Novel k-space microscope for soft x-ray photoelectron spectroscopy of bulk materials and buried interfaces

本项目旨在开发基于动量或k空间显微镜新概念的软x射线角分辨光电子能谱（SX-ARPES）仪器。为此，我们将构建这样一个在高光子能量下工作的仪器，并在金刚石光源的I09软x射线光束线上进行测试和使用。该仪器基于一个特殊的物镜，优化了动量空间成像，实现了固体的真正二维电子带结构映射，大大提高了检测效率。因此，克服了传统SX-ARPES众所周知的低计数率，这种新颖的方法将允许充分利用高能光电发射的核心优势，即其更大的探测深度，提供了进入大量电子结构和埋藏界面的途径。作为一个例子，我们想用选定的氧化物异质结构作为测试平台，研究它们迷人的电子界面性质。这里提出的k空间显微镜有可能彻底改变光电子能谱领域，并将其应用于以前认为无法通过该技术进入的新领域。

This project aims at the development of instrumentation for soft x-ray angle-resolved photoelectron spectroscopy (SX-ARPES) based on the novel concept of momentum- or k-space microscopy. For this purpose we will construct such an instrument for operation at high photon energies, and test and use it at the I09 soft x-ray beamline of the Diamond Light Source. Based on a special objective lens, optimized for momentum-space imaging, the instrument facilitates true two-dimensional electronic bandstructure mapping of solids with dramatically enhanced detection efficiency. Thereby overcoming the notoriously low count-rates of conventional SX-ARPES, this novel approach will allow to make full use of the central advantage of high-energy photoemission, namely its much larger probing depth, providing access to the bulk electronic structure and to buried interfaces. As case in point we want to use selected oxide heterostructures as testbed and study their fascinating electronic interface properties. The k-space microscope proposed here has the potential to revolutionize the field of photoelectron spectroscopy and open its application to new areas previously not thought to be accessible by this technique.