Revisitation of superconductivity in K${}_2$Cr${}_3$As${}_3$ based on the six-band model

Abstract

We investigate the pairing symmetry of the newly synthesized quasi-one-dimension K${}_2$Cr${}_3$As${}_3$ superconductor based on the six-band model. We adopt standard random-phase-approximation to study the Hubbard-Hund model of the system. Our results confirm the conclusions obtained from our previous three-band model: the triplet $p_z$ and $f_{y^3-3x^{2}y}$ wave pairings serve as the leading pairing symmetries in the weak and strong Hund's rule coupling regimes, respectively. For physically realistic parameters, the triplet $p_z$-wave pairing driven by ferromagnetic fluctuations is the leading pairing symmetry of the system. The consistency between the results of these two models suggests that the obtained $p_z$-wave pairing symmetry is physical and model-independent.

6 pages, 6 figures