Abstract: According to one embodiment, a magnetic sensor includes a sensor part, a first circuit, and a second circuit. The sensor part includes a magnetic element part, first and second conductive members. The magnetic element part includes first to fourth magnetic elements. The first conductive member includes first to third conductive portions, and first and second middle portions. The second conductive member includes fourth to sixth conductive portions, and third and fourth middle portions. The first circuit is electrically connected to the third and sixth conductive portions. The first circuit is configured to supply a first current between the third and sixth conductive portions. The second circuit is electrically connected to a first connection point and a second connection point. The second circuit is electrically connected to first and second connection points. The second circuit is configured to supply a second current between the first and second connection points.

Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, a first nonmagnetic layer provided between the first and second magnetic layers, a second nonmagnetic layer provided between the second and third magnetic layers, and a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer. A first magnetic pole length of the first magnetic pole is less than a second magnetic pole length of the second magnetic pole. A first magnetic layer length of the first magnetic layer is greater than a second magnetic layer length of the second magnetic layer.

Abstract: According to one embodiment, a magnetic head includes a recording portion. The recording portion includes a magnetic pole, a shield, and a stacked body provided between the magnetic pole and the shield. The stacked body includes a first magnetic layer, a first layer provided between the first magnetic layer and the magnetic pole, and a first intermediate layer provided between the first magnetic layer and the shield. The first layer contacts the magnetic pole and includes at least one selected from the group consisting of IrMn, PtMn, FeMn, PdMn, NiMn, RhMn, MnCr, and PtCr. The first intermediate layer includes at least one selected from a first group consisting of Cu, Ag, Au, Al, Cr, and Ru.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.

Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first magnetic member and the second magnetic pole, a first layer provided between the first and second magnetic members, and a second layer provided between the second magnetic member and the second magnetic pole. The first magnetic member includes first magnetic regions and a first nonmagnetic region. The first nonmagnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions. The second magnetic member includes second magnetic regions and a second nonmagnetic region. The second nonmagnetic region is between the one of the second magnetic regions and the other one of the second magnetic regions.

Abstract: According to one embodiment, a magnetic sensor includes a first conductive part circuit, an alternating current circuit part, a first direct current circuit part, and a first element. The first conductive part circuit includes a first conductive part including a first conductive part end portion and a first conductive part other-end portion, and a first alternating current transfer element electrically connected in series with the first conductive part. The first conductive part circuit includes a first circuit end portion and a first circuit other-end portion. The alternating current circuit part is configured to apply an alternating current voltage between the first circuit end portion and the first circuit other-end portion. The first direct current circuit part is configured to apply a first direct current voltage to the first conductive part end portion and the first conductive part other-end portion. The first element includes a first magnetic layer.

Abstract: According to one embodiment, a magnetic sensor includes a first magnetic part, a first magnetic member, a second magnetic part, a second magnetic member, a first element, a second element, a third element, a fourth element, and a first interconnect. The first magnetic part includes first, second, and third portions. The first portion is between the second and third portions. The second magnetic part includes fourth, fifth, and sixth portions. The fourth portion is between the fifth and sixth portions. The first element includes a first magnetic layer. The second element includes a second magnetic layer. The third element includes a third magnetic layer. The fourth element includes a fourth magnetic layer. The first interconnect includes first and second interconnect portions.

Abstract: According to one embodiment, a magnetic sensor includes a first element. The first element includes a first magnetic part, a first magnetic layer, a first nonmagnetic portion, and a first intermediate magnetic layer. The first magnetic part includes first to third portions. The first portion is between the second and third portions. The first portion has a first length and a second length. The second portion has at least one of a third length longer than the first length or a fourth length longer than the second length. The third portion has at least one of a fifth length longer than the first length or a sixth length longer than the second length. The first nonmagnetic portion is provided between the first portion and the first magnetic layer. The first intermediate magnetic layer is provided between the first portion and the first nonmagnetic portion.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, a first magnetic layer, a second magnetic layer, a third magnetic layer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a fourth intermediate layer. The first magnetic layer is provided between the magnetic pole and the first shield. The second magnetic layer is provided between the first magnetic layer and the first shield. The third magnetic layer is provided between the second magnetic layer and the first shield. The first intermediate layer is provided between the magnetic pole and the first magnetic layer. The second intermediate layer is provided between the first magnetic layer and the second magnetic layer. The third intermediate layer is provided between the second magnetic layer and the third magnetic layer. The fourth intermediate layer is provided between the third magnetic layer and the first shield.

Abstract: According to one embodiment, a magnetic head includes a recording portion. The recording portion includes a magnetic pole, a shield, and a stacked body provided between the magnetic pole and the shield. The stacked body includes a first magnetic layer, a first layer provided between the first magnetic layer and the magnetic pole, and a first intermediate layer provided between the first magnetic layer and the shield. The first layer contacts the magnetic pole and includes at least one selected from the group consisting of IrMn, PtMn, FeMn, PdMn, NiMn, RhMn, MnCr, and PtCr. The first intermediate layer includes at least one selected from a first group consisting of Cu, Ag, Au, Al, Cr, and Ru.

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head, and an electrical circuit. The magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and the second magnetic poles. The stacked body includes a first nonmagnetic layer, a first magnetic layer provided between the first nonmagnetic layer and the second magnetic pole, a first layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the first layer and the second magnetic pole, a second magnetic layer provided between the second nonmagnetic layer and the second magnetic pole, and a third nonmagnetic layer provided between the second magnetic layer and the second magnetic pole. The electrical circuit supplies, to the stacked body, a first current having a first orientation from the second magnetic pole toward the first magnetic pole.

Abstract: According to one embodiment, a magnetic head includes first and second shields, a magnetic pole, a first magnetic layer, and a first nonmagnetic member. The first shield includes first, second, and third partial regions. A first direction is from the second toward third partial region. The first partial region is between the second and third partial regions. A second direction from the first toward second shield crosses the first direction. The magnetic pole between the second and third partial regions in the first direction is provided between the first partial region and the second shield in the second direction. The first magnetic layer is provided between the magnetic pole and the second shield. The first nonmagnetic member includes first and second portions. The first portion is between the magnetic pole and the first magnetic layer. The second portion is between the second partial region and the second shield.

Abstract: According to the embodiment, a magnetic recording device includes a magnetic head, a magnetic recording medium, and an electrical circuit. The magnetic head includes a magnetic pole, a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes first, and second magnetic layers, first, second, and third nonmagnetic layers. An electrical resistance of the stacked body is a first resistance when a current flowing in the stacked body is a first current. The electrical resistance is a second resistance when the current flowing in the stacked body is a second current. The electrical resistance oscillates when the current flowing in the stacked body is a third current. The electrical circuit is configured to supply the second current to the stacked body in a recording operation of using the magnetic head to record information in the magnetic recording medium.

Abstract: According to one embodiment, a magnetic recording device includes a magnetic head, and an electrical circuit. The magnetic head includes a magnetic pole, a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first magnetic layer, a second magnetic layer, a first layer provided between the first and second magnetic layers, and a first nonmagnetic layer provided between the first magnetic layer and the first layer. A change rate of an electrical resistance of the stacked body with respect to a change of a current density flowing in the stacked body has a first value when the current density is in a first range, a second value when the current density is in a second range, and a third value when the current density is in a third range.

Abstract: According to one embodiment, a magnetic sensor includes a first element. The first element includes a first magnetic part, a first magnetic layer, a first nonmagnetic portion, and a first intermediate magnetic layer. The first magnetic part includes first to third portions. The first portion is between the second and third portions. The first portion has a first length and a second length. The second portion has at least one of a third length longer than the first length or a fourth length longer than the second length. The third portion has at least one of a fifth length longer than the first length or a sixth length longer than the second length. The first nonmagnetic portion is provided between the first portion and the first magnetic layer. The first intermediate magnetic layer is provided between the first portion and the first nonmagnetic portion.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a first shield, a first magnetic layer, a second magnetic layer, a third magnetic layer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a fourth intermediate layer. The first magnetic layer is provided between the magnetic pole and the first shield. The second magnetic layer is provided between the first magnetic layer and the first shield. The third magnetic layer is provided between the second magnetic layer and the first shield. The first intermediate layer is provided between the magnetic pole and the first magnetic layer. The second intermediate layer is provided between the first magnetic layer and the second magnetic layer. The third intermediate layer is provided between the second magnetic layer and the third magnetic layer. The fourth intermediate layer is provided between the third magnetic layer and the first shield.

Abstract: According to one embodiment, a magnetic sensor includes a first sensor element and a first interconnect. The first sensor element includes a first magnetic layer, a first opposing magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the first opposing magnetic layer. A first magnetization of the first magnetic layer is aligned with a first length direction crossing a first stacking direction from the first magnetic layer toward the first opposing magnetic layer. At least a portion of the first interconnect extends along the first length direction. The first interconnect cross direction crosses the first length direction and is from the first sensor element toward the portion of the first interconnect. A first electrical resistance of the first sensor element changes according to an alternating current flowing in the first interconnect and a sensed magnetic field applied to the first sensor element.

Abstract: According to one embodiment, a magnetic sensor includes a first sensor element and a first interconnect. The first sensor element includes a first magnetic layer, a first opposing magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the first opposing magnetic layer. A first magnetization of the first magnetic layer is aligned with a first length direction crossing a first stacking direction from the first magnetic layer toward the first opposing magnetic layer. At least a portion of the first interconnect extends along the first length direction. The first interconnect cross direction crosses the first length direction and is from the first sensor element toward the portion of the first interconnect. A first electrical resistance of the first sensor element changes according to an alternating current flowing in the first interconnect and a sensed magnetic field applied to the first sensor element.

Abstract: According to one embodiment, a sensor includes a nonmagnetic layer and a plurality of magnetic field sensors. The nonmagnetic layer has a first surface and a second surface. The magnetic field sensors are arranged along the second surface. The second surface is between the first surface and the magnetic field sensors. Each of the magnetic field sensors includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the nonmagnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The intermediate layer is nonmagnetic. A distance between the first surface and the second magnetic layer is not more than a pitch of the magnetic field sensors.

Abstract: A semiconductor device including a semiconductor element and a first member is provided. The first member includes a first magnetic planar region separated from the semiconductor element in a first direction, and a first nonmagnetic planar region provided between the first magnetic planar region and the semiconductor element in the first direction. At least a portion of the first magnetic planar region includes Fe100-x1-x2?x1Nx2, where ? includes at least one selected from the group consisting of Zr, Hf, Ta, Nb, Ti, Si, and Al, x1 is not less than 0.5 atomic percent and not more than 10 atomic percent, and x2 is not less than 0.5 atomic percent and not more than 8 atomic percent.