Abstract: A slider of a heat-assisted magnetic recording head comprises an air bearing surface and an optical waveguide configured to receive light from a laser source. The slider comprises a plurality of electrical bond pads including a first bond pad and a second bond pad. A first resistive sensor is configured to sense for spacing changes and contact between the slider and a magnetic recording medium at or near a first close point of the slider. A second resistive sensor is configured to sense for spacing changes and contact between the slider and the medium at or near a second close point of the slider. A bolometer is situated at a location within the slider that receives at least some of the light communicated along the optical waveguide. The first resistive sensor, the second resistive sensor, and the bolometer are coupled together and between the first and second bond pads.

Abstract: Devices having air bearing surfaces (ABS), the devices including a near field transducer (NFT) that includes a disc configured to convert photons incident thereon into plasmons; and a peg configured to couple plasmons coupled from the disc into an adjacent magnetic storage medium, wherein at least one of a portion of the peg, a portion of the disc, or a portion of both the peg and the disc include a multilayer structure including at least two layers including at least one layer of a first material and at least one layer of a second material, wherein the first material and the second material are not the same and wherein the first and the second materials independently include aluminum (Al), antimony (Sb), bismuth (Bi), boron (B), barium (Ba), calcium (Ca), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), erbium (Er), gadolinium (Gd), gallium (Ga), germanium (Ge), gold (Au), hafnium (Hf), indium (In), iridium (Ir), iron (Fe), lanthanum (La), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), ni

Abstract: Zones of a magnetic recording medium are allocated as a respective plurality of distributed media caches arranged in in a predetermined order. For each of a plurality of caching events, cache data is written to one or more of the distributed media caches. A next of the media caches in the predetermined order is selected for the next caching event if the selected caches are not a last in the predetermined order. Otherwise a first media cache is selected in the predetermined order.

Abstract: Apparatus and method for managing metadata in a data storage device. In some embodiments, a metadata object has entries that describe data sets stored in a non-volatile write cache. During an archival (persistence) operation, the metadata object is divided into portions, and the portions are copied in turn to a non-volatile memory at a rate that maintains a measured latency within a predetermined threshold. A journal is formed of time-ordered entries that describe changes to the metadata object after the copying of the associated portions to the non-volatile memory. The journal is subsequently stored to the non-volatile memory, and may be subsequently combined with the previously stored portions to recreate the metadata object in a local memory. The measured performance latency may be related to a specified customer command completion time (CCT) for host commands.

Abstract: A method involves depositing a near-field transducer on a substrate of a slider. The near-field transducer comprises a plate-like enlarged portion and a peg portion. A first hard stop extending from the near field transducer and an air bearing surface is formed. A heat sink is formed on the enlarged portion and the first hard stop. A dielectric material is deposited over the near-field transducer and the heat sink. A second hard stop is deposited on the dielectric material away from the air bearing surface. The second hard stop comprises a recess corresponding in size and location to the heat sink. The method involves milling at an oblique angle to the substrate between the first hard stop and second hard stop to cut through the heat sink at the angle. The recess of the second hard stop increases a milling rate over the heat sink compared to a second milling rate of the dielectric away from the heat sink.

Abstract: A method includes depositing a plurality of layers over a substrate. The layers include read sensor layers and an electrically conductive layer substantially coplanar with the read sensor layers and substantially surrounding the read sensor layers. The electrically conductive layer is in contact with at least one of the read sensor layers. The electrically conductive layer provides an electrical path between the at least one of the read sensor layers and ground. The method further includes forming an isolation structure around the read sensor layers by removing a portion of the electrically conductive layer substantially surrounding the read sensor layers. The isolation structure is substantially coplanar with the read sensor layers and substantially surrounds the read sensor layers. The isolation structure breaks the electrical path between the at least one of the read sensor layers and the ground.

Abstract: Exemplary systems, apparatus, and methods may write data to data blocks defining health levels corresponding to the quality-of-service levels of the data. Further, when health levels of the data blocks change over time, the data may be moved in an attempt to maintain the data in data blocks defining health levels that correspond to the quality-of-service levels of the data.

Abstract: Technologies are described herein for implementing a space-efficient internal energy storage apparatus in a data storage device or other electronic device have a metallic or otherwise electrically-conductive housing or case structure. The energy storage apparatus comprises an interior surface of the metallic housing, a conductive layer disposed parallel to the interior surface of the metallic housing, and a separator disposed between the interior surface and the conductive layer. The metallic housing is configured to act as a first electrode of the energy storage apparatus and the conductive layer is configured to act as an opposing electrode to the first electrode.

Abstract: A data management system includes a chassis metalwork that is electrically conductive. The chassis metalwork is electrically coupled to the power supply to form a return power path. The return power path may include a sub-chassis frame and a drawer frame. The return power path may also include uninsulated return power cables. The return power cables may be maintained in a cable chain along with outgoing power cables and data cables. The return power cables may be coupled to the drawer frame and the sub-chassis frame.

Abstract: Systems and methods may include a motor and an output shaft apparatus. The output shaft apparatus may be configured to position a manufacturing component using the motor. The output shaft apparatus may move linearly along a longitudinal axis and/or rotationally about the longitudinal axis. The system may also include an engagement apparatus coupling the motor to the output shaft apparatus. The engagement apparatus may be configured in a linear configuration for linearly moving the output shaft apparatus or a rotational configuration for rotationally moving the output shaft apparatus.

Abstract: Devices that include a near field transducer (NFT), the NFT having a disc and a peg, and the peg having five surfaces thereof; and at least one adhesion layer positioned on at least one of the five surfaces of the peg, the adhesion layer including one or more of the following: yttrium (Y), tin (Sn), iron (Fe), copper (Cu), carbon (C), holmium (Ho), gallium (Ga), silver (Ag), ytterbium (Yb), chromium (Cr), tantalum (Ta), iridium (Ir), zirconium (Zr), yttrium (Y), scandium (Sc), cobalt (Co), silicon (Si), nickel (Ni), molybdenum (Mo), niobium (Nb), palladium (Pd), titanium (Ti), rhenium (Re), osmium (Os), platinum (Pt), aluminum (Al), ruthenium (Ru), rhodium (Rh), vanadium (V), germanium (Ge), tin (Sn), magnesium (Mg), iron (Fe), copper (Cu), tungsten (W), hafnium (Hf), carbon (C), boron (B), holmium (Ho), antimony (Sb), gallium (Ga), manganese (Mn), silver (Ag), indium (In), bismuth (Bi), zinc (Zn), ytterbium (Yb), and combinations thereof.

Abstract: A method for scanning for flaws on a magnetic recording medium is disclosed. The magnetic recording medium has a first set of nonconsecutive data tracks and a second set of nonconsecutive data tracks. The method includes writing a test pattern to only the first set of nonconsecutive data tracks of the magnetic recording medium, reading of the test pattern written to the first set of nonconsecutive data tracks, and identifying flaws within the first set of nonconsecutive data tracks and the second set of nonconsecutive data tracks based on the reading the test pattern.

Abstract: A fabrication method that includes cryogenically cooling a multi-layered structure, which includes a barrier layer, in a multi-purpose chamber having a single enclosure around at least one sputtering target and a substrate support. The method also includes depositing a ferromagnetic layer over the barrier layer of the cryogenically cooled multi-layered structure in the single enclosure when the multi-layered structure is supported on the substrate support.

Abstract: Data is written to data sectors of a heat-assisted magnetic recording (HAMR) medium using a laser of a HAMR head supplied with a sum of an operational current and a threshold current. A service current is supplied to the laser when the head is over servo sectors of the medium, such that a temperature of the medium at the servo sectors is greater than or equal to a temperature of the head when over the servo sectors.

Abstract: A recording head includes a magnetic write transducer proximate a near-field transducer. The magnetic write transduce includes a yoke extending in a direction normal to a media-facing surface and a having an edge facing and recessed from the media-facing surface. A write pole extends beyond the first end of the yoke towards the media-facing surface and overlaps a first surface of the yoke that faces the near-field transducer. The write pole has a stepped edge facing away from the media-facing surface. Two or more coil turns are stacked relative to one another in a down-track direction. The two or more coils face a second surface of the yoke that is opposed to the first surface.

Abstract: Gain values used by a variable gain amplifier (VGA) to read servo marks of a heat-assisted recording medium are measured. Sector-specific, repeatable gain values that indicate an expected VGA gain at a desired clearance are determined based on the measured gain values. The sector-specific, repeatable gain values are used as input to a closed-loop clearance controller together with measured values of servo VGA gain while writing data to the recording medium.

Abstract: In certain embodiments, an apparatus may comprise a first output driver connected to a first output via a first trace and a second output driver connected to a second output via a second trace. The first output driver may be configured to output a first drive signal to the first output to drive the first output and the first drive signal may cause first induced noise in the second trace. Further, the second output driver may be configured to output a second drive signal based on the first drive signal where the second drive signal may reduce the magnitude of the first induced noise at the second output.

Abstract: Apparatus and method for proactively cleaning a data storage surface subjected to a mechanical disturbance. In some embodiments, data access commands are serviced by a data storage device to transfer user data between a host device and a rotatable data recording surface using a radially moveable data transducer. A media cleaning operation is scheduled and performed in response to the detection of a mechanical disturbance event externally applied to the data storage device. The media cleaning operation involves sweeping the data transducer across the data recording surface from a first radius to a second radius over a selected time duration. The entirety of the data recording surface is swept if sufficient time is available between pending commands to maintain a desired host data transfer rate. Otherwise, a partial cleaning operation is scheduled in which portions of the recording surface are successively cleaned between the servicing of the pending commands.

Abstract: Apparatus and method for enacting data security in a data storage device, such as by protecting against a differential power analysis (DPA) attack. In some embodiments, a dithered clock signal is generated having a succession of clock pulse segments. Each of the clock pulse segments has a different respective frequency selected in response to a first random number and a different overall duration selected in response to a second random number. The different segment frequencies are selected by supplying the first random number to a lookup table, and the different segment durations are obtained by initializing a timer circuit using the second random number. The dithered clock signal is used to clock a programmable processor during execution of a cryptographic function.

Abstract: Electronic devices may have several power supplies. Current from the power supplies may be provided to multiple loads, such as motors, processors, or other devices. When a current demand of one or more of the loads increases, current from the power supplies may be provided to meet the increased current demands of the one or more loads. To determine how much current can be provided to the loads from the power supplies, output currents of the power supplies can be determined, and a feedback voltage can be generated based on the output currents. The feedback voltage can be compared against hysteretic voltages to determine how much current may be transferred from the power supplies to the loads to compensate for the current demands of the loads.