A microscopic study of boundary superconducting states on a honeycomb lattice

TL;DR

This paper investigates how edges and corners in honeycomb lattice nanostructures influence boundary superconductivity, revealing that atomic boundary structures can significantly enhance or suppress superconducting properties at a macroscopic level.

Contribution

It provides a microscopic analysis of boundary effects on superconductivity in honeycomb lattices, highlighting the dependence on atomic boundary structures.

Findings

Boundary edges can enhance or suppress superconducting gaps.

Critical temperatures differ at boundaries compared to bulk.

Atomic boundary structure strongly influences superconducting correlations.

Abstract

We address the problem of boundary s-wave superconductivity on rectangular honeycomb lattices: nanoflakes, armchair and zigzag nanotubes. We discuss how the presence of edges and corners in these systems can significantly alter the superconducting correlations at a macroscopic length scale, leading to either nontrivial enhancement or suppression of the superconducting gap value near the boundaries. This in turn results in different critical temperatures of the gap closure at boundaries compared to the bulk gap. The effects are macroscopic but strongly depend on the atomic-level structure of the boundaries.