Quantum metric and effective mass of a two-body bound state in a flat band

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2018-12-26
Major/Subject
Mcode
Degree programme
Language
en
Pages
1-5
Series
Physical Review B, Volume 98, issue 22
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 the 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.
Description
Keywords
Condensed Matter - Superconductivity, Condensed Matter - Quantum Gases
Other note
Citation
Törmä , P , Liang , L & Peotta , S 2018 , ' Quantum metric and effective mass of a two-body bound state in a flat band ' , Physical Review B , vol. 98 , no. 22 , 220511 , pp. 1-5 . https://doi.org/10.1103/PhysRevB.98.220511