Meng Cheng (Assistant Professor of Physics) has been awarded an NSF Career Award, “Interplay of Symmetry and Topology in Condensed Matter Systems” to start April 1, 2019.
This CAREER award supports theoretical research and education in novel quantum phases of matter. Interacting many-electron systems, such as those found in a great variety of materials, are distinguished in that they exhibit emergent behaviors and properties that do not manifest in systems comprised of only few particles. The resulting rich variety of phases of matter with wildly different physical properties, e.g. conducting vs. insulating, many forms of magnetism, etc., underlie important technological applications of solid-state materials. An organizing principle that has proven extremely successful for describing conventional phases of matter is based on the notion of symmetry. However, exotic phases of matter have been discovered recently that transcend conventional wisdom and which are enabled by quantum-mechanical effects and strong interactions. Examples include the fractional quantum Hall effect that occurs when electrons are confined in a plane in an external magnetic field, and liquid-like states of magnetic moments in magnetic materials. These new phases of matter have remarkably rich and ordered, in a sense, internal structure, which is termed “topological order”.
This project aims to advance the theoretical understanding of topologically ordered phases. The PI will investigate how the interplay between symmetry and topological order gives rise to new quantum phenomena, by developing a theoretical framework to systematically study topological phenomena in the presence of symmetries and to characterize new quantum phases of matter enriched by symmetries. With these insights the PI will also explore new ways to probe topological order in experiments.
The project will achieve broad impact beyond the condensed matter community, as the research touches on problems that are of fundamental interest in related fields, such as high-energy physics and mathematics. Beyond research, the project will seek to enrich physics education in local communities with coordinated outreach activities. Through integration with the Pathways to Science program at Yale, the outreach activities supported by this project will provide opportunities to middle- and high-school students from underrepresented groups in physics and STEM-related fields, as well as to the general public, aiming to elucidate the physics underlying this research, and more broadly to promote awareness of cutting-edge research on quantum materials.