Resonant x-ray scattering and inverse photoemission in superconductors and oxide electronics

现代材料研究的前沿之一是对被广泛归类为量子材料的新一代材料的研究。这些材料可以显示出电子之间的强烈相互作用，这导致了一些现象，这些现象往往与技术相关，而且从根本上挑战了我们对凝聚态物理的理解。这类材料的一个关键例子是铜酸盐和磷酸盐高温超导体。这些材料在高温下表现出超导性，这为发电、运输和储存技术带来了希望，这些技术可以在我们未来的能源基础设施中发挥重要作用。同样，这些材料对我们对材料的理解提出了巨大的挑战，理解高温超导机制和开发用于实际应用的室温超导体的双重目标是物理学中最突出的两个问题。在这些问题的背后，需要理解强关联以及电荷、自旋、轨道和晶格有序现象在量子材料中所起的作用。我们提出的研究计划旨在通过以下几个关键研究流来应对这些重大挑战：1.利用共振软x射线散射研究铜酸盐超导体中的条带有序；2.利用共振x射线反射率研究氧化物界面和多层膜；以及3.利用逆光电子能谱研究量子材料中的电子结构。

One of the forefronts of modern materials research is the study of new generations of materials broadly classified as quantum materials. These materials can exhibit strong interactions between electrons, which leads to phenomena that is often both technologically relevant and fundamentally challenging to our understanding of condensed matter physics. A key example of such materials are the cuprate and pnictide high-temperature superconductors. These materials exhibit superconductivity at elevated temperatures, which holds promise for power generation, transportation and storage technologies that can play an important role in our future energy infrastructure. Equally, these materials present a grand challenge to our understanding of materials and the dual goals of understanding the mechanism of high temperature superconductivity and developing a room temperature superconductor for practical applications are two of the greatest outstanding problems in physics. Underlying these problems is a need to understand the roles that strong correlations and charge, spin, orbital and lattice ordering phenomena have in quantum materials. Our proposed research program aims to tackle these grand challenges by pursuing a few key research streams: 1. Investigating stripe order in cuprate superconductors using resonant soft x-ray scattering; 2. Investigating oxide interfaces and multilayers using resonant x-ray reflectivity, and; 3. Investigating electronic structure in quantum materials using inverse photoemission spectroscopy.