Embodiments are directed to a sensor having a first electrode, a second electrode and a detector region electrically coupled between the first electrode region and the second electrode region. The detector region includes a first layer having a topological insulator. The topological insulator includes a conducting path along a surface of the topological insulator, and the detector region further includes a second layer having a first insulating magnetic coupler, wherein a magnetic field applied to the detector region changes a resistance of the conducting path.