This instrumentation funding will support the acquisition of cryogenic UHV facilities for a combined ARPES-STM system for research and education of novel materials. This unique combination of STM and ARPES will unite the two powerful capabilities of obtaining spatial and momentum resolved data. It will facilitate for the first time a direct comparison between the two spectroscopies measured on the same surface of many novel materials, including high-TC superconductors, organic superconductors, and nano-materials, whose surface can easily vary from sample to sample. The proposed research activities on this instrument will advance significantly our understanding of Luttinger liquids, Mott physics, and novel superconductivity, all of which are the essential parts of modern condensed matter physics. This project will also make a significant impact on the education of undergraduate, graduate students, and post-docs by introducing them to exciting new materials, cutting-edge techniques, and fundamental condensed matter physics.
A scanning tunneling microscope (STM) probes atomic structure and local electron density by using a sharp metallic tip that can be positioned close to the surface of a material. Its powerful capability comes from its capacity for sub-atomic spatial resolution. Another important probe to study electronic states in materials is angle-resolved photoelectron spectroscopy (ARPES), which measures photon-excited electrons from a sample surface according to their emission angles, or momenta. By combining these two complementary techniques, one can obtain almost complete information about electrons which determine the properties of a material. This is what we want to achieve with the support of this instrumentation award, which will provide us cryogenic ultra-high vacuum facilities for a combined ARPES-STM system. Using this combined system, we propose to study many novel materials, including high-TC superconductors, organic superconductors, and nano-materials, in order to advance our understanding of the unusual properties of these materials. This is important both for fundamental physics as well as for potential applications. This project will also make a significant impact on education of students by introducing them to exciting new materials, cutting-edge techniques, and basic science.
