Pair Density Waves from Local Band Geometry
Abstract
A band-projection formalism is developed for calculating the superfluid weight in two-dimensional multi-orbital superconductors with an orbital-dependent pairing. It is discovered that, in this case, the band geometric superfluid stiffness tensor can be locally non-positive-definite in some regions of the Brillouin zone. When these regions are large enough or include nodal singularities, the total superfluid weight becomes non-positive-definite due to pairing fluctuations, resulting in the transition of a BCS state to a pair-density wave (PDW). This geometric BCS-PDW transition is studied in the context of two-orbital superconductors, and proof of the existence of a geometric BCS-PDW transition in a generic topological flat band is established.
Keywords
Cite
@article{arxiv.2211.09846,
title = {Pair Density Waves from Local Band Geometry},
author = {Guodong Jiang and Yafis Barlas},
journal= {arXiv preprint arXiv:2211.09846},
year = {2023}
}