As condensed matter theorists, one of our main goals is to understand how the microscopic behavior of a very large number of atoms or molecules is related to the macroscopic properties of solids and liquids. While this certainly applies to objects common in our daily lives, such as kitchen salt or water, we are also interested in quantum versions of solids, liquids, and gases. For example, the properties of many metals are well described in terms of a gas of nearly independent electrons, whereas in other systems the electron-electron interaction is so significant that they behave as strongly correlated quantum liquids.
At first sight, the problem may seem deceivingly straightforward, after all, the ions and electrons forming the atoms only talk to each other via the good old electrostatic repulsion. However, it turns out that the quantum-mechanical collective behavior of condensed matter systems is often very different than just the simple sum of its constituents. This phenomenon, called emergence, is behind many unique and fascinating properties, among which superconductivity is perhaps the best known.Condensed matter theory is a very broad area, that ranges from concrete applications to more abstract models. At the University of Minnesota, we have a vibrant condensed matter theory group working on a diverse set of topics, such as quantum materials, superconductivity, liquid crystals, quantum magnets, topological quantum matter, disordered systems, and non-equilibrium physics. We also enjoy frequent collaborations with the condensed matter experimental group, creating an engaging atmosphere to perform research in this field.