Unconventional anomalous Hall effect from magnetization parallel to the electric field

Abstract: In the anomalous Hall effect (AHE), the magnetization, electric field and the Hall current are presumed to be mutually vertical to each other. In this work, we propose an unconventional AHE where the magnetization, the electric field and Hall current stay inside the same plane. Such an AHE is odd under time-reversal and exists even when the magnetization is parallel to the electric field or Hall current, different from the planar Hall effect which is even under time-reversal. Here, we term it parallel anomalous Hall effect (PAHE). We reveal that the PAHE exists when all the point group rotational and reflection symmetries are broken where the Berry curvature field is not necessarily parallel to the magnetization axis. We further demonstrate the PAHE in a ferrimagnetic Weyl semimetal FeCr$_2$Te$_4$.