Professor Masaki Oshikawa
ISSP, University of Tokyo
Universal Constraints on Quantum Many-Body Systems from Thought Experiments
Location: 1080 Physics Research Building
Faculty Host: Ilya Gruzberg
Abstract: In materials, an immense number of electrons move and interact, making their collective behaviors notoriously difficult to understand. While detailed calculations are ultimately necessary for quantitative predictions, simple “thought experiments” can provide surprisingly powerful, universal constraints that hold regardless of the system’s details. In this talk, I will describe how “flux insertion” arguments lead to illuminating results such as the filling-based exclusion of trivial insulators, a topological quantization of the Fermi sea volume, and the frequency sum rules and Kohn formulae for Drude weights at all orders of nonlinear conductivities.
Bio: Masaki Oshikawa is a theorist whose research spans condensed matter physics, statistical physics, and field theory. After earning his Ph.D. from the University of Tokyo in 1995, he became a Killam Postdoctoral Fellow at the University of British Columbia. He then served as Associate Professor at Tokyo Institute of Technology from 1998 until 2006, when he became a Professor at the Institute for Solid State Physics, University of Tokyo. His scientific contributions have been recognized with several awards and honors, including the Ryogo Kubo Memorial Prize, the Japan Society for the Promotion of Science Prize, and Fellowship of the American Physical Society. Frequently invited to international conferences and workshops, he is known for traveling with his iconic blue folding bicycle, which has accompanied him to 25 countries so far.
