This creates an asymmetric electric field perpendicular to the current, which depends on the magnetization state of the sensor. Exactly controlling the magnetization state is the key to the operation of the planar Hall sensor. From fabrication the magnetization is confined to one certain direction in zero applied field, and the application of a field perpendicular to this direction changes the magnetization state in such a way that the electronic readout is linear with respect to the magnitude of the applied field.
This process generates an uneven electric field at right angles to the current flow, which is influenced by the magnetic orientation of the sensor. The accurate control of this magnetic state is essential for the functioning of the planar Hall sensor. Through fabrication, the magnetization is fixed in a single direction when no external field is applied, and introducing a perpendicular field causes the magnetization to shift in response to the applied field, resulting in a linear electronic output proportional to the field strength.