Colloquia

SDSU Department of Physics Colloquium

Speaker:
Prof. Tzer Han Tan
Department of Physics, University of California San Diego

Abstract:
Many-body physics asks how collective behavior emerges from interactions among simple components. In nonequilibrium systems, this connection becomes especially rich because interactions can generate motion, organization, and dynamical states far from equilibrium. Here, we ask a different question: can the microscopic rules themselves be learned so that a many-body system acquires a desired function? To address this, we developed a minimal experimental platform of active robotic chiral spinners, inspired by living chiral crystals, with long-range medium-mediated coupling and tunable nonreciprocal interactions. Using this platform, we show that reinforcement learning can discover local interaction laws that produce coherent collective motion. Remarkably, the resulting dynamics organize around a small number of collective modes that can be understood in terms of symmetry-resolved interaction components at the microscopic level. More broadly, this work shows how machine learning can be used as a discovery tool to uncover organizing principles of nonequilibrium many-body physics.

Bio:
Tzer Han Tan is an Assistant Professor of Physics at UC San Diego. He leads a research lab developing living and synthetic active matter systems to better understand physical principles that underlie complexity in collective behavior. Before joining UC San Diego, he was a ELBE Postdoctoral Fellow at the Max Planck Institute for Physics of Complex Systems. Tzer Han received his Ph.D. in Physics at MIT and his B.S. in Applied and Engineering Physics at Cornell University. Tzer Han has received the William A. Lee Chancellor's Endowed Junior Faculty Fellowship and the Hellman Fellowship.

Note:
Coffee and cookies will be served at 1:50 PM. This colloquium is supported partly by IRA funds.