Fabry-Pérot resonant vortexes and magneto conductance in topological insulator constrictions with magnetic barriers

The physics of topological systems has received great attention since its electronic transport properties show prominent applications in many fields (e.g.spintronics). The key ingredient is the band inversion, usually due to strong spin-orbit couplings, and its main feature is the robustness of the edge states against non-magnetic impurities. An interesting approach to investigate these properties is via a geometric manipulation of the system. Here, we study the transport in one-dimensional (1D, ribbon) constrictions of two-dimensional (2D) systems, which leads to interesting phenomena, such as quantum interference between edge states. In particular, in our analysis, this process drives the constriction region of the system to show Fabry-Pérot resonance peaks in the conductance. Such effect rises due to the velocity mismatch between the edge states in the constriction and the perfect leads. We show that magnetic barriers inside that constriction allow us to manipulate these peaks and obtain significant changes in the system spin-resolved magnetoconductance.