The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.
On Monday, October 20th, 2025 from 11.00 am to 12.00 we will host a seminar by Johan Carlström from KTH.
Kinetic magnetism as a mediator of strong inter-carrier attraction in moiré flat bands
The doped Mott insulator, where charge carriers propagate against a spin background, serves as a paradigmatic model for strongly correlated electronic systems. In this framework, two fundamental energy scales emerge: the kinetic energy, stemming from the delocalisation of charge carriers, and the magnetic energy, driven by super-exchange processes that promote antiferromagnetic order. When the onsite repulsion is strong, super-exchange is suppressed, and spin correlations are predominantly governed by delocalisation—a phenomenon known as kinetic magnetism. In this talk, I will provide a concise introduction to this captivating topic, highlighting recent experimental advances, including those involving moiré materials. I will also discuss my own research, which investigates how kinetic magnetism can mediate attraction between charge carriers, and I will relate these findings to recent experimental observations.