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空间显微镜这一新概念的软X射线角分辨光电子能谱(SX-ARPES)仪器。为此，我们将建造这样一台在高光子能量下工作的仪器，并在钻石光源的i09软X射线光束线上进行测试和使用。该仪器基于一种特殊的物镜，针对动量空间成像进行了优化，有助于对固体进行真正的二维电子能带结构绘制，大大提高了检测效率。因此，这种新的方法克服了传统SX-ARPES众所周知的低计数率，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，提供对体电子结构和掩埋界面的访问。作为例子，我们想用选定的氧化物异质结构作为试验台，研究它们引人入胜的电子界面性质。这里提出的k空间显微镜有可能给光电子能谱领域带来革命性的变化，并将其应用于以前被认为无法通过这项技术访问的新领域。

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.