Due to their large bulk band gap, bismuthene, antimonene, and arsenene on a SiC substrate offer intriguing new opportunities for room-temperature quantum spin Hall (QSH) applications. We show that for experimentally relevant armchair nanoribbons, we find a distinct behavior of the gap induced in the QSH edge states for out-of-plane magnetic fields (a few meV) versus in-plane magnetic fields (negligible gap) which is the hallmark of their topological origin. Further, we predict experimentally testable fingerprints of this behavior in the LDOS and in ballistic magnetotransport.
