Superconducting Transitions in Flat Band Systems

Abstract

The physics of strongly correlated quantum particles within a flat band was originally explored as a route to itinerant ferromagnetism and, indeed, a celebrated theorem by Lieb rigorously establishes that the ground state of the repulsive Hubbard model on a bipartite lattice with unequal number of sites in each sublattice must have nonzero spin S at half-filling. Recently, there has been interest in Lieb geometries due to the possibility of novel topological insulator, nematic, and Bose-Einstein condensed (BEC) phases. In this paper, we extend the understanding of the attractive Hubbard model on the Lieb lattice by using Determinant Quantum Monte Carlo to study real space charge and pair correlation functions not addressed by the Lieb theorems.

References in corpus (7)

• Nearly-flat bands with nontrivial topology
• Flat bands and Wigner crystallization in the honeycomb optical lattice
• Topological Insulators on the Lieb and Perovskite Lattices
• Topological Phases for Fermionic Cold Atoms on the Lieb Lattice
• Bose condensation in flat bands
• The $p_{x,y}$-orbital counterpart of graphene: cold atoms in the honeycomb optical lattice
• Topological flat band models with arbitrary Chern numbers

Cited by in corpus (1)

• Geometry Dependence of the Sign Problem