Aspects of the present disclosure generally relate to magnetic recording heads of magnetic recording devices. A read head includes a first reader, an insulating separation layer, and a second reader disposed above the insulating separation layer. The second reader includes a magnetic seed layer and a cap layer. The second reader includes a first upper free layer disposed between the magnetic seed layer and the cap layer, and a second upper free layer disposed between the first upper free layer and the cap layer. The second reader includes a barrier layer. In one implementation the second reader includes an antiferromagnetic (AFM) layer disposed between the magnetic seed layer and the insulating separation layer to pin the magnetic seed layer.

A two-dimensional magnetic recording (TDMR) disk drive has a gas-bearing slider that includes first and second sensors with a first cross-track spacing electrically coupled to a first magnetic shield, and third and fourth sensors with a different cross-track spacing electrically coupled to a second magnetic shield. The different spacings results in the first and third sensors and the second and fourth sensors having a cross-track spacing to accommodate for the effect of head skew. Each sensor is connected to an associated amplifier by a suspension trace and a common trace connected to its associated shield. Switching circuitry selects either the first and third amplifiers or the second and fourth amplifiers as the active pair depending on the radial location where the data is to be read. Thus the appropriate pair of sensors are aligned with the data tracks despite the presence of high head skew.

An apparatus that includes a read sensor having a bearing surface and first and second free layers that are separated by an intermediate structure. The first FL includes multiple segments, with each segment having a width at the bearing surface. A sum of the widths of different ones of the multiple segments is a first width of the first FL. The second FL is unsegmented and has a second width at the bearing surface that is different from the first width of the first FL. The read sensor also includes a first terminal connected to a first one of the multiple segments of the first FL, and a second terminal connected to a second one of the multiple segments of the first FL. A third terminal is connected to the second FL. Control circuitry applies a bias current from either the first or second terminal to the third terminal.

A magnetic read apparatus includes a first sensor, a shield layer, an insulating layer, a shield structure and a second sensor. The shield layer is between the first sensor and the insulating layer. The shield structure is in the down track direction from the insulating layer. The shield structure includes a magnetic seed structure, a shield pinning structure and a shield reference structure. The magnetic seed structure adjoins the shield pinning structure. The shield pinning structure is between the shield reference structure and the magnetic seed structure. The second sensor includes a free layer and a nonmagnetic spacer layer between the shield reference structure and the free layer. The shield reference structure is between the shield pinning structure and the nonmagnetic spacer layer. The shield pinning structure includes a pinned magnetic moment. The shield reference structure includes another magnetic moment weakly coupled with the pinned magnetic moment.

Apparatuses and methods for providing thin shields in a multiple sensor array are provided. One such apparatus is a magnetic read transducer including a first read sensor, a second read sensor, and a shield assembly positioned between the first read sensor and the second read sensor at an air bearing surface (ABS) of the magnetic read transducer, the shield assembly including a first shield layer assembly having a first footprint with a first area, and a second shield layer assembly having a second footprint with a second area, where the second area is greater than the first area.

A system according to one embodiment includes a magnetic head having a plurality of sensors arranged to simultaneously read at least three immediately adjacent data tracks on a magnetic medium, wherein none of the sensors share more than one lead with any other of the sensors. Such embodiment may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., hard disk) over the magnetic head, and a controller electrically coupled to the magnetic head.

A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.

The present disclosure generally relates to a read head assembly having a dual free layer (DFL) structure disposed between a first shield and a second shield at a media facing surface. The read head assembly further comprises a rear hard bias (RHB) structure disposed adjacent to the DFL structure recessed from the media facing surface, where an insulation layer separates the RHB structure from the DFL structure. The insulation layer is disposed perpendicularly between the first shield and the second shield. The DFL structure comprises a first free layer and a second free layer having equal stripe heights from the media facing surface to the insulation layer. The RHB structure comprises a seed layer, a bulk layer, and a capping layer. The capping layer and the insulation layer prevent the bulk layer from contacting the second shield.

The present disclosure generally relates to a read head assembly having a dual free layer (DFL) structure disposed between a first shield and a second shield at a media facing surface. The read head assembly further comprises a rear hard bias (RHB) structure disposed adjacent to the DFL structure recessed from the media facing surface, where an insulation layer separates the RHB structure from the DFL structure. The insulation layer is disposed perpendicularly between the first shield and the second shield. The DFL structure comprises a first free layer and a second free layer having equal stripe heights from the media facing surface to the insulation layer. The RHB structure comprises a seed layer, a bulk layer, and a capping layer. The capping layer and the insulation layer prevent the bulk layer from contacting the second shield.

A bottom shield in a read head is modified by including a non-magnetic decoupling layer and second magnetic layer on a conventional first magnetic layer. The second magnetic layer has a magnetization that is not exchange coupled to the first magnetic layer, and a domain structure that is not directly affected by stray fields due to domain wall motion in the first magnetic layer. Accordingly, the modified bottom shield reduces shield related noise on the reader and will provide improved signal to noise (SNR) ratio and better reader stability. The second magnetic layer may be further stabilized with one or both of an antiferromagnetic coupling scheme, and insertion of an antiferromagnetic pinning layer. In dual readers, the modified bottom shield is used in either the bottom or top reader although in the latter, first magnetic layer thickness is reduced to maintain reader-to-reader spacing and acceptable bit error rate (BER).