Quantum metric and effective mass of a two-body bound state in a flat band
Superconductivity
2019-01-02 v1 Quantum Gases
Abstract
We consider two-body bound states in a flat band of a multiband system. The existence of pair dispersion predicts the possibility of breaking the degeneracy of the band and creating order, such as superconductivity. Within a separable interaction potential approximation, we find that finiteness of the effective mass of a bound pair is determined by a band structure invariant, which in the uniform case becomes the quantum metric. The results offer a simple foundation to understand and predict flat band superconductivity. We propose an experiment to test the interaction-induced pair motion.
Keywords
Cite
@article{arxiv.1810.09870,
title = {Quantum metric and effective mass of a two-body bound state in a flat band},
author = {Paivi Torma and Long Liang and Sebastiano Peotta},
journal= {arXiv preprint arXiv:1810.09870},
year = {2019}
}