铁基超导体角分辨光电子能谱及电子拉曼光谱的研究

项目名称： 铁基超导体角分辨光电子能谱及电子拉曼光谱的研究

项目编号： No.11274362

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： Pierre Richard

作者单位： 中国科学院物理研究所

项目金额： 91万元

中文摘要： 铁基超导体研究是现代凝聚态物理领域的重要课题，对其深入了解可以带来电子器件的革命。铁基超导体令人感兴趣的电子性质在于它们的电子能带结构，特别是费米能级附近的电子态，这些电子态是非局域化的，因此迫切需要对铁基超导体动量空间的电子结构开展全面的研究。尽管角分辨光电子能谱(ARPES)是一种能够直接获取费米面拓扑结构，超导能隙大小和对称性，以及k空间分辨的能带结构的有力工具，然而，ARPES是一种表面敏感的分析技术，通常需要其他实验技术得到的结果作为参照。我们拟结合ARPES和拉曼散射(Raman)两种技术来表征铁基半导体，着重表征超导能隙，超导能隙能直接反映配对机制。得益于Raman光学选择定则和激光的偏振可调节性，我们可以获得带有部分动量信息的超导材料体相的超导能隙性质，从而为ARPES数据提供很好的佐证。我们深信获得的大量的数据能够进一步探讨和求证这些材料中的超导电子配对机制。

中文关键词： 角分辨光电电子能谱；拉曼散射；铁基超导体；电子结构；Weyl半金属

英文摘要： Fe-based superconductivity is possibly the first important topic in modern condensed matter physics for which China is widely recognized abroad as the main World leader. This field is of strategic importance since the understanding of this new family of high-temperature superconductors is believed to lead to the synthesis of compounds with higher critical temperature that will pave the way for a revolution in electronic devices that may equal the revolution once introduced by semi-conductors. The electronic properties of the Fe-based superconductors are dominated by the electronic states in the vicinity of the Fermi level. These states are not localized and disperse in the momentum space. To characterize them completely, it is thus necessary to use probes sensitive to the momentum space. With its capability to resolve the electronic structure of materials in the momentum space, Angle-Resolved Photoemission Spectroscopy (ARPES) is a powerful toll that allows direct momentum characterization of such dispersive electronic states. In particular, it is suitable to determine the Fermi surface topology of materials and the momentum profile of superconducting gaps, which characterize the superconducting pairing mechanism. However, ARPES is mainly a surface sensitive technique, and it is often necessary to support ARPES

英文关键词： angle-resolved photoemission spectroscopy；Raman scattering；Fe-based superconductors；Electronic structure；Weyl semimetals