1. An apparatus, comprising: a circuit including a magnetic tunnel junction including a storage layer and a sense layer; and a field line configured to generate a magnetic field based on an input signal, wherein the magnetic tunnel junction is configured such that a magnetization direction of the sense layer and a resistance of the magnetic tunnel junction vary based on the magnetic field; wherein the circuit is configured to amplify the input signal to generate an output signal that varies in response to the resistance of the magnetic tunnel junction and wherein the magnetic tunnel junction is included in a plurality of magnetic tunnel junctions included in the circuit, and further comprising a feedback circuit configured to control linearity of amplification of the input signal by adjusting current flow through the field line to set a combined resistance of the plurality of magnetic tunnel junctions.