Ultra-cold atoms: understanding advanced materials with iconic condensed matter

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At the coldest temperatures in the universe, even dilute gases are dominated by quantum mechanics. These fragile gases are in fact quite useful. Like stem cells, ultracold atoms can take on properties dictated by their environment: they can be liquids, solids, or gases; they can be magnetic, insulating, or superconducting. By observing the correlation between system behavior and system parameters, we can learn why materials act as they do. We propose to explore two directions with ultracold atoms. First, we would like to understand the minimal set of conditions for ferromagnetism. What are the essential ingredients? Magnetism has been observed - and even applied in compasses, for instance - for millennia. However a question that has been debated since the 1930s is whether a gas can be magnetic. Nature does not provide us with examples, but ultracold atoms can be tuned to extremely strong interactions. We already have some hints about the answer to this age-old question, but our first results left open several loopholes. Stay tuned for exciting news. Second, we will place our ultracold atoms into a crystalline environment which mimics the basic geometry of cuprate superconductors. Exotic materials such as cuprates pose some of the most important open questions in physics. Theorists have proposed models to explain their properties, but this is a difficult problem: even reduced models have proven difficult to solve. Ultra-cold atoms offer a new hope in our quest to understand exotic materials. By testing the basic theoretical models of superconductivity in a simpler system, we hope to be one step closer to understanding the advanced materials that are so critical to modern technologies.