Using an atomic quantum simulator, scientists at the University of Illinois at Urbana-Champaign have achieved the first-ever direct observation of chiral currents in the model topological insulator, the 2-D integer quantum Hall system.
Topological Insulators (TIs) are arguably the most promising class of materials discovered in recent years, with many potential applications theorized. That's because TIs exhibit a special quality: the surface of the material conducts electricity, while the bulk acts as an insulator. Over the last decade, scientists have extensively probed the microscopic properties of TIs, to better understand the fundamental physics that govern their peculiar behavior.
Atomic quantum simulation has proven an important tool for probing the characteristics of TIs, because it allows researchers greater control and greater possibilities for exploring regimes not currently accessible in real materials. Finely tuned laser beams are used to trap ultracold rubidium atoms (about a billion times colder than room temperature) in a lattice structure that precisely simulates the structure of ideal materials.
Alex An, a physics graduate student working under Assistant Professor Bryce Gadway at Illinois, is lead author of the study, "Direct observation of chiral currents and magnetic reflection in atomic flux lattices," recently published in Science Advances.
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