Abstract: A heat-assisted magnetic recording (HAMR) device is configured to write regions of neutral polarity on a magnetic media during a same pass of the recording head in which other regions are written of positive polarity and negative polarity. The various disclosed write techniques may facilitate creation of “zero state” (substantially net zero polarity) transition zones between each pair of data bits of opposite polarity and/or may facilitate the encoding of three different logical states (e.g., 1, 0, and ?1) on the media.

Abstract: A heat-assisted magnetic recording (HAMR) device is configured to write regions of neutral polarity on a magnetic media during a same pass of the recording head in which other regions are written of positive polarity and negative polarity. The various disclosed write techniques may facilitate creation of “zero state” (substantially net zero polarity) transition zones between each pair of data bits of opposite polarity and/or may facilitate the encoding of three different logical states (e.g., 1, 0, and ?1) on the media.

Abstract: A heat-assisted magnetic recording (HAMR) device is configured to write regions of neutral polarity on a magnetic media during a same pass of the recording head in which other regions are written of positive polarity and negative polarity. The various disclosed write techniques may facilitate creation of “zero state” (substantially net zero polarity) transition zones between each pair of data bits of opposite polarity and/or may facilitate the encoding of three different logical states (e.g., 1, 0, and ?1) on the media.

Abstract: Apparatus and methods to identify nucleotides of a DNA strand. The method includes exposing the DNA strand to a first dye or peptide, attaching the first dye or peptide to a first type of nucleotide (A,T,C,G) of the DNA strand, the first dye or peptide changing a conductance of the first type of nucleotide to which the first dye or peptide is attached, and measuring a tunneling current signal for all nucleotides of the DNA strand, the changed conductance of the first type of nucleotide providing amplified tunneling current discrimination of the nucleotides of the DNA strand.

Abstract: A heat-assisted magnetic recording device includes a granular magnetic recording layer and a thermal absorption layer formed on top of the magnetic recording layer. The thermal absorption layer is patterned to include rows extending in a cross-track direction of the magnetic media, each adjacent pair of the rows being separated from one another by an insulating material.

Abstract: A method of forming a patterned media includes constraining growth of magnetic grains in a down-track direction without constraining the growth in a radial direction to cause the magnetic grains to align in rows extending in the radial direction. The patterned media may allow for data track radial width to be defined independent of grain size.

Abstract: Apparatus and methods to identify nucleotides of a DNA strand. The method includes exposing the DNA strand to a first dye or peptide, attaching the first dye or peptide to a first type of nucleotide (A,T,C,G) of the DNA strand, the first dye or peptide changing a conductance of the first type of nucleotide to which the first dye or peptide is attached, and measuring a tunneling current signal for all nucleotides of the DNA strand, the changed conductance of the first type of nucleotide providing amplified tunneling current discrimination of the nucleotides of the DNA strand.

Abstract: Apparatus and methods to identify nucleotides of a DNA strand. The method includes exposing the DNA strand to a first dye or peptide, attaching the first dye or peptide to a first type of nucleotide (A,T,C,G) of the DNA strand, the first dye or peptide changing a conductance of the first type of nucleotide to which the first dye or peptide is attached, and measuring a tunneling current signal for all nucleotides of the DNA strand, the changed conductance of the first type of nucleotide providing amplified tunneling current discrimination of the nucleotides of the DNA strand.

Abstract: Apparatus and methods to identify nucleotides of a DNA strand. The method includes exposing the DNA strand to a first dye or peptide, attaching the first dye or peptide to a first type of nucleotide (A,T,C,G) of the DNA strand, the first dye or peptide changing a conductance of the first type of nucleotide to which the first dye or peptide is attached, and measuring a tunneling current signal for all nucleotides of the DNA strand, the changed conductance of the first type of nucleotide providing amplified tunneling current discrimination of the nucleotides of the DNA strand.

Abstract: A three dimensional magnetic recording media can consist of a coupling layer disposed between first and second vertically stacked recording layers. The coupling layer can provide exchange or antiferromagnetic coupling and allow the respective recording layers to be individually heat selected to different first and second coupling strengths through application of heat from a heat source.

Abstract: A three dimensional magnetic recording medium can consist of a first recording layer vertically stacked with a second recording layer. The first stacked recording layer may be tuned with at least one discrete track physically separating multiple data tracks in the first recording layer or tuned by being configured as a bit patterned media.

Abstract: A three-dimensional magnetic recording media can consist of a single recording layer configured with three or more separate magnetization levels. A first magnetization level can be written to a selected region of said recording layer by applying a first write field to the grains of said region to form a “spin-up” magnetization in the grains of said region. A second magnetization level can be written by applying a second opposite write field to selected grains of said region to form a “spin-down” magnetization. At least a third intermediate magnetization level can be written by applying a weaker or alternating write field to grains of said region to form an intermediate magnetization comprising a mixture of spin-up and spin-down grains. By such method, said region may comprise a data bit capable of storing 3 or more units of information corresponding to the number of separate magnetization levels employed.

Abstract: A three dimensional magnetic recording media can consist of a coupling layer disposed between first and second vertically stacked recording layers. The coupling layer can provide exchange or antiferromagnetic coupling and allow the respective recording layers to be individually heat selected to different first and second coupling strengths through application of heat from a heat source.

Abstract: A system includes a memory, a processor, an encoder, a head, and a decoder. The memory stores information. The processor processes information and controls operation of other components. The encoder encodes a first portion and a second portion of a servo track to form a first and second encoded values. The second code has a run length associated therewith. The first and second encoded values result in a Gray code. Each bit of the Gray code remains constant for at least a number of tracks corresponding to the run length. The head is configured to write the first and the second encoded values onto a media, and is configured to read the first and the second encoded values from the media. The decoder decodes the first encoded value and the second encoded value. The processor determines a servo track address from the decoded first value and the decoded second value.

Abstract: A data signal comprising an even component and an odd component with differing amplitudes is received at a main automatic gain controller (AGC). The even component is adjusted by a first interleaved AGC and the odd component is adjusted by a second interleaved AGC such that even and odd component amplitudes are substantially equal. Amplitude adjusted even and odd components are recombined to define a data signal with components having substantially equal amplitudes. The even and odd components can be generated by a read transducer moving relative to a magnetic storage medium comprising tracks defined by discrete and spaced-apart recording bits arranged in an interspersed pattern. A read channel separates the data signal into even and odd samples such that a gain can be independently adjusted for each of the even and odd samples to compensate for asymmetry between the even and odd samples.

Abstract: A data signal comprising an even component and an odd component with differing amplitudes is received at a main automatic gain controller (AGC). The even component is adjusted by a first interleaved AGC and the odd component is adjusted by a second interleaved AGC such that even and odd component amplitudes are substantially equal. Amplitude adjusted even and odd components are recombined to define a data signal with components having substantially equal amplitudes. The even and odd components can be generated by a read transducer moving relative to a magnetic storage medium comprising tracks defined by discrete and spaced-apart recording bits arranged in an interspersed pattern. A read channel separates the data signal into even and odd samples such that a gain can be independently adjusted for each of the even and odd samples to compensate for asymmetry between the even and odd samples.

Abstract: A hard disk drive for a computer system including a head disk assembly with a disk platter of approximately one-and-eight-tenths-inch in diameter capable of storing more than forty megabytes. In an embodiment, data tracks on each data surface of the platter are spaced at approximately 2,558 tracks per inch and each data track has approximately 36,000 flux changes per inch. An actuator positions a pair of read/write heads on each platter surface using a voice coil motor to position the heads over a cylinder. A magnetic actuator latch attaches to another magnet on the actuator and locks the heads in a parked position at the innermost diameter of the platter. A spindle motor rotates the platter at approximately 5,400 revolutions per minute. A base plate, with a gasketed surface and a raised lip, hermetically seals with a cover to the base plate such that the platter, the actuator, the actuator latch, and the spindle motor are all contained within. The cover carries a breather filter and recirculating air filter.