Observation of asymmetry in anomalous Hall effect measurements of magnetic dots

Anomalous Hall effect (AHE) measurements are performed on magnetic dots that have two separate switching events. The CoPd-Pd-CoNi multilayers are obtained via sputtering and ion milling. Results show that CoPd has a negative AHE coefficient and CoNi a positive AHE coefficient, causing the voltage steps to have opposite sign. The hysteresis loop is shown to be asymmetric and is independent of the DC current direction.