The observation of an anomalous Hall effect in altermagnetic ruthenium dioxide

The Hall effect is a conduction phenomenon discovered by physicist Edwin Herbert Hall that describes the development of a transverse electric field in solid materials carrying electric current that are placed in a magnetic field perpendicular to this current. In the 1950s, Martin Karplus and Joaquin Mazdak Luttinger showed that an anomalous Hall conductivity could also be observed in ferromagnetic metals with broken time-reversal symmetry.