Emergent multicomponent phases and odd parity in unconventional superconductors

我们的联合理论和实验建议的总体目标是更好地理解在非常规超导体中多轨道，强自旋轨道耦合与潜在的非平凡拓扑结构的存在下，以及电子-电子和配对相关的微妙相互作用的形成紧急多组分相。 例子范围从适度相关的系统，如铜，铌，或Sr插入Bi 2Se 3与奇宇称超导强相关的系统，如铁基超导体和Sr 2 RuO 4。该计划的主要目标之一是从理论和实验上探索这些态的配对涨落的热力学和光谱特征，以及它们与磁、轨道和电子不稳定性的竞争，并揭示它们的微观起源和对超导性的反馈。我们计划研究的奇宇称超导体的形成Bi 2Se 3和相关的（邻近诱导）系统中的电子相关性是温和的探索的作用，货车的范德华力在形成的库珀配对。另一方面，我们计划研究铁基硫族化合物超导体和Sr 2 RuO 4，其中强电子关联与强自旋轨道耦合一起发生。很明显，强的电子相关性使它们的理论和实验研究在技术上更具挑战性。在这里，我们计划进一步发展的相敏技术，以确定在多轨道情况下的超导带隙的相结构和研究的非平凡带拓扑结构的潜在作用。奋进的具体目标是开发一个真正的微观描述可用的新的实验，描述这些系统的热力学和光谱（STM）功能的定量水平。

The overall goal of our joint theoretical and experimental proposal is to better understand the formation of emergent multicomponent phases in unconventional superconductors in the presence of multiple orbitals, strong spin-orbit coupling with potentially non-trivial topology of the band structure, and the delicate interplay of electron-electron and pairing correlations. The examples range from moderately correlated systems such as Cu, Nb, or Sr intercalated Bi2Se3 with odd parity nematic superconductivity to strongly-correlated systems such as iron-based superconductors and Sr2RuO4. One of the main objectives of this proposal is to explore theoretically and experimentally the thermodynamic and spectroscopic features of the pairing fluctuations of these states and their competition with magnetic, orbital, and nematic instabilities and to reveal their microscopic origin and feedback on superconductivity. We plan to study the formation of the odd-parity nematic superconductivity in Bi2Se3 and related (proximity-induced) systems where electronic correlations are moderate exploring the role of van der Waals forces in the formation of the Cooper-pairing. On the other hand we plan to investigate the Fe-based chalcogenide superconductors and Sr2RuO4, where strong electronic correlations occur together with strong spin-orbit coupling. Clearly strong electronic correlations make their theoretical and experimental investigation technically more challenging. Here, we plan to further develop the phase sensitive technique to determine the phase structure of the superconducting gap in multiorbital case and study the potential role of non-trivial band topology. The specific objective of the endeavor is to develop a genuine microscopic description of the available novel experiments that describes thermodynamic and spectroscopic (STM) features of these systems on a quantitative level.