Chiral topological superconductivity from quantum anomalous Hall states in ferromagnetic metals
Phys. Rev. B 114, 264502 – Published 2 November, 2026
DOI: https://doi.org/10.1103/rvzx-phch
Abstract
We investigate how additional topologically trivial metallic bands crossing the Fermi level modify the conventional quantum anomalous Hall (QAH)–superconductor mechanism for chiral topological superconductivity in ferromagnetic metals. A four-band model containing an inverted spin-polarized QAH sector and an exchange-split metallic pair is supplemented by spin-singlet -wave pairing and studied in the Bogoliubov–de Gennes (BdG) formalism. Weak pairing produces a gapless or nearly gapless superconducting metal in which chiral boundary channels coexist with bulk quasiparticles and retain a dephasing-enhanced Hall response inherited from the metallic QAH parent state. Strong pairing gaps out the low-energy states derived from the normal-state metallic bands and stabilizes fully gapped two-dimensional chiral topological superconducting phases with BdG Chern numbers and . The evolution between the broad and strong-pairing regimes proceeds through a narrow intermediate phase and is accompanied by a reversal of the net Majorana chirality and a pronounced reconstruction of the orbital texture of the chiral edge states. The fully gapped phases are identified by chiral Majorana ribbon spectra, quantized thermal Hall response, and Andreev transport signatures. Our results extend the QAH-superconductor paradigm to metallic ferromagnets and suggest ferromagnetic superconductors with spin-polarized band inversion as candidate platforms for intrinsic chiral topological superconductivity.