Robust Superconductivity in Quasi-One-Dimensional Multiband Materials

TL;DR

This paper demonstrates that quasi-one-dimensional multiband superconductors can maintain robust superconductivity even with shallow higher-dimensional bands, expanding understanding of superconductivity in chain-like materials.

Contribution

It reveals that Q1D fluctuations are suppressed in multiband systems even with shallow bands, providing new insights into the robustness of superconductivity in chain-like materials.

Findings

Q1D fluctuations are weakened with shallow bands.

Robust superconductivity observed in A2Cr3As3 materials.

Impact of higher-dimensional bands on Q1D superconductivity.

Abstract

Recently it has been demonstrated that the pair-exchange coupling of quasi-one-dimensional (Q1D) bands with conventional higher-dimensional bands in one multiband superconducting material can result in the formation of robust aggregate pair condensate. In particular, it has been found that the Q1D thermal pair fluctuations are suppressed in the presence of deep conventional band(s), where the Fermi level is much larger than the characteristic cut-off energy. Here we report that impact of the Q1D fluctuations is significantly weakened even in the presence of nearly shallow higher-dimensional band(s), which shed new light on robust superconducting state observed in emerging chain-like-structured superconducting materials A_2Cr_3As_3 (A = K, Rb, Cs).