Tuning of a single-MTJ two-axis magnetometer: application of the Stoner-Wohlfarth model

Recently, we demonstrated that, by driving a single magnetic tunnel junction (MTJ) with two alternative magnetic fields, one can measure the two components in the junction plane of an external magnetic field. The first component is measured by using the fluxgate principle while the second one is measured by taking advantage of the switching fields reduction induced by the hard axis field as predicted by the Stoner-Wohlfarth model. By tuning the amplitude of both driving fields, the responses along each axis can be independently adjusted. Although the phenomena that serve for the measurement along the easy axis and the hard axis are different, the effect on the responses is similar in both directions: the sensitivity can be increased (respectively, decreased) while the measurement range is decreased (respectively, increased). Finally, any compromise can be chosen in order to fit the requirements of the application.