Magnetoelectric device read-out schemes based on electric resistivity measurements in heavy metal Hall bar structures

Controlling magnetism by electrical means is a key challenge in the field of spintronics and essential for energy efficient devices in computing. Previously suggested magnetoelectric MRAMs suffer from detrimental effects associated with the magnetization reversal of a ferromagnetic layer. Eliminating a ferromagnet reduces the energy-delay product by eliminating the energy needed to reverse a ferromagnet and us the intrinsically high switching speed of antiferromagnets (AFM). We study the electrically-controlled boundary magnetization of the AFM magnetoelectric (ME) chromia in thin films using Pt as a sensing layer. We provide evidence that the main contribution to the anomalous Hall effect (AHE)-signal in chromia/heavy metal (HM) devices originates from spin Hall magnetoresistance and not from the proximity induced magnetization in the HM. To accomplish this, we investigate the temperature, magnetic field, and Pt-thickness dependence of the transverse and longitudinal resistivity. Our results promise a pathway to optimize AHE readout, overcoming energy-delay constraints accompanying magnetization reversal in ferromagnets.