A magnetic tape device includes: a magnetic tape including a servo pattern on a magnetic layer; and a Tunneling Magnetoresistive (TMR) head as a servo head, in which the center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape is equal to or smaller than 2.0 nm, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and SFD in a longitudinal direction of the magnetic tape calculated by Expression 1: SFD=SFD.sub.25 C.SFD.sub.190 C. is equal to or smaller than 0.50, wherein the SFD.sub.25 C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25 C., and the SFD.sub.190 C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 190 C.

A magnetic tape device includes: a magnetic tape including a servo pattern on a magnetic layer; and a Tunneling Magnetoresistive (TMR) head as a servo head, in which the center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape is equal to or smaller than 2.0 nm, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and SFD in a longitudinal direction of the magnetic tape calculated by Expression 1: SFD=SFD.sub.25 C.SFD.sub.190 C. is equal to or smaller than 0.50, wherein the SFD.sub.25 C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25 C., and the SFD.sub.190 C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 190 C.

Provided is a signal detection method of a staggered two-dimensional bit-patterned media and a recording medium and an apparatus for performing the method. The signal detection method of staggered two-dimensional bit-patterned media includes the down-track detection step, which detects a signal through a horizontal direction (x) path along the down-track, the first cross-track detection step, which detects a signal through a first vertical direction (z.sub.1) path that allows for passing through of a plurality of pixels arranged on a same line along cross-track perpendicular to the down-track and a plurality of pixels arranged in a staggered manner toward the horizontal direction (x) path with respect to the cross-track, and the second cross-track detection step, which detects a signal through a second vertical direction (z.sub.2) path that allows for passing through of a plurality of pixels arranged on a same line along the cross-track and a plurality of pixels arranged in a staggered manner toward an opposite path to the horizontal direction (x) path with respect to the cross-track.

Methods to pattern substrates with dense periodic nanostructures that combine top-down lithographic tools and self-assembling block copolymer materials are provided. According to various embodiments, the methods involve chemically patterning a substrate, depositing a block copolymer film on the chemically patterned imaging layer, and allowing the block copolymer to self-assemble in the presence of the chemically patterned substrate, thereby producing a pattern in the block copolymer film that is improved over the substrate pattern in terms feature size, shape, and uniformity, as well as regular spacing between arrays of features and between the features within each array compared to the substrate pattern. In certain embodiments, the density and total number of pattern features in the block copolymer film is also increased. High density and quality nanoimprint templates and other nanopatterned structures are also provided.

Methods for magnetic recording are provided. The method can include: assembling a plurality of nanoparticles into a pattern on a disc; applying a polymer composition onto the pattern of nanoparticles; curing the polymer composition to form a polymer film on the disc, wherein the plurality of nanoparticles are immobilized in the pattern within the polymer film upon curing; and removing the polymer film containing the plurality of nanoparticles in the pattern. Diffraction gratings are also provided that can include a polymeric film comprising a plurality of nanoparticles immobilized in a pattern, wherein the polymer film defines a curvature.

The invention provides a magnetic recording medium with an excellent signal-to-noise ratio during reading by reducing the noise produced during writing of data onto the magnetic recording medium, and increasing the signal level. The assisted magnetic recording medium according to one embodiment comprising a substrate, a base layer, and a magnetic layer composed mainly of an alloy with an L1.sub.0-type crystal structure, the assisted magnetic recording medium having a pinning layer in contact with the magnetic layer, and the pinning layer including Co or an alloy composed mainly of Co.

Methods are disclosed for increasing areal density in Heat Assisted Magnetic Recording (HAMR) data storage systems by controlling the media layer grain size, grain size distribution, and pitch via templating techniques that are compatible with the high temperature HAMR media deposition. Embodiments include using current HAMR media seed layers as well as additionally introduced interlayers for the templating process. Topographic as well as chemical templating methods are disclosed that may employ nanoimprint technology or nanoparticle self-assembly among other patterning techniques.

A servo sector on a disk is read via first and second readers that both span two or more user data tracks. The servo sector has a crosstrack width that spans the two or more user data tracks. The first reader provides a first signal based on detecting a total longitudinal field of the servo sector. The second reader provides a second signal based on detecting a total perpendicular field of the servo sector. A position error of the first and second readers is detected using. A value of the first signal can be used to detect a position error, detect a track-to-track phase error, and/or detect a Gray code error of a track ID field of the servo sector.

A system according to one embodiment includes a pinned layer; a spacer layer above the pinned layer; a free layer above the spacer layer; a heating device, for heating the free layer to induce a paramagnetic thermal instability in the free layer whereby a magnetization of the free layer randomly switches between different detectable magnetic states upon heating thereof; and a magnetoresistance detection circuit for detecting an instantaneous magnetic state of the free layer.

A system according to one embodiment includes a pinned layer; a spacer layer above the pinned layer; a free layer above the spacer layer; a heating device, for heating the free layer to induce a paramagnetic thermal instability in the free layer whereby a magnetization of the free layer randomly switches between different detectable magnetic states upon heating thereof; and a magnetoresistance detection circuit for detecting an instantaneous magnetic state of the free layer.