Topological superconductivity in a Hubbard model for twisted bilayer cuprates

TL;DR

This paper explores how topological superconductivity emerges in a twisted bilayer cuprate Hubbard model, revealing doping-dependent topological phases with high Chern numbers and chiral edge states.

Contribution

It demonstrates the doping-sensitive emergence of topological phases with high Chern numbers in a correlated Hubbard model for twisted bilayer cuprates.

Findings

Chern number is ±8 in electron-doped regime at U/t=3.85.

Topological phases depend strongly on doping level.

Edge states exhibit chirality consistent with the bulk topology.

Abstract

We investigate the emergence of nontrivial topology in a twisted cuprate bilayer described by the Hubbard model in the weak-interaction regime. Our results show that the topological character depends sensitively on the doping level. For $U/t=3.85$, the Chern number assumes a value of $\pm 8$ in the electron-doped case, whereas it vanishes (0) in the hole-doped regime. The presence of nontrivial topology is further supported by an analysis the associated edge states and their chirality in a finite-width geometry, while keeping full correlations.