Scientific Opportunities: Condensed Matter Physics
Strongly Correlated Electron Systems
Understanding the electronic behavior of strongly correlated electron systems is one of the most important problems in condensed matter physics - one that is driving a revolution in the study of solids that behave like Fermi liquids. These solids have electronic degrees of freedom that produce exotic properties. For example, in materials with poor screening properties, such as the doped transition metal oxides, the interaction energy between valence electrons can overwhelm their kinetic energy, causing a strongly coupled many-body ground state. As a result of this strong electron correlation, these materials display a range of useful behaviors, including high-temperature superconductivity, colossal magnetoresistance, and an extreme sensitivity to external perturbations. An example is shown in the figure.
However, in these materials, the laws of solid-state physics are not applicable. In our effort to understand the physics of, for example, high-temperature superconductors, the language we use to discuss condensed matter is itself at issue. Rewriting the laws of solid-state physics is a monumental theoretical task that is one of the "Grand Challenges" in physics today.
For example, physicists need to go beyond the conventional picture of ordered ground states with weakly interacting excitations in order to identify and understand more exotic phases. Identifying and characterizing these new phases will require ultra-low temperatures, high-magnetic fields, and high-pressures that are closely coupled with materials synthesis (especially nanoscale structures). When put with x-ray techniques (scattering, imaging and local probes), these approaches will help to fully elucidate the electronic behavior of many materials.
The high-brightness of NSLS-II will drive advances in energy and real-space resolution of these techniques that will dramatically advance the field of strongly correlated electron systems, announcing a new era in condensed matter physics.
Last Modified: May 2, 2014