Breaking Resolution Limits using Computational Lenses for Topological Materials

Electrons play a pivotal role in stabilizing matter, but they are also tools that can reveal the underlying physics of complex systems from high energy physics to condensed matter. Electrons can be used as imaging probes, where properties of matter such as ferroelectricity, magnetism or topology can be observed atom-by-atom. In this talk, I will discuss a new type of electron probe which can image orbital angular momentum, torque transfer and chiral order of topological structures in ferroelectrics. I will also show how electron ptychography, an iterative computation imaging technique, can improve resolution beyond the numerical aperture of the electromagnetic lenses to the sub-angstrom limit in a conventional electron microscope. Using this technique, we essentially develop a ‘computation lens’ approach to imaging, opening opportunities to explore new physics in emergent materials beyond physical lenses in a cost-effective manner, and thus expanding access to high-resolution imaging approaches to a broader range of institutions.