Agenda

Past colloquia and seminars

04
Feb

Generalized Nagaoka ferromagnetism accompanied by flavor-selective Mott states in the SU(N) Fermi-Hubbard model

Academic or specialist Seminar

I will present our recent theoretical study on ferromagnetic instabilities in the SU(N) Fermi-Hubbard model on a hypercubic lattice using dynamical mean-field theory [1,2]. Focusing on the SU(3) case near 1/3 filling, we discover a distinct particle-hole asymmetry in the magnetic order. Specifically, hole doping stabilizes a ferromagnetic phase where a single flavor becomes dominant, adiabatically connecting to the SU(3) Nagaoka state, whereas particle doping induces a novel ferromagnetic phase characterized by two dominant flavors. We further elucidate that the transitions between these ferromagnetic and paramagnetic phases are of the first order and are accompanied by a flavor-selective Mott state, where specific flavors become localized while the other remains itinerant. I will also discuss the extension to the SU(4) case, where six distinct types of ferromagnetic orders emerge, highlighting the rich magnetic phase diagrams driven by increased internal degrees of freedom. Finally, the general particle-number configurations of ferromagnetic phases in the SU(N) Fermi-Hubbard model will be addressed.

[1] Juntaro Fujii, K.Y., Akihisa Koga arXiv:2512.01264

[2] Juntaro Fujii, K.Y., Akihisa Koga Phys. Rev. B 112, 115136 (2025)


When? 04.02.2026 11:00
Where? PER 08 2.73
Chemin du Musée 3, 1700 Fribourg 
speaker Kazuki YAMAMOTO
Institute of Science Tokyo, Department of Physics
Contact Département de physique
Prof. Philipp Werner
philipp.werner@unifr.ch
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