Topological Superconductors in Doubly-Coupled Nanowires with Altermagnetism

We theoretically investigate the possibility of engineering topological superconductivity in doubly coupled nanowires integrating proximity-induced superconductivity and altermagnetism. By tuning experimentally accessible parameters, we find four distinct topological superconducting phases: class D, class BDI, and two phases hosting two Majorana zero modes per end, protected respectively by spin-group and magnetic point-group symmetries. Beyond inheriting the advantages of alternating?magnetism induced topological superconductivity, our system provides multiple tuning knobs (e.g., superconducting phase difference and inter-wire coupling) to control topological properties.