Higher-order topology driven by -wave magnetic proximity
Phys. Rev. B 114, 245406 – Published 6 October, 2026
DOI: https://doi.org/10.1103/ls5w-pgdc
Abstract
The recent experimental discovery of -wave magnetism opens new avenues for exploring momentum-dependent topological phases. However, whether -wave magnetic proximity can generate higher-order boundary states remains largely unexplored, particularly when an odd in momentum -wave channel induced by magnetic proximity coexists with a finite Zeeman-like perturbation. Here we investigate a quantum spin Hall insulator subjected to these two magnetic terms and show that the resulting higher-order topological phase arises when the Zeeman-like term shifts the helical Dirac crossing to finite momentum and the -wave channel opens a gap at the shifted crossing. Specifically, the Zeeman-like term first shifts the helical Dirac crossing to finite momentum, enabling the -wave channel to generate finite boundary masses. The resulting sign-changing boundary mass term creates domain walls that trap zero-energy corner states. For the family of model Hamiltonians parametrized by , the bound-state positions follow the orientation of the odd-parity form factor along curved boundaries. Our work establishes odd-parity magnetic proximity as a distinct route to higher-order topology in helical systems.