Provided herein is an apparatus, including a first region of a substrate corresponding to a data region in a patterned recording medium; a first set of protrusions etched out of the first region of the substrate, wherein the protrusions of the first set of protrusions are rectangle shaped; a second region of the substrate corresponding to a servo region in a patterned recording medium; and a second set of protrusions etched out of the second region of the substrate, wherein the second set of protrusions includes radial lines etched into the substrate across chevrons etched out of the substrate.

A magnetic recording device includes: a magnetic recording medium containing a plurality of recording layers; a magnetic recording head for conducting magnetic writing of information in the magnetic recording medium; and a magnetic reproducing head for conducting magnetic reading out of the information from the magnetic recording medium; wherein the magnetic recording head includes a high frequency oscillator for magnetically assisting the magnetic writing of the information so as to change a magnetization of at least one of the plurality of recording layers of the magnetic recording medium, thereby recording a plurality of information different from one another in the magnetic recording medium commensurate with a total amount of magnetization of the plurality of recording layers.

The embodiments disclose a method including patterning a template substrate to have different densities using hierarchical block copolymer density patterns in different zones including a first pattern and a second pattern, using a first directed self-assembly to pattern a first zone in the substrate using a first block copolymer material, and using a second directed self-assembly to pattern a second zone in the substrate using a second block copolymer material.

Provided herein is an apparatus, including a first region of a substrate corresponding to a data region in a patterned recording medium; a first set of protrusions etched out of the first region of the substrate, wherein the protrusions of the first set of protrusions are rectangle shaped; a second region of the substrate corresponding to a servo region in a patterned recording medium; and a second set of protrusions etched out of the second region of the substrate, wherein the second set of protrusions includes radial lines etched into the substrate across chevrons etched out of the substrate.

A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic coercivity H.sub.k extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.

A magnetic disk device according to an embodiment includes: a magnetic disk including a plurality of tracks; a magnetic head that performs data reading and data writing on the magnetic disk; a plurality of servo regions that is provided in each of the plurality of tracks, and at least partially includes a first physical pattern, the first physical pattern being a physical pattern after writing of a first data pattern including position information of each of the plurality of tracks; and a controller that controls the magnetic head, wherein the plurality of servo regions includes one of a first servo region including the first physical pattern, and a second servo region including a second physical pattern, the second physical pattern being a physical pattern after writing of a second data pattern different from the first data pattern, for each of the plurality of tracks, and the controller performs determination as to which of the first and second physical patterns a third servo region has, the third servo region being one of a servo region among the plurality of servo regions included in the plurality of tracks.