1. A transformer comprising: a first winding operatively coupled to a first conductive contact layer of a material stack, the material stack also having a variable resistive layer, a fixed resistive layer, and a second conductive contact layer, the variable resistive layer and the fixed resistive layer being positioned between the first and second conductive contact layers; a second winding operatively coupled to the second conductive contact layer, the first and second windings being configured in a differential configuration where a vector sum of a third magnetic field generated by the first and second windings is applied to a third winding such that a current difference between the first and second windings is detected and presented as an output of the third winding; the first and second windings being configured to present opposing magnetic fields relative to each other when a current pulse of the same polarity is applied to a first input and a second input connected to the material stack, and the third winding being configured to generate a proportional output signal resulting from a difference in current distributions in the material stack due to the difference between a first resistive state and a second resistive state of the variable resistive layer resulting in a proportional response in the magnetic fields generated by the first and second windings based on the difference in current between the first and second conductive contact layers.