Revival of superconductivity in a one-dimensional dimerized diamond lattice

TL;DR

This paper investigates how spin-orbit coupling and Zeeman fields influence s-wave superconductivity in a one-dimensional dimerized diamond lattice, revealing conditions under which superconductivity is revived.

Contribution

It introduces a detailed mean-field analysis of superconductivity in a dimerized diamond lattice considering spin-orbit and Zeeman effects, highlighting the revival of superconductivity due to their interplay.

Findings

Spin-orbit coupling and Zeeman splitting individually suppress superconductivity.

Their combined effect can restore superconductivity at charge neutrality.

Superconductivity stability depends on dimerization pattern and external fields.

Abstract

We study an s-wave superconductivity in a one-dimensional dimerized diamond lattice in the presence of spin-orbit coupling and Zeeman field. The considered diamond lattice, comprising of three sublattices per unitcell and having flat band, has two dimerization patterns; the intra unitcell hoppings have the same (opposite) dimerization pattern as the corresponding inter unitcell hoppings, namely, neighboring (facing) dimerization. Using the mean-field theory, we calculate the superconducting order parameter self-consistently and examine the stability of the superconducting phase against the spin-orbit coupling, and Zeeman splitting, dimerization, and temperature. We find that the spin-orbit coupling or Zeeman splitting individually has a detrimental effect on the superconductivity, mostly for the facing dimerization. But their mutual effect revives the superconductivity at charge neutrality point for the facing dimerization.