Ferrimagnetism of ultracold fermions in a multi-band Hubbard system

• URL: http://arxiv.org/abs/2404.17555v1
• Date: Fri, 26 Apr 2024 17:33:26 GMT
• Title: Ferrimagnetism of ultracold fermions in a multi-band Hubbard system
• Authors: Martin Lebrat, Anant Kale, Lev Haldar Kendrick, Muqing Xu, Youqi Gang, Alexander Nikolaenko, Subir Sachdev, Markus Greiner,
• Abstract summary: We report on signatures of a ferrimagnetic state realized in a Lieb lattice at half-filling. We demonstrate its robustness when increasing repulsive interactions from the non-interacting to the Heisenberg regime. Our work paves the way towards exploring exotic phases in related multi-orbital models such as quantum spin liquids in kagome lattices and heavy fermion behavior in Kondo models.
• Score: 34.95884242542007
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Strongly correlated materials feature multiple electronic orbitals which are crucial to accurately understand their many-body properties, from cuprate materials to twisted bilayer graphene. In such multi-band models, quantum interference can lead to dispersionless bands whose large degeneracy gives rise to itinerant magnetism even with weak interactions. Here, we report on signatures of a ferrimagnetic state realized in a Lieb lattice at half-filling, characterized by antialigned magnetic moments with antiferromagnetic correlations, concomitant with a finite spin polarization. We demonstrate its robustness when increasing repulsive interactions from the non-interacting to the Heisenberg regime, and study its emergence when continuously tuning the lattice unit cell from a square to a Lieb geometry. Our work paves the way towards exploring exotic phases in related multi-orbital models such as quantum spin liquids in kagome lattices and heavy fermion behavior in Kondo models.

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