** This is a new weekly seminar for local condensed matter theory students and postdocs to present their work to one another. Everyone is welcome! If you're interested in presenting at a future seminar, please send a message to This email address is being protected from spambots. You need JavaScript enabled to view it.. **
Speaker: Yan Li, UMD Title:Kinetic Ferromagnetism in the Hubbard Model
Abstract:The Hubbard model is a fundamental framework for understanding strongly correlated electron systems and gaining insights into how interactions between electrons give rise to insulating, magnetic, and even superconducting effects in a solid. It introduces short-range interactions between electrons to the tight-binding model, which only includes a kinetic hopping term and an on-site interaction term. Despite its apparent simplicity, the full phase diagram remains unresolved. Nearly 60 years ago, Nagaoka proved the existence of ferromagnetism when there’s a single dopant from half-filling through kinetic mechanisms. Since then, extensive theoretical and numerical efforts have explored broader conditions under which kinetic ferromagnetism can emerge. In this talk, I will discuss recent theoretical advances in this field, including a polaronic mechanism behind kinetic ferromagnetism and the emergence of such ferromagnetism in open boundary systems.