‐Sznajd;M. Gemmi;N. Sato
测量了正电子湮没辐射（2D-ACAR）在LaB_6单晶上的三个投影的二维角关联。对2D-ACAR光谱进行货车Citter-Gerhard去卷积算法。从实验光谱中，我们通过三种不同的方法产生了3D k空间密度rho（k）：i）我们通过Cormack方法重建了3D电子-正电子动量密度rho（p）。然后通过将3D LCW变换应用于rho（p）来获得rho（k）。ii）采用改进的基于傅立叶变换的算法重复点i）的相同步骤。iii）通过用长椭圆体参数化费米表面体积直接获得3d k-空间占有率rho（k），长椭圆体的轴通过应用于两个高对称投影的2D LCW变换的最小二乘拟合来确定。沿立方布里渊区（BZ）的高对称方向的椭球体直径沿着为BZ尺寸的0.64（dir. X-M）和0.82（dir. Gamma-X）。作为BZ体积的分数，得到的费米体积为0.55。这些结果与de哈斯货车Alphen实验结果在1%以内一致。
The 2-dimensional angular correlations of the positron annihilation radiation (2D-ACAR) on a single crystal of LaB6 was measured for three projections. The 2D-ACAR spectra were subjected to the Van Citter-Gerhard deconvolution alghorithm. From the experimental spectra we produced the 3D k-space density rho(k) via three different methods: i) we reconstructed the 3D electron-positron momentum density rho(p) via the Cormack method. rho(k) was then obtained by applying the 3D LCW transformation to rho(p). ii) The same steps of point i) were repeated adopting a modified Fourier-transform-based algorithm. iii) The 3d k-space occupancy rho(k) was obtained directly by parameterising the Fermi surface volume with prolate ellipsoids whose axes were determined by a least-square fit to the 2D LCW transformations applied to two high symmetry projections. The ellipsoids diameters along high symmetry directions of the cubic Brillouin zone (BZ), as a fraction of the BZ size, were 0.64 (dir. X-M) and 0.82 (dir. Gamma-X). The resulting Fermi volume, as a fraction of the BZ volume, was 0.55. These results agree within 1% with those obtained via the de Haas van Alphen experiments.