Atomic scale dynamics of correlated materials and emergent quantum states

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Investigation of new phases of matter often reveals previously unknown physics; it also commonly leads to previously unimaginable technological breakthroughs. At present great attention is directed towards high-temperature superconductors, single atom thick sheets, and exotic magnetic materials. Each of these materials holds promise to revolutionize our world via energy and computer applications. Each also involves very complex networks of interacting atoms responsible for collective magnetic or electronic properties fundamentally different from the usual metals or magnets. The complexity, however, greatly holds back understanding and control of these new properties. This research program is designed to unravel the exact details of atomic interactions, seeking answers critical to realizing the technological potential of the materials as well as elucidating the underlying physics. In many senses the ultimate measurement is to make a movie of a material responding to an external stimulus. Not only does this simulate technological devices, but measuring the dynamic response of a material provides a much more stringent test of our understanding than static experiments. However, in these strongly interacting materials, the dynamics of interest happen on the time scale of a few quadrillionths of a second and also vary on the atomic scale. Creating ultrafast atomic movies is one of the grand challenges facing science. Recent advances in time-resolved scanning tunneling microscopes (TR-STMs) have revealed a path to these extraordinary experiments for electronic systems. This research program applies TR-STMs to the investigation of atomic-scale dynamics in materials with magnetic and electronic collective states. The nature of a scanning tunneling microscope allows direct imaging of electronic states. Adding pulsed laser techniques enables ultrafast movie making; measuring the response of each individual atom in a crystal to a stimulus. This capability significantly reduces measurement ambiguity, caused by very complex material structure or the presence of disorder, compared to techniques without atomic resolution. The focus of the program is on the study of dissipation in magnetically interacting materials. This includes how energy is lost and how coherence among a group of atoms acting collectively is destroyed. The results have important implications for high efficiency magnetic computing, and spin based quantum computing. A great deal more, beyond magnetism, can be studied in this program. This opens the door to collaborations within and outside Canada studying materials such as high temperature superconductors. Pursuing an atomic understanding of emergent quantum states will provide invaluable experience to a new generation of young Canadian scientists who will lead science and industry forward in the revolutionary applications of quantum materials.