Abstract: Devices having air bearing surfaces (ABS), the devices include a near field transducer (NFT) that includes a disc; a peg, the peg including gold (Au), silver (Ag), copper (Cu), aluminum (Al), rhodium (Rh), iridium (Ir), or combinations thereof; and the peg having a front surface at the air bearing surface of the device, an opposing back surface, a top surface that extends from the front surface to the back surface, two side surfaces that extend from the front surface to the back surface and a bottom surface that extends from the front surface to the back surface; and a protective layer disposed on at least one surface of the peg, the protective layer comprising an oxide of a metal that has a higher oxidation tendency than that of the material of the peg.

Abstract: An apparatus includes a first waveguide core extending along a light-propagation direction and configured to receive light from a light source at a combined transverse electric (TE) mode and a transverse magnetic (TM) mode. A second waveguide core is spaced apart from the first waveguide core and is configured to couple light at a TM mode to the second waveguide core. A near-field transducer (NFT) is disposed at a media-facing surface of a write head, the NFT receiving the light from the first waveguide core or the second waveguide core and heating a magnetic recording medium in response thereto.

Abstract: A compressed format is selected for storage of a matrix based on a computation to be performed using the matrix and architecture of a storage compute device to which the matrix is stored. Data of the matrix is stored on the storage compute device according to the compressed format. The computation is performed using the data via a computation unit that resides within the storage compute device.

Abstract: Amplifiers, preamplifiers, and other circuits may have registers that are assigned to store data corresponding to certain functions. When the data stored in the registers are no longer needed, the registers may be assigned to store data corresponding to other functions, such as signal acquisition. The registers can be logically grouped into a virtual memory bank. The memory bank may store new data to a first register, and move data from the first register to a second register when new data arrives. In some embodiments, these registers and memory control circuit can be implemented within a preamplifier circuit.

Abstract: The system includes a data storage medium comprising cells, an excitation circuit, and an emitter. The cells arranged in a three dimensional space. The excitation circuit excites each cell independently. Exciting a cell changes an optical property of the cell. The emitter emits a first beam onto a first cell during a first excitation period to orient electrical charges within the first cell to a first oriented value and intensity of electric field to a first intensity value. The emitter emits a second beam onto a second cell during a second excitation period to orient electrical charges within the second cell to a second oriented value and intensity of electric field to a second intensity value. The first and second cells maintain the first and the second oriented values and the first and second intensity values after the first and second excitation periods are over, respectively.

Abstract: A method involves determining bit aspect ratios for interlaced tracks written to a magnetic recording medium. The interlaced tracks include top tracks that are written partially overlapping and interlaced with bottom tracks. Isolated test tracks are written at first different bit aspect ratios to determine a top bit aspect ratio that achieves a first target areal density for the isolated test tracks. Interlaced test tracks are written at second different bit aspect ratios to determine a bottom bit aspect ratio that achieves a second target areal density for the interlaced test tracks. Top test tracks of the interlaced test tracks are written at the top bit aspect ratio. The top and bottom bit aspect ratios are selected to subsequently write interlaced tracks on the magnetic recording medium.

Abstract: A magnetic sensor assembly includes first and second shields each comprised of a magnetic material. The first and second shields define a physical shield-to-shield spacing. A sensor stack is disposed between the first and second shields and includes a seed layer adjacent the first shield, a cap layer adjacent the second shield, and a magnetic sensor between the seed layer and the cap layer. At least a portion of the seed layer and/or the cap layer comprises a magnetic material to provide an effective shield-to-shield spacing of the magnetic sensor assembly that is less than the physical shield-to-shield spacing.

Abstract: A data storage device can employ shingled magnetic recording with data tracks oriented in order to optimize operational parameters, such as bit error rate. A data storage device can consist of a plurality of data tracks overlapping in a band on a data storage medium. First, second, and third data tracks of the band can be respectively separated by a uniform first track pitch during testing the band for an operational parameter. The first track pitch may then be adjusted to provide at least two different adjusted track pitches with each track pitch measured between longitudinal centerlines of adjacent data tracks of the band.

Abstract: A slider configured for heat-assisted magnetic recording comprises a magnetic writer, a near-field transducer, and an optical waveguide coupling the near-field transducer to a light source. The writer is situated proximate the near-field transducer at an air bearing surface of the slider and comprises a first return pole, a second return pole, and a write pole situated between and spaced apart from the first return pole and the second return pole. A structural element is situated at or near the air bearing surface between the write pole and one of the first and second return poles. The structural element comprises a cavity. A thermal sensor is disposed in the cavity. The thermal sensor is configured for sensing contact between the slider and a magnetic recording medium, asperities of the medium, and output optical power of the light source.

Abstract: An apparatus includes an apparatus comprising a slider. The slider comprises a substrate comprising a media-facing surface, a first side surface perpendicular to the media-facing surface, and a second side surface opposite the first side surface. A heat sink layer is formed proximate to and thermally coupled to the first side surface of the substrate. A write transducer comprises a waveguide core that at least partially extends from the top surface to the media-facing surface. The waveguide core is formed proximate to and thermally coupled to the heat sink layer. A read transducer is formed proximate to the write transducer such that the read transducer is closer to a trailing edge of the slider than the write transducer.

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: Methods that include depositing a first layer over the entire surface of a structure, the structure having a magnetic reader and a magnetic writer, wherein the magnetic reader and the magnetic writer are positioned adjacent to each other on a substrate and the magnetic writer includes a near field transducer (NFT); depositing a second layer over the entire surface of the first layer; depositing a photoresist material layer over the entire surface of the second layer, the photoresist material layer having a bottom surface in contact with the second layer and an opposing top surface; exposing the photoresist material layer to radiation through the bottom surface of the photoresist material layer via the NFT to form a first exposed region; and exposing the photoresist material layer to radiation through the top surface of the photoresist material layer to form a second exposed region.

Abstract: Power-backup capabilities are provided by implementing a variety of different methods, systems and devices. According to one such implementation, an energy storage device such as a capacitive storage circuit is powered relative to the powering of one or more additional circuits from a common power supply to limit the draw upon the power supply. Certain applications involve delaying or otherwise modifying the powering of the capacitive storage circuit, which may involve an initial startup of the capacitive storage circuit.

Abstract: A printed circuit board assembly includes a printed circuit board having a plurality of signal lanes. The PCBA also includes at least one application-specific integrated circuit operatively mounted to the printed circuit board and connected with the plurality of signal lanes. The PCBA includes a first configuration element operatively mounted to the printed circuit board in a first orientation and at a first location and having a first bridging element for providing an electrical connection between at least a first pair of signal lanes selected from the plurality of signal lanes. The first configuration element also includes a second bridging element so that if the first configuration element were operatively mounted to the printed circuit board in a different, second orientation relative to the printed circuit board, the second bridging element would provide an electrical connection between at least a second pair of signal lanes.

Abstract: Systems and methods are disclosed for open block refresh management. In certain embodiments, an apparatus may comprise a circuit configured to monitor an amount of time a block of a solid-state memory remains in an open state where the block has not been fully filled with data, and in response to reaching an open block time limit, compare an amount of the block already written with data against a threshold amount. When less than a threshold amount of the block has been written with data, the circuit may refresh data from a last N pages from the block by writing the data to a new location, N being a number of pages less than all pages in the block. When more than the threshold amount of the block has been written with data, the circuit may fill a remaining unwritten amount of the block with dummy data.

Abstract: In a disk drive apparatus, a first time period is determined, during which a first head driven by a first actuator will be performing a first disk access operation. A second time period is determined, during which a second head driven by a second actuator will be performing a second disk access operation. The first and second actuators are independently movable such that the first and second disk access operations are capable of being performed in parallel. If it is determined that the second disk access operation will impact servo control of the first disk access operation, at least one of the first and second disk access operations is changed to reduce the impact to the servo control of the first disk access operation.

Abstract: A method for method for resolving a cable mismatch by a target device is provided. The method includes determining that all PHYs in a receptacle are currently inactive, a PHY in the receptacle became active, and determining if there is a mismatch between a cable type and a stored cable configuration. If there is a mismatch between the cable type and the stored cable configuration, the method further includes disabling all other PHY groups in the receptacle that do not include the PHY that became active and notifying a user that a cable mismatch corresponding to the receptacle has occurred. If there is not a mismatch between the cable type and the stored cable configuration, then the method includes re-enabling PHYs in the receptacle, if any PHYs are disabled, and notifying a user that a cable mismatch corresponding to the receptacle has been corrected.

Abstract: A data storage device includes first and second controllers that independently and simultaneously process data from a recording medium. The first and second controllers each have respective first and second buffer managers coupled to respective first and second buffer memories. The first and second buffer managers are coupled to each other via an inter-controller data bus. The first controller is configured to receive a contiguous memory request for a block data transfer client of the first controller. A first part of the request is fulfilled from the first buffer memory via the first buffer manager, and a second part of the request is fulfilled from the second buffer memory via the second buffer manager communicating with the first buffer manager via the inter-controller data bus.

Abstract: In a device with first and second heads, the second head is held at a radial location over one or more disks via a second actuator that moves the second head. A position error of the second head is read while performing a seek with a first actuator, the first actuator moving the first head over the one or more disks. A mechanical transfer function is determined between the first actuator and the second actuator based on the position error of the second head. The mechanical transfer function is used to provide compensation for the second head via the second actuator in response to subsequent seek of the first actuator.

Abstract: A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.