Abstract: The present disclosure generally relates to a Wheatstone bridge that has four resistors. Each resistor includes a plurality of TMR structures. Two resistors have identical TMR structures. The remaining two resistors also have identical TMR structures, though the TMR structures are different from the other two resistors. Additionally, the two resistors that have identical TMR structures each have an additional non-TMR resistor as compared to the remaining two resistors that have identical TMR structures. Therefore, the working bias field for the Wheatstone bridge is non-zero.

Abstract: A tunneling magnetoresistance (TMR) sensor device is disclosed that includes four or more TMR resistors. The TMR sensor device comprises a first TMR resistor comprising a first TMR film, a second TMR resistor comprising a second TMR film different than the first TMR film, a third TMR resistor comprising the second TMR film, and a fourth TMR resistor comprising the first TMR film. The first, second, third, and fourth TMR resistors are disposed in the same plane. The first TMR film comprises a synthetic anti-ferromagnetic pinned layer having a magnetization direction of the reference layer orthogonal to a free layer. The second TMR film comprises a double synthetic anti-ferromagnetic pinned layer having a magnetization direction of the reference layer orthogonal to the magnetization of a free layer, but opposite to the magnetization direction of the reference layer of the first TMR film.

Abstract: A tunneling magnetoresistance (TMR) sensor device is disclosed that includes one or more TMR resistors. The TMR sensor device comprises a first TMR resistor comprising a first TMR film, a second TMR resistor comprising a second TMR film different than the first TMR film, a third TMR resistor comprising the second TMR film, and a fourth TMR resistor comprising the first TMR film. The first and fourth TMR resistors are disposed in a first plane while the second and third TMR resistors are disposed in a second plane different than the first plane. The first TMR film comprises a synthetic anti-ferromagnetic pinned layer having a magnetization direction of a reference layer orthogonal to a magnetization direction a free layer. The second TMR film comprises a double synthetic anti-ferromagnetic pinned layer having a magnetization direction of a reference layer orthogonal to a magnetization direction of a free layer.

Abstract: The present disclosure generally relates to a Wheatstone bridge array that has four resistors. Each resistor includes a plurality of TMR structures. Two resistors have identical TMR structures. The remaining two resistors also have identical TMR structures, though the TMR structures are different from the other two resistors. Additionally, the two resistors that have identical TMR structures have a different resistance area as compared to the remaining two resistors that have identical TMR structures. Therefore, the working bias field for the Wheatstone bridge array is non-zero.

Abstract: Embodiments of the present disclosure generally relate to a sensor of magnetic tunnel junctions (MTJs) with shape anisotropy. In one embodiment, a tunnel magnetoresistive (TMR) based magnetic sensor in a Wheatstone configuration includes at least one magnetic tunnel junctions (MTJ). The MTJ includes a free layer having a first edge and a second edge. The free layer has a thickness of about 100 ? or more. The free layer has a width and a height with a width-to-height aspect ratio of about 4:1 or more. The MTJ has a first hard bias element positioned proximate the first edge of the free layer and a second hard bias element positioned proximate the second edge of the free layer.

Abstract: Disclosed herein are magnetic recording devices and methods of using them. A magnetic recording device comprises a main pole extending to an air-bearing surface (ABS), a trailing shield extending to the ABS, a write-field-enhancing structure disposed between and coupled to the main pole and the trailing shield at the ABS, a write coil configured to magnetize the main pole, a write current control circuit coupled to the write coil and configured to apply a write current to the write coil, wherein the write current comprises a write pulse, and a bias current control circuit coupled to the write-field-enhancing structure and configured to apply a bias current to the write-field-enhancing structure, wherein the bias current comprises a driving pulse offset in time from the write pulse by a delay, wherein the delay substantially coincides with an expected magnetization switch-time lag of a free layer of the write-field-enhancing structure.

Abstract: A hybrid read head structure for two-dimensional magnetic recording (TDMR) in a disk drive has two stacked current-perpendicular-to-the plane magnetoresistive (CPP-MR) read heads or sensors substantially aligned with one another in the along-the track direction to enable both sensors to read data from the same data track. The structure is a hybrid structure formed on the disk drive slider with the lower sensor being a dual free layer (DFL) or scissoring type of CPP-MR sensor and the upper sensor being a single free layer (SFL) type of CPP-MR sensor.

Abstract: Magnetic sensors using spin Hall effect and methods for fabricating same are provided. One such magnetic sensor includes a spin Hall layer including an electrically conductive, non-magnetic material, a magnetic free layer adjacent to the spin Hall layer, a pair of push terminals configured to enable an electrical current to pass through the magnetic free layer and the spin Hall layer in a direction that is perpendicular to a plane of the free and spin Hall layers, and a pair of sensing terminals configured to sense a voltage when the electrical current passes through the magnetic free layer and the spin Hall layer, where each of the push and sensing terminals is electrically isolated from the other terminals.

Abstract: An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse, and wherein the driving current comprises an AC component with a duty cycle selected based at least in part on a power constraint. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield, wherein the driving current comprises an AC component with a duty cycle based at least in part on a power constraint.

Abstract: An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse, and wherein the driving current comprises an AC component with a duty cycle selected based at least in part on a power constraint. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield, wherein the driving current comprises an AC component with a duty cycle based at least in part on a power constraint.

Abstract: Disclosed herein are apparatuses and methods for writing to a magnetic medium, and data storage devices comprising such apparatuses and methods. An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield of the magnetic write head, wherein the driving current comprises an AC component.

Abstract: A tunnel magnetoresistance (TMR) read head includes a first magnetic shield, a read sensor stripe located over the first magnetic shield, a second magnetic shield located over the sensor layer stack, an electrical isolation dielectric layer located on sidewalls of the read sensor stripe, and a pair of side shields located on the electrical isolation dielectric layer between the first magnetic shield and the second magnetic shield. The read sensor stripe includes a sensor layer stack containing a pinned layer stack, a non-magnetic electrically insulating barrier layer, and a ferromagnetic free layer. The side shields include nanocrystalline ferromagnetic particles, such as Fe, Co or CoFe, embedded in a non-magnetic dielectric material matrix, such as hafnium oxide.

Abstract: Magnetic sensors using spin Hall effect and methods for fabricating same are provided. One such magnetic sensor includes a spin Hall layer including an electrically conductive, non-magnetic material, a magnetic free layer adjacent to the spin Hall layer, a pair of push terminals configured to enable an electrical current to pass through the magnetic free layer and the spin Hall layer in a direction that is perpendicular to a plane of the free and spin Hall layers, and a pair of sensing terminals configured to sense a voltage when the electrical current passes through the magnetic free layer and the spin Hall layer, where each of the push and sensing terminals is electrically isolated from the other terminals.

Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

Abstract: A magnetic read apparatus has an air-bearing surface (ABS) and includes a read sensor and a rear magnetic bias structure. The read sensor includes first and second free layers, a spacer layer and a rear surface opposite to the ABS. The spacer layer is nonmagnetic and between the first and second free layers. The read sensor has a track width in a cross track direction parallel to the ABS. The rear magnetic bias structure magnetically biases the read sensor a stripe height direction perpendicular to the ABS. The read sensor is between the ABS and the rear magnetic bias structure. The rear magnetic bias structure has a width in the cross track direction and a length in the stripe height direction. The length is greater than the width. The width of the rear magnetic bias structure is substantially equal to the track width of the read sensor.

Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

Abstract: A method provides a magnetic read apparatus. A sensor stack is deposited. The read sensor is defined from the stack such that the sensor has sides forming a junction angle of 75 degrees-105 degrees from a sensor bottom. Defining the sensor includes performing a first ion mill at a first angle and a first energy and performing a second ion mill at a second angle greater than the first angle and at a second energy less than the first energy. The first angle is 5 degrees-30 degrees from normal to the top surface. After the first ion mill, less than half of the stack's bottom layer depth remains unmilled. Magnetic bias structure(s) adjacent to the sides may be formed. The magnetic bias structure(s) include a side shielding material having at least one of the saturation magnetization greater than 800 emu/cm3 and an exchange length less than five nanometers.

Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

Abstract: A magnetic read apparatus has an air-bearing surface (ABS) and includes a differential read sensor, side bias structure(s) and rear magnetic bias structure(s). The differential read sensor includes first and second free layers and a nonmagnetic spacer layer between the first and second free layers in a down-track direction. The side bias structure(s) are adjacent to the first and second free layers in a cross-track direction perpendicular to the down-track direction. The side bias structure(s) magnetically bias the first and second free layers in the cross-track direction. The differential read sensor is between the ABS and the rear magnetic bias structure(s). The rear magnetic bias structure(s) provide a first magnetic bias for the first free layer in a first direction along a stripe height direction perpendicular to the ABS and provide a second magnetic bias for the second free layer in a second direction opposite to the first direction.