Electronic structure and coexisting topological states in ferromagnetic and antiferromagnetic phases of MnBi₂Te₄ quantum wires

We theoretically investigate the electronic structure of cylindrical magnetic topological insulator quantum wires in MnBi₂Te₄. Our study reveals the emergence of topological surface states in the ferromagnetic phase, characterized by spin-polarized subbands resulting from intrinsic magnetization. In the antiferromagnetic phase, we identify the coexistence of three distinct types of topological states, encompassing both surface states and central states.