US Patent 11417356 Write assist stack to reduce resistance and improve reliability

The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a main pole, a hot seed layer, and a write assist stack disposed between the main pole and the hot seed layer. In one embodiment, the write assist stack comprises a seed layer, a spin torque layer, and a notch layer. One or more of the seed layer and the notch layer have a first cross-track width and the spin torque layer has a second cross-track width less than the first cross track width. In another embodiment, the write assist stack comprises a seed layer, a spin polarization layer, and a notch layer. One or more of the seed layer and the notch layer have a first cross-track width and the spin polarization layer has a second cross-track width less than the first cross track width.