Three-body problem in a multiband Hubbard model
arXiv:2201.13139 · doi:10.1103/PhysRevA.105.063310
Abstract
We consider the three-body problem in a generic multiband lattice, and analyze the dispersion of the trimer states that are made of two spin- fermions and a spin- fermion due to an onsite attraction in between. Based on a variational approach, we first obtain the exact solution in the form of a set of coupled integral equations, and then reduce it to an eigenvalue problem. As an illustration we apply our theory to the sawtooth lattice, and numerically show that energetically-stable trimers are allowed in a two-band setting, which is in sharp contrast with the single-band linear-chain model. In particular we also reveal that the trimers have a nearly-flat dispersion when formed in a flat band, which is unlike the highly-dispersive spectrum of its dimers.
7 pages with 3 figures; to appear in PRA
References in corpus (9)
- The Hubbard Model
- The Hubbard model: A computational perspective
- Observation of an Efimov spectrum in an atomic system
- Exotic electronic states in the world of flat bands: from theory to material
- Low-energy three-body dynamics in binary quantum gases
- Observation of flat band for terahertz spoof plasmon in metallic kagomé lattice
- Pairing and superconductivity in quasi one-dimensional flat band systems: Creutz and sawtooth lattices
- Two-body problem in a multiband lattice and the role of quantum geometry
- Effective-mass tensor of the two-body bound states and the quantum-metric tensor of the underlying Bloch states