Quantum Monochromated EELS: Accessing Emergent Phenomena in The Electron Microscope with High Spatial and Spectral Resolution

Monochromated electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) is a technique that has achieved the ability to combine ultrahigh energy and spatial resolution simultaneously. As a result, a new wave of experiments on ultralow energy excitations, such as phonons, phonon-polaritons, molecular vibrations, shallow electronic structure, and infrared optical excitations have achieved exciting results in the STEM. <br/> <br/>Here, I will show recent work at ORNL on the monochromated EELS of quantum materials with an emphasis on the emergence electronic structure and quasiparticles generated from coupling between layers in quantum dot networks and oxide superlattices. I will also focus on recent efforts at ORNL to incorporate cryogenic cooling alongside monochromated EELS in the analysis of quantum materials and some of the challenges and progress that has been made on the spectroscopy of low-dimensional quantum materials at liquid nitrogen temperatures.