Understanding electronic correlations in quantum materials
Engineering co-related systems with on-demand emergent properties are critical for quantum Information Science (QIS). The relationship between four fundamental degrees of freedom, lattice, spin, charge, and orbitals, control the emergent properties in quantum materials such as spin-orbit coupling, Jahn Teller effect, etc. Analytical electron microscopy, especially scanning transmission electron microscopy – electron energy loss spectroscopy (STEM–EELS), is useful for measuring these correlated properties from the nanoscale down to the atomic scale. However, the experimental challenges of excessive beam damage, low-temperature measurements, and extracting signal from noisy spectra have limited the STEM–EELS research in quantum materials. The recent installation of a K3® direct electron detector at the back end of the GIF camera has overcome a few of those limitations.
In this webinar, we will use perovskite oxides and two-dimensional examples to highlight the utility of Gatan’s K3 direct electron detector in imaging electronic correlations. The webinar is broadly divided into two sections. First, we will highlight the recent developments in fast chemical mapping, differential chemical mapping, orbital hybridization mapping, and crystal field mapping at the oxide interfaces using core-loss EELS. Second, we will unravel the capability of the K3 to pull out subtle excitonic signatures via low-loss EELS in moiré two-dimensional heterostructures, enabling first-of-a-kind nanoscale intralayer mapping at low temperatures. In the end, we will also propose some future experiments enabled by direct electron detectors that could improve the data interpretation and unravel novel electronic states in quantum materials.
Presenter
Sandhya Susarla, Assistant Professor, School for Engineering of Matter, Transport and Energy, Arizona State University