High-temperature cuprate superconductors studied by x-ray Compton scattering and positron annihilation spectroscopies
Bernardo Barbiellini
备注：
Invited talk presented at the 16th International Conference on Positron Annihilation (ICPA-16) held at the University of Bristol, United Kingdom during the period of 19-24 August, 2012
The bulk Fermi surface in an overdoped ($x = 0.3$) single crystal of La$_{2-x}$Sr$_{x}$CuO$_{4}$ has been observed by using x-ray Compton scattering. This momentum density technique also provides a powerful tool for directly seeing what the dopant Sr atoms are doing to the electronic structure of La$_2$CuO$_{4}$. Because of wave function effects, positron annihilation spectroscopy does not yield a strong signature of the Fermi surface in extended momentum space, but it can be used to explore the role of oxygen defects in the reservoir layers for promoting high temperature superconductivity.
Bulk Fermi surface and momentum density in heavily doped La$_{2-x}$Sr$_x$CuO$_4$ using high resolution Compton scattering and positron annihilation spectroscopies
本文用康普顿散射法观察了La $_{2-x}$ Sr $_x$ CuO $_4$的过掺杂（$x$ =0.3）单晶体费米面（FS）。根据测量的康普顿剖面进行的二维（2D）动量密度重建在沿[100]的第三布里渊区产生了清晰的FS特征。密度泛函理论（DFT）计算与动量密度实验之间的定量一致表明，费米液体物理恢复在过掺杂制度。特别是预测的FS拓扑被发现是在良好的符合相应的实验数据。我们发现测量的正电子湮没辐射（2D-ACAR）谱的二维角相关和基于DFT的计算之间类似的定量协议。然而，无论是在理论上还是在实验上，2D-ACAR都没有给出扩展动量空间中FS的清晰特征。
Ultrafast Two-Dimensional Spectroscopy Uncovers Ubiquitous Electron-Paramagnon Coupling in Cuprate Superconductors
Università Cattolica del Sacro Cuore（天主教神圣之心大学）；ILAMP (Interdisciplinary Laboratories for Advanced Materials Physics), Università Cattolica del Sacro Cuore（天主教神圣之心大学先进材料物理跨学科实验室）；KU Leuven（荷语鲁汶大学）；CNR-INO (National Institute of Optics)（意大利国家研究委员会光学研究所）；University of Brescia（布雷西亚大学）；“Sapienza” University of Rome（罗马第一大学）；Swinburne University of Technology（斯威本科技大学）
Electronic Structure of Ce-Doped and -Undoped Nd$_2$CuO$_4$ Superconducting Thin Films Studied by Hard X-ray Photoemission and Soft X-ray Absorption Spectroscopy
Dynamic spin-response function of the high-temperature Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ superconductor form angle resolved photoemission spectra
我们介绍了一种计算动态响应函数的形式主义使用实验单粒子格林函数来自角分辨光电子能谱（ARPES）。作为这个过程的一个例子，我们估计了铜氧化物超导体Bi $_2$ Sr $_2$ CaCu $_2$ O $_{8+δ}$的动态自旋响应.我们发现很好的协议与超导态中子数据，特别是$(π,π)$共振与其不寻常的“反向磁振子”的色散。我们预计我们的形式主义也将是有用的解释从其他光谱，如光学和拉曼响应的结果。
