Guest Speaker: Ehsan Khatami (San Jose State University)
Location: IAMM 310
Zoom Link for Virtual Attendees

Title: Kinetic Magnetism in a Frustrated Fermi-Hubbard System

Abstract: Nagaoka famously proved that introducing a single itinerant charge to the half-filled Fermi-Hubbard model can transform a paramagnetic insulator into a ferromagnet through path interference. Such kinetic magnetism has recently been realized with strongly interacting fermions in a triangular optical lattice [1,2]. In this talk, I will give a quick summary of the experimental findings, including the emergence of Nagaoka polarons as extended ferromagnetic bubbles around particle dopants, and present theory results based on simulations of the model using the numerical linked-cluster expansions in support of these observations on both the square and triangular lattices. Time permitting, I will also discuss how ground state wavefunctions of quantum lattice models, including that for the Nagaoka phenomenon, may be represented and studied by recurrent neural networks.
[1] Lebrat et al., arXiv:2308.12269
[2] Prichard et al., arXiv:2308.12951

Seminar Organizer: Ruixing Zhang Email Ruixing Zhang