Magnetic write head with write-field enhancement structure including a magnetic notch

A data storage device, comprising:

• at least one recording media;
• a write head for writing to the at least one recording media, the write head comprising:
• a main pole,
• a trailing shield,
• a magnetic notch adjacent to either the trailing shield or the main pole,
• a non-magnetic spacer situated between the main pole and the trailing shield,
• a non-magnetic layer situated between the main pole and the trailing shield, and
• a magnetic DC-field-generation (DFG) layer adjacent to the non-magnetic spacer and situated between the non-magnetic spacer and the non-magnetic layer, wherein the magnetic DFG layer is the only magnetic layer between the main pole and the trailing shield that is not adjacent to the main pole or the trailing shield;
• a first conducting line for providing a write current to the main pole;
• a second conducting line for providing a bias current to the magnetic DFG layer;
• and
• signal processing circuitry coupled to the first and second conducting lines and configured to control the write current and the bias current,
• wherein a damping of the magnetic notch is selected such that, in operation, the magnetic notch provides spin-torque to align a DC component of a magnetization of the DFG layer in a direction that is substantially opposite to a gap field direction, and wherein the damping exceeds a threshold damping value.

A data storage device, comprising:

• at least one recording media;
• a write head for writing to the at least one recording media, the write head comprising:
• a main pole,
• a trailing shield,
• a magnetic notch adjacent to either the trailing shield or the main pole,
• a non-magnetic spacer situated between the main pole and the trailing shield,
• a non-magnetic layer situated between the main pole and the trailing shield, and
• a magnetic DC-field-generation (DFG) layer adjacent to the non-magnetic spacer and situated between the non-magnetic spacer and the non-magnetic layer, wherein the magnetic DFG layer is the only magnetic layer between the main pole and the trailing shield that is not adjacent to the main pole or the trailing shield;
• a first conducting line for providing a write current to the main pole;
• a second conducting line for providing a bias current to the magnetic DFG layer;
• and
• signal processing circuitry coupled to the first and second conducting lines and configured to control the write current and the bias current,
• wherein a resistivity of the magnetic notch is selected such that, in operation, the magnetic notch provides spin-torque to align a DC component of a magnetization of the DFG layer in a direction that is substantially opposite to a gap field direction, and wherein the resistivity is less than a threshold resistivity value.