The odd-parity altermagnetism induced reconstruction of the Chern-insulating phase in Haldane-Hubbard model

TL;DR

This paper demonstrates how odd-parity altermagnetism in the Haldane-Hubbard model reconstructs local topological features without changing the overall Chern number, revealing spin and valley selective phenomena.

Contribution

It uncovers the role of odd-parity altermagnetism in topological phase reconstruction and its effects on Berry curvature, edge states, and optical responses in the Haldane-Hubbard model.

Findings

Local topology is significantly reconstructed by odd-parity ALM.

Berry curvature becomes spin and valley selective.

Hall conductivity remains quantized despite local reconstructions.

Abstract

Odd-parity altermagnetism(ALM) extends compensated collinear magnetism beyond the even-parity spin splitting of conventional altermagnets, but its role in correlated topological phases remains largely unexplored. Using the cluster slave-spin method, we show that the odd-parity ALM appearing in the ALM Chern-insulating phase of Haldane-Hubbard model significantly reconstructs the local topology in the conventional Chern-insulating phase, while the total Chern number remains unchanged compared to the Chern-insulating phase. The Berry curvature becomes spin and valley selective; zigzag ribbons develop chiral-symmetry-breaking edge states; while armchair ribbons remain inversion symmetric. The optical response mirrors this separation between the local reconstruction and the global topology: low-energy spectra are governed by quasiparticles near the gap, whereas the low-frequency Hall conductivity stays quantized, $\sigma_{\rm T\uparrow}(\Omega\to 0)=\sigma_{\rm T\downarrow}(\Omega\to 0)=e^2/h$. These results establish the Haldane-Hubbard model as a minimal correlated platform for odd-parity altermagnetic topology.