Abstract: According to one embodiment, a magnetic recording head records information in a magnetic recording medium by shingled magnetic recording. The magnetic recording head includes a magnetic pole and a shield opposing the magnetic pole. The magnetic pole has a shield-opposing surface opposing the shield. The shield-opposing surface includes a first portion and a second portion. A position of the second portion in a track width direction is different from a position of the first portion in the track width direction, the track width direction intersecting a first direction from the magnetic pole toward the shield. The first portion records the information in the magnetic recording medium after the second portion in the shingled magnetic recording. A first distance between the first portion and the shield is shorter than a second distance between the second portion and the shield. The shield-opposing surface is tilted with respect to the first direction.

Abstract: According to one embodiment, a spin-valve element includes a nonmagnetic unit, a first magnetic unit, a second magnetic unit, a third magnetic unit, a current source, and a voltage sensor. The current source is connected to the second magnetic unit and the third magnetic unit. The current source causes a current to flow between the second magnetic unit and the third magnetic unit via the nonmagnetic unit. The voltage sensor is connected to the second magnetic unit and the third magnetic unit. A maximum length of a contact surface between the first magnetic unit and the nonmagnetic unit is not more than a spin diffusion length of the nonmagnetic unit. A length of the first magnetic unit in a direction orthogonal to the contact surface is not more than 3 times a spin diffusion length of the first magnetic unit. The first magnetic unit does not contact an external electrode.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole and a shield. The shield has a first opposing surface opposing the magnetic pole. The first opposing surface includes a first opposing portion. The magnetic pole and the first opposing portion overlap in a first direction from the magnetic pole toward the shield. The first opposing portion includes a first protrusion.

Abstract: According to one embodiment, a magnetoresistance effect element includes first and second shields, first and second side magnetic units, a stacked body, and a hard bias unit. The first side magnetic unit includes a first soft magnetic layer, a first nonmagnetic intermediate layer, and a second soft magnetic layer. The second side magnetic unit includes a third soft magnetic layer, a second nonmagnetic intermediate layer, and a fourth soft magnetic layer. The stacked body includes a fifth ferromagnetic layer, a third nonmagnetic intermediate layer, and a sixth ferromagnetic layer. The hard bias unit is provided between the first and second shields. A first distance between the first and fifth magnetic layers is shorter than a second distance between the second and sixth magnetic layers. A third distance between the third and fifth magnetic layers is shorter than a fourth distance between the fourth and sixth magnetic layers.

Abstract: According to one embodiment, a spin-valve element includes a nonmagnetic unit, a first magnetic unit, a second magnetic unit, a third magnetic unit, a current source, and a voltage sensor. The current source is connected to the second magnetic unit and the third magnetic unit. The current source causes a current to flow between the second magnetic unit and the third magnetic unit via the nonmagnetic unit. The voltage sensor is connected to the second magnetic unit and the third magnetic unit. A maximum length of a contact surface between the first magnetic unit and the nonmagnetic unit is not more than a spin diffusion length of the nonmagnetic unit. A length of the first magnetic unit in a direction orthogonal to the contact surface is not more than 3 times a spin diffusion length of the first magnetic unit. The first magnetic unit does not contact an external electrode.

Abstract: A magnetic recording and reproducing device according to an embodiment includes a magnetic recording medium and a controller. The magnetic recording medium includes in sequence a substrate, a storage layer, an exchange layer, and a surface recording layer. The controller executes following steps (1) to (6): (1) magnetically recording first information on the surface recording layer; (2) transferring the first information recorded on the surface recording layer to the storage layer; (3) magnetically recording second information on the surface recording layer; (4) magnetically reproducing the second information from the surface recording layer; (5) transferring the first information recorded on the storage layer to the surface recording layer; and (6) magnetically reproducing the first information transferred to the surface recording layer.

Abstract: A method for measuring the frequency in a spin torque oscillator having at least a magnetic oscillation layer (MOL), junction layer, and magnetic reference layer (MRL) is disclosed. In a first embodiment, a small in-plane magnetic field is applied to the STO after a DC current is applied to excite the MOL into an oscillation state. The MRL has a perpendicular magnetization that is tilted slightly to give an in-plane magnetization component to serve as a reference layer for measuring the oscillation frequency of the MOL in-plane magnetization component. An AC voltage change is produced in the DC current as a result of variable STO resistance and directly correlates to MOL oscillation frequency. Alternatively, a field having both perpendicular and in-plane components may be applied externally or by forming the STO between two magnetic poles thereby producing an in-plane magnetization reference component in the MRL.

Abstract: According to one embodiment, a magnetoresistance effect element includes first and second shields, first and second side magnetic units, a stacked body, and a hard bias unit. The first side magnetic unit includes a first soft magnetic layer, a first nonmagnetic intermediate layer, and a second soft magnetic layer. The second side magnetic unit includes a third soft magnetic layer, a second nonmagnetic intermediate layer, and a fourth soft magnetic layer. The stacked body includes a fifth ferromagnetic layer, a third nonmagnetic intermediate layer, and a sixth ferromagnetic layer. The hard bias unit is provided between the first and second shields. A first distance between the first and fifth magnetic layers is shorter than a second distance between the second and sixth magnetic layers. A third distance between the third and fifth magnetic layers is shorter than a fourth distance between the fourth and sixth magnetic layers.

Abstract: A magnetic head of an embodiment includes a stack, side shields, and a first and a second magnetic shield. The stack includes a pin layer having a fixed magnetization direction, a first free layer having a magnetization direction to change in accordance with an external magnetic field, a second free layer antiferromagnetically exchange-coupled with the first free layer and having a magnetization direction to change in accordance with the field, and an antiferromagnetic layer exchange-coupled with the second free layer. A magnetic field is applied from the side shields to the first and second free layers, and a direction of the magnetic field is substantially parallel to the magnetization direction of one of the first and second free layers and substantially antiparallel to the magnetization direction of the other, and a magnetic volume of the one is larger than a magnetic volume of the other.

Abstract: A magnetic head includes a first electrode layer, a metal magnetic layer, an organic molecular having a pi conjugated structure, an inorganic layer, and a second electrode layer.

Abstract: An example magnetoresistive element includes a nonmagnetic conductive layer; a first magnetic layer connected to the nonmagnetic conductive layer; a second magnetic layer connected to the nonmagnetic conductive layer so as to be distant from the first magnetic layer; a third magnetic layer connected to the nonmagnetic conductive layer so as be distant from the first magnetic layer; and first to third magnetic electrodes connected to the first to third magnetic layers respectively. A voltage is applied between the third magnetic electrode and the first magnetic electrode through the third magnetic layer, the nonmagnetic conductive layer, and the first magnetic layer, and a current is caused to flow between the third electrode and the second magnetic electrode through the third magnetic layer, the nonmagnetic conductive layer, and the second magnetic layer. The nonmagnetic conductive layer decreases in volume toward the one end face.

Abstract: According to one embodiment, a magnetic head includes a reproducing unit to detect a medium magnetic field recorded in a magnetic recording medium. The reproducing unit includes first and second magnetic shields, a stacked body, and a side wall film. The stacked body is provided between the first and second magnetic shields and includes first and second magnetic layer and an intermediate layer provided between them. The stacked body has a side wall. The side wall intersects a plane perpendicular to a stacking direction from the first magnetic shield toward the second magnetic shield. The side wall film covers at least a part of the side wall of the stacked body. The side wall film includes at least one of Fe and Co, and has a composition different from a composition of the first magnetic layer and different from a composition of the second magnetic layer.

Abstract: A magnetic head of an embodiment includes a stack, side shields, and a first and a second magnetic shield. The stack includes a pin layer having a fixed magnetization direction, a first free layer having a magnetization direction to change in accordance with an external magnetic field, a second free layer antiferromagnetically exchange-coupled with the first free layer and having a magnetization direction to change in accordance with the field, and an antiferromagnetic layer exchange-coupled with the second free layer. A magnetic field is applied from the side shields to the first and second free layers, and a direction of the magnetic field is substantially parallel to the magnetization direction of one of the first and second free layers and substantially antiparallel to the magnetization direction of the other, and a magnetic volume of the one is larger than a magnetic volume of the other.

Abstract: An example magnetic recording apparatus includes a magnetic recording medium, a magnetic recording head and a signal processor. The magnetic recording head includes a first magnetic pole to apply a recording magnetic field to the magnetic recording medium; a spin torque oscillator arranged parallel to the first magnetic pole; and a first coil to magnetize the first magnetic pole. The signal processor writes and reads a signal on the magnetic recording medium by using the magnetic recording head and includes a first current circuit to supply a recording current to the first coil, the recording current including a recording signal to be recorded on the magnetic recording medium. The recording current includes either one of a signal changing at a frequency higher than that of the recording signal, and a signal having the same frequency as the recording signal and changing an absolute value thereof in one cycle.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes magnetic recording medium and a magnetic head. The magnetic recording medium includes a first surface. A plurality of bits is provided in the first surface. Each of the bits has a direction of magnetization corresponding to recorded information. The magnetic head includes a reproducing unit. The reproducing unit senses the direction of magnetization. The reproducing unit includes a first shield, a second shield, a first magnetic layer, a second magnetic layer, a third magnetic layer, a fourth magnetic layer, an intermediate layer, a first nonmagnetic layer, and a second nonmagnetic layer. The first and the second nonmagnetic layers include at least one selected from ruthenium, copper, and tantalum. A distance between the first shield and the second shield is not less than 3 times and not more than 7 times a length of each of the bits.

Abstract: A magnetic head of an embodiment includes: a first electrode being a magnetic body having a magnetic shielding property; a first signal detector disposed on the first electrode and being a differential magnetoresistive effect element; a second electrode disposed on the first signal detector; an insulating layer disposed on the second electrode; a third electrode disposed on the insulating layer; a second signal detector disposed on the third electrode and being a differential magnetoresistive effect element; and a fourth electrode disposed on the second signal detector and being a magnetic body having a magnetic shielding property. At least one of the second electrode and the third electrode is a nonmagnetic metal.

Abstract: A magnetic head includes a first electrode layer, a metal magnetic layer, an organic molecular having a pi conjunction structure, an inorganic layer, and a second electrode layer.

Abstract: A magnetic recording apparatus of an embodiment includes: a main magnetic pole, in which a width of a leading edge at an air bearing surface facing the magnetic disk is wider than a width of a trailing edge at the air bearing surface; and a magnetic head assembly, a head slider and a suspension being bonded to each other so that an angle ? between a boundary line between an overlapping track and a track adjacent to the overlapping track in an opposite direction to an overlapping direction and a line obtained by extending a side of the main magnetic pole opposite to the overlapping direction at the air bearing surface is negative when a direction from the boundary line to the side is defined as a positive direction, the overlapping being performed in one direction from an inner circumference to an outer circumference of the magnetic disk.

Abstract: An example magnetic recording apparatus includes a magnetic recording medium, a magnetic recording head and a signal processor. The magnetic recording head includes a first magnetic pole; a second magnetic pole; a spin torque oscillator; a first coil to magnetize the first magnetic pole; and a second coil through which a current is passed independently of the first coil. The signal processor writes and reads a signal on the magnetic recording medium by using the magnetic recording head and includes a first current circuit to supply a recording current to the first coil and a second current circuit to supply a modulating current to the second coil.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes magnetic recording medium and a magnetic head. The magnetic recording medium includes a first surface. A plurality of bits is provided in the first surface. Each of the bits has a direction of magnetization corresponding to recorded information. The magnetic head includes a reproducing unit. The reproducing unit senses the direction of magnetization. The reproducing unit includes a first shield, a second shield, a first magnetic layer, a second magnetic layer, a third magnetic layer, a fourth magnetic layer, an intermediate layer, a first nonmagnetic layer, and a second nonmagnetic layer. The first and the second nonmagnetic layers include at least one selected from ruthenium, copper, and tantalum. A distance between the first shield and the second shield is not less than 3 times and not more than 7 times a length of each of the bits.