Probing k-Space Alternating Spin Polarization via the Anomalous Hall Effect

Abstract

We propose probing the momentum-space alternating spin polarization of an altermagnet by interfacing it with a topological-insulator surface. The altermagnet induces a momentum-dependent, sign-alternating Dirac mass, producing an alternating half-quantized anomalous Hall effect. Measuring the Hall conductance can reveal local and global momentum-space magnetic moment distributions.