Abstract: A heat-assisted magnetic recording head includes a near-field transducer (NFT). The NFT includes a near-field emitter configured to heat a surface of a magnetic disk, and a heat sink. The heat sink includes at least one of rhodium, copper, tungsten, tantalum, iridium, platinum, ruthenium, nickel, or iron.

Abstract: The present disclosure relates to a recording head that includes a write pole extending to a media-facing surface of the recording head; a near-field transducer extending to a media-facing surface of the recording head; a trailing return pole positioned between the write pole and the trailing edge; and a recessed portion that is recessed relative to the media-facing surface by a distance when no power is applied to the recording head. The trailing return pole is located in the recessed portion. The present disclosure also includes relates methods of making and detecting contact between a recording head and recording medium.

Abstract: Various illustrative aspects are directed to a data storage device comprising data tracks N and N?1, and one or more processing devices, configured to measure signal to noise ratio (SNR) metrics for corresponding sectors of at least one of the data tracks N?1 and N, where the measuring is based at least in part on reading one or more of the data tracks N and N?1 using one or more read offsets, estimate a position of at least one of the data tracks based on measuring the one or more SNR metrics, and reconstruct one or more of risk values for at least a portion of the data track N?1 based on the one or more SNR metrics for the data track N?1, and a position error signal (PES) for at least one of the data tracks N?1 and N based on the corresponding estimated positions.

Abstract: A method for characterizing a magnetic recording tape, according to one approach, includes measuring, using a magnetic head having servo readers of known pitch, a servo band difference at various locations along a length of a magnetic recording tape. The servo band difference measurements and/or derivatives thereof are stored in association with the magnetic recording tape. This procedure creates a characterization of the magnetic recording tape that is useful for assessing aging of the magnetic recording tape, as well as improving subsequent reading and/or writing operations.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head including a read head that reads data from the disk, a write head that writes data to the disk, and an assist element that generates energy to enhance write performance by the write head, and a controller that selects and performs a first recording mode and a second recording mode different from the first recording mode, and selects and performs one of the first recording mode and the second recording mode according to an assist effect of the assist element.

Abstract: A magnetic disk device includes a disk, first and second heads, a motor, and a controller. The disk includes a first surface and a second surface opposite to the first surface. The first head is configured to perform reading and writing with respect to the first surface. The second head is configured to perform reading and writing with respect to the second surface. The motor is configured to move the first and second heads with respect to the first and second surfaces, respectively, along a radial direction of the disk. The controller is configured to alternately activate the first and second heads to perform writing of a plurality of spiral patterns on the first and second surfaces of the disk, respectively, while controlling the motor to move the first and second heads at a predetermined constant speed with respect to the first and second surfaces in the radial direction.

Abstract: According to one embodiment, a magnetic disk device, including a disk, a head to write data to the disk and read data from the disk, a preamplifier to generate a recording current corresponding to data that the head writes to the disk, and a controller to convert a first data pattern in first write data, in accordance with a pattern length of a second data pattern previous to the first data pattern, to a different data pattern including a pseudo polarity inversion that does not cause a polarity inversion when converting the first data pattern to the recording current.

Abstract: Systems and methods are disclosed for phase locking of a clock. In some embodiments, a phase locked clock (PLC) module can phase-lock a write clock to a media written with multiple servo zones of different frequencies. In some implementations, this can be utilized to perform a self-servo write (SSW) of a disc surface within a hard disc drive (HDD). A PLC module can perform a method of writing with a single frequency phase coherently while a read element passes over servo zones with different frequencies. While the PLC module can perform such methods for a SSW process, the methods can also be utilized for other applications that can benefit from writing with a single frequency phase coherently based on servo zones with different frequencies.

Abstract: Example preamplifier circuits, data storage devices, and methods to provide a preamplifier circuit with separate read and write power channels are described. The preamplifier circuit may include a write driver circuit configured to send a write signal to a writer element of a data storage device and a read driver circuit configured to receive a read signal from a reader element of the data storage device. The write driver circuit may receive a write power signal through a write power channel of a bus interface and the read driver circuit may receive a read power signal through a read power channel of the bus interface, where the write power signal and the read power signal are different. In some configurations, the different read and write power signals may be received from a switching regulator on the printed circuit board that mounts other data storage device electronics, such as the drive controller circuit and/or read/write channel circuit.

Abstract: The magnetic tape container includes a core around which a magnetic tape is wound. The magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A maximum value of a deviation of a center position of an average minimum region reference circle of a trajectory of one rotation drawn by the magnetic tape, in a case where the wound magnetic tape is drawn out from the core core is 100 ?m or less for three points of the magnetic tape in a width direction.

Abstract: A tape drive includes a plurality of rollers, a head, a tension sensor, and control circuitry. The rollers are spatially arranged within the tape drive to define a route for tape of a received data cartridge to travel from the received data cartridge to a tape reel. The head includes read elements and write elements configured to read from and write to the tape as tape of the received data cartridge travels along the route. The tension sensor is configured to measure tension of the tape as it travels along the route. The control circuitry is configured to cause a motor to impact the tension to keep the tape within a tension threshold.

Abstract: A data storage device includes at least one data storage disc having at least one data storage surface, and at least one read head configured to communicate with the at least one data storage surface. The data storage device also includes a controller communicatively coupled to the at least one read head. The controller is configured to determine a fly height for the at least one read head over the at least one data storage surface as a function of a read workload associated with the at least one data storage surface or as a function of an ability to satisfy a read request to the at least one data storage surface on a first read attempt.

Abstract: Example systems, data storage devices, and methods to provide long-term spacing compensation for heat assisted magnetic recording are described. The data storage device includes a storage medium with data tracks and a head that can be positioned for reading and writing those tracks. The head includes a laser for heat assisted magnetic recording and a fly height actuator. Based on the operation of the laser, both a short-term fly height compensation parameter and a long-term fly height compensation parameter are determined based on different temperature state models. The operating power of the fly height actuator is determined, at least in part, based on the short-term and long-term height compensation parameters.

Abstract: A heat-assisted magnetic recording head includes a near-field emitter and a middle disk. The near-field emitter includes a peg and an anchor disk. The peg is configured to produce a hot spot on a proximal magnetic disk. The peg is disposed proximal to a media-facing surface of the heat-assisted magnetic recording head. The anchor disk is disposed behind the peg relative to the media-facing surface. The middle disk has a melting temperature of at least 1500 degrees Celsius. The middle disk is disposed in a down-track direction relative to the near-field emitter and is coupled to the anchor disk.

Abstract: A heat-assisted magnetic recording head includes a waveguide and a near-field transducer. The near-field transducer includes a plasmonic disk disposed proximal to the waveguide. The plasmonic disk includes a first plasmonic layer, a second plasmonic layer, and a middle layer. The first plasmonic layer is coupled to the waveguide. The second plasmonic layer is disposed distal to the waveguide relative to the first plasmonic layer. The middle layer is disposed between the first plasmonic layer and the second plasmonic layer.

Abstract: The present embodiments relate to a thermally-assisted magnetic recording (TAMR) head. A magnetic assist current can be applied to the TAMR head to assist in reducing timing jitter as the TAMR head interacts with a magnetic recording material. The TAMR head can include a main write pole including a tip portion and configured to direct a magnetic field for interacting with a magnetic recording medium. The TAMR head can include a laser diode to heat the magnetic recording medium and a dynamic fly height (DFH) heating element for dynamically controlling a height of the main write pole. The heating element can be of a parallel bias circuit that directs a direct current (DC) bias current flow along an electrical path from the magnetic yoke element to the tip portion of the main write pole adjacent to an air bearing surface (ABS).

Abstract: The present disclosure generally relates to using a data timestamp and/or a read counter to prevent data from being re-read and signal that the data has been accessed. The write assist element in the write head can be utilized to degrade the data or an allocated marker after the data has been read. The degradation functions as a read counter to indicate how many times the data has been read. Additionally and/or alternatively, a timestamp can be utilized. The timestamp is updated each time that the data has been accessed. In so doing, it is possible to determine whether data in a data storage device has been accessed.

Abstract: Illustrative aspects are directed to a data storage device comprising one or more disks; an actuator mechanism comprising one or more heads, and configured to position a head proximate to a disk surface; and one or more processing devices. The one or more processing devices are configured to: measure a read quality of a location on the disk surface; modify a refresh frequency for performing refresh writes at the location, based on the read quality at the location; in response to the refresh frequency at the location becoming stabilized, determine an integrated track interference (xTI) per write metric at the location; and, in response to determining that the xTI per write metric at the location is below a threshold for the xTI per write metric, modify an operating parameter of the head at the location to improve a longevity metric.

Abstract: Example read transducers, data storage devices, and methods to provide an angled free layer for generating and decoding multi-level read signals are described. The read transducer includes a free layer having a magnetization bias sensitive to an external magnetic field and the direction of the magnetization bias forms an acute angle relative to a surface of the non-volatile storage medium generating the external magnetic field. The read transducer also includes a pinned layer having a fixed magnetization and a direction of the fixed magnetization forms a right angle with the magnetization bias of the free layer. The read transducer targets a readback location on a track boundary between adjacent tracks and generates a read signal indicative of perpendicular and cross-track fields of the adjacent tracks.

Abstract: According to one embodiment, a magnetic disk device includes a plurality of magnetic disks, a plurality of magnetic heads provided correspondingly to the plurality of magnetic disks and configured to carry out read/write of data from/to the magnetic disks, and a control section configured to control read/write of the magnetic heads. Each of the plurality of magnetic disks includes a first storage section storing therein control information concerning read/write of the magnetic head. The control section switches the first storage section which is a storage destination of first information that is at least a part of the control information from the magnetic disk to another magnetic disk.