A magnetoresistive Wheatstone-bridge structure includes a magnetoresistive ring structure. The magnetoresistive ring structure includes a first magnetic layer comprising a ferromagnetic material. A second magnetic layer also includes a ferromagnetic material. A non-magnetic spacer is positioned between the first magnetic layer and the second magnetic layer. A vacant open region is positioned in the center region of the magnetoresistive ring structure. A plurality of magnetic states can exist in either the first magnetic layer or second magnetic layer. Furthermore, the magnetoresistive Wheatstone-bridge structure includes a plurality of voltage and current contacts arranged symmetrically upon the magnetoresistive ring structure. The magnetic state of the ring is detected by measuring its resistance.