Global topology from local defects
Itmar Kimchi
Abstract
Defects are always present in solid state materials and can even offer useful tuning knobs, as with semiconductor impurity doping. I will present our group’s recent theoretical results showing how quantum-entangled or topological systems can enable local defects to produce surprising global effects. The results include a chiral spin liquid instability for the Kitaev honeycomb model with crystallographic defects; an experimental collaboration finding several sharp spectral lines attributable to disorder; and a theoretical framework for how localized Hamiltonian modifications or impurities can produce new topological phase transitions, even in non-topological band insulators, through the formation of topological impurity bands.
Bio
Dr. Itamar Kimchi received his PhD from UC Berkeley in 2015 and did postdoctoral work as a Pappalardo Fellow at MIT and as a National Research Council Fellow at NIST Boulder (the National Institute of Standards and Technology) before joining Georgia Tech in 2021. Dr. Kimchi was awarded an Early Career Award by the Department of Energy in 2024 and was promoted to Associate Professor in 2026. The Kimchi group enjoys doing research in the theory of quantum matter by mixing numerical computations and experimental collaborations to pursue conceptual discoveries.
