Giant tunneling anomalous Hall conductance in topological insulators

We theoretically investigate the tunneling transport across a magnetic barrier modulated by a top gate potential on the surface of a three-dimensional topological insulator. In the presence of a magnetization component along the bias direction, a finite tunneling anomalous Hall conductance (TAHC), transverse to the applied bias, develops. Depending on the strengths of the magnetization and gate potential, the system can exhibit a giant anomalous Hall angle, with the TAHC exceeding the longitudinal tunneling conductance. Moreover, we predict the existence of a negative differential TAHC even when the longitudinal differential conductance remains positive.