Patents by Inventor Hirofumi Suto
Hirofumi Suto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9704552Abstract: According to one embodiment, a magnetic recording apparatus includes a spin-torque oscillator, a recording unit, and a controller. The spin-torque oscillator includes an oscillation layer. The recording unit includes at least one recording layer. Magnetization reversal in each recording layer is performed by excitation of cooperative dynamics between magnetization of the oscillation layer and magnetization of the recording layer. The controller controls precession of the magnetization of the oscillation layer, which is induced by application of an electric current to the spin-torque oscillator.Type: GrantFiled: October 29, 2015Date of Patent: July 11, 2017Assignee: Kabushiki Kaisha ToshibaInventors: Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Koichi Mizushima, Rie Sato
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Publication number: 20170061999Abstract: According to one embodiment, a magnetic recording medium includes a first magnetic layer and a second magnetic layer. An easy magnetization axis of the first magnetic layer is aligned with a first direction. The first direction is from the first magnetic layer toward the second magnetic layer. The second magnetic layer has magnetic anisotropy in a plane perpendicular to the first direction. A second magnetization of the second magnetic layer is reverse orientation of a first magnetization of the first magnetic layer.Type: ApplicationFiled: August 25, 2016Publication date: March 2, 2017Inventors: Hirofumi SUTO, Kiwamu Kudo, Tazumi Nagasawa, Taro Kanao, Rie Sato, Koichi Mizushima
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Patent number: 9437218Abstract: According to an embodiment, a magnetic recording head includes a main magnetic pole and a spin torque oscillator. The spin torque oscillator includes a first perpendicular free layer, a second perpendicular free layer, and a first spacer layer, each of the first perpendicular free layer and the second perpendicular free layer including a magnetic anisotropy axis in a direction perpendicular to a film plane of the spin torque oscillator. An effective perpendicular magnetic anisotropy magnetic field of the first perpendicular free layer is smaller than an effective perpendicular magnetic anisotropy magnetic field of the second perpendicular free layer, and a current is applied from the first perpendicular free layer side to the second perpendicular free layer side.Type: GrantFiled: July 10, 2015Date of Patent: September 6, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kiwamu Kudo, Hirofumi Suto, Tazumi Nagasawa, Koichi Mizushima, Rie Sato
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Publication number: 20160180906Abstract: According to one embodiment, a magnetic recording apparatus includes a spin-torque oscillator, a recording unit, and a controller. The spin-torque oscillator includes an oscillation layer. The recording unit includes at least one recording layer. Magnetization reversal in each recording layer is performed by excitation of cooperative dynamics between magnetization of the oscillation layer and magnetization of the recording layer. The controller controls precession of the magnetization of the oscillation layer, which is induced by application of an electric current to the spin-torque oscillator.Type: ApplicationFiled: October 29, 2015Publication date: June 23, 2016Inventors: Kiwamu KUDO, Tazumi NAGASAWA, Hirofumi SUTO, Koichi MIZUSHIMA, Rie SATO
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Publication number: 20160027455Abstract: According to an embodiment, a magnetic recording head includes a main magnetic pole and a spin torque oscillator. The spin torque oscillator includes a first perpendicular free layer, a second perpendicular free layer, and a first spacer layer, each of the first perpendicular free layer and the second perpendicular free layer including a magnetic anisotropy axis in a direction perpendicular to a film plane of the spin torque oscillator. An effective perpendicular magnetic anisotropy magnetic field of the first perpendicular free layer is smaller than an effective perpendicular magnetic anisotropy magnetic field of the second perpendicular free layer, and a current is applied from the first perpendicular free layer side to the second perpendicular free layer side.Type: ApplicationFiled: July 10, 2015Publication date: January 28, 2016Inventors: Kiwamu KUDO, Hirofumi SUTO, Tazumi NAGASAWA, Koichi MIZUSHIMA, Rie SATO
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Patent number: 9159342Abstract: According to an embodiment, a magnetic recording apparatus includes following elements. The spin torque oscillator generates a first oscillating magnetic field. The recording medium unit includes one or more recording medium layers which are stacked, each of the one or more recording medium layers including a recording medium and spin-wave lines each of which generates a second oscillating magnetic field. The write magnetic field source generates a write magnetic field. The controller is configured to control the spin torque oscillator, the spin-wave lines, and the write magnetic field source to simultaneously apply the write magnetic field, and the first and second oscillating magnetic fields to target medium magnetization in the recording medium.Type: GrantFiled: September 11, 2014Date of Patent: October 13, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Tao Yang, Koichi Mizushima, Rie Sato
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Patent number: 9070389Abstract: According to an embodiment, a magnetic recording and reproducing apparatus includes a recording medium and a reproducing head. The recording medium includes a concentric circular plurality of tracks. The reproducing head includes a spin torque oscillator and reproduces information from the recording medium using the spin torque oscillator, the spin torque oscillator including an oscillation layer with a first cross-track direction width, a polarizer layer with a second cross-track direction width, and a spacer layer provided between the oscillation layer and the polarizer layer. The first cross-track direction width is larger than double the second cross-track direction width, and the second cross-track direction width is smaller than an inter-track distance.Type: GrantFiled: June 25, 2014Date of Patent: June 30, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Tao Yang, Koichi Mizushima, Rie Sato
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Publication number: 20150077883Abstract: According to an embodiment, a magnetic recording apparatus includes following elements. The spin torque oscillator generates a first oscillating magnetic field. The recording medium unit includes one or more recording medium layers which are stacked, each of the one or more recording medium layers including a recording medium and spin-wave lines each of which generates a second oscillating magnetic field. The write magnetic field source generates a write magnetic field. The controller is configured to control the spin torque oscillator, the spin-wave lines, and the write magnetic field source to simultaneously apply the write magnetic field, and the first and second oscillating magnetic fields to target medium magnetization in the recording medium.Type: ApplicationFiled: September 11, 2014Publication date: March 19, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Kiwamu KUDO, Tazumi NAGASAWA, Hirofumi SUTO, Tao Yang, Koichi MIZUSHIMA, Rie SATO
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Patent number: 8947170Abstract: According to one embodiment, a spin-torque oscillator includes a non-magnetic unit, one or more first magnetic unit, and a second magnetic unit. The non-magnetic unit is formed of a non-magnetic body. The one or more first magnetic unit is connected to the non-magnetic unit and generates a pure spin current indicating the flow of the electron spin that does not accompany an electric charge current. The second magnetic unit is connected to the non-magnetic unit in a manner such that a distance between the second magnetic unit and the first magnetic unit is shorter than a spin diffusion length indicating a distance that an electronic spin polarization is maintained in the non-magnetic unit. The second magnetic unit oscillates by the pure spin current.Type: GrantFiled: September 6, 2012Date of Patent: February 3, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Tao Yang, Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Rie Sato, Koichi Mizushima
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Publication number: 20140376129Abstract: According to an embodiment, a magnetic recording and reproducing apparatus includes a recording medium and a reproducing head. The recording medium includes a concentric circular plurality of tracks. The reproducing head includes a spin torque oscillator and reproduces information from the recording medium using the spin torque oscillator, the spin torque oscillator including an oscillation layer with a first cross-track direction width, a polarizer layer with a second cross-track direction width, and a spacer layer provided between the oscillation layer and the polarizer layer. The first cross-track direction width is larger than double the second cross-track direction width, and the second cross-track direction width is smaller than an inter-track distance.Type: ApplicationFiled: June 25, 2014Publication date: December 25, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Tao Yang, Koichi Mizushima, Rie Sato
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Patent number: 8896973Abstract: A magnetic head according to an embodiment includes: a spin-torque oscillator comprising a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer provided on the opposite side of the second ferromagnetic layer from the first ferromagnetic layer, a first nonmagnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, a second nonmagnetic layer provided between the second ferromagnetic layer and the third ferromagnetic layer, a first electrode provided on a surface on the opposite side of the first ferromagnetic layer from the first nonmagnetic layer, and a second electrode provided on a surface on the opposite side of the third ferromagnetic layer from the second nonmagnetic layer. Magnetization precession is induced in each of the first through third ferromagnetic layers when current is applied between the first and second electrodes.Type: GrantFiled: October 19, 2012Date of Patent: November 25, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tazumi Nagasawa, Hirofumi Suto, Kiwamu Kudo, Rie Sato, Koichi Mizushima, Tao Yang
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Patent number: 8861120Abstract: According to one embodiment, a magnetic medium includes at least one recording layer including a first magnetic layer, a second magnetic layer and a non-magnetic layer. The first magnetic layer is form of a first magnetic material having a first magnetic anisotropy. The second magnetic layer is made of a second magnetic material having a second magnetic anisotropy different from the first magnetic anisotropy. The non-magnetic layer is made of a non-magnetic material and between the first and second magnetic layers, the first magnetic layer and the second magnetic layer being coupled such that directions of magnetization of the first and second magnetic layers are opposed to each other.Type: GrantFiled: August 10, 2012Date of Patent: October 14, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tao Yang, Hirofumi Suto, Tazumi Nagasawa, Kiwamu Kudo, Rie Sato, Koichi Mizushima
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Publication number: 20140247520Abstract: According to one embodiment, a magnetic storage medium includes a plurality of recording layers and a first non-magnetic layer. The plurality of recording layers each includes at least one first magnetic layer and at least one second magnetic layer. The first magnetic layer is made of a first magnetic material which has a first effective perpendicular magnetic anisotropy. Data is stored in first magnetic layer in accordance with a direction of magnetization. The second magnetic layer is made of a second magnetic material having a second effective perpendicular magnetic anisotropy smaller than the first effective perpendicular magnetic anisotropy. First magnetization of the first magnetic layer and second magnetization of the second magnetic layer are in magnetic coupling.Type: ApplicationFiled: December 12, 2013Publication date: September 4, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Tao YANG, Hirofumi Suto, Juwany Kudo, Tazumi Nagasawa, Rie Sato, Koichi Mizushima
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Patent number: 8755153Abstract: According to one embodiment, a reproducing head includes a spin-torque oscillator and a pair of shield parts. The spin-torque oscillator has a first surface facing a magnetic recording medium. The pair of shield parts each has a second surface facing the magnetic recording medium, the spin-torque oscillator being arranged between the shield parts. A distance between the second surface and the magnetic recording medium is shorter than a distance between the first surface and the magnetic recording medium.Type: GrantFiled: June 28, 2012Date of Patent: June 17, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kiwamu Kudo, Tazumi Nagasawa, Koichi Mizushima, Rie Sato, Tao Yang, Hirofumi Suto
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Patent number: 8724261Abstract: According to one embodiment, a high-frequency magnetic field generation element includes a first fixed layer, a first free layer, and a second free layer. A direction of a magnetization of the first fixed layer is fixed and has a component parallel to a first direction. A direction of a magnetization of the first free layer is variable and has a component orthogonal to the first direction. A direction of a magnetization of the second free layer is variable and has a component orthogonal to the first direction. The first fixed layer is provided between the first free layer and the second free layer. The magnetizations of the first free layer and the second free layer oscillate. A rotation direction of the magnetization of the first free layer is opposite to a rotation direction of the magnetization of the second free layer.Type: GrantFiled: November 15, 2012Date of Patent: May 13, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Hirofumi Suto, Tao Yang, Tazumi Nagasawa, Kiwamu Kudo, Rie Sato, Koichi Mizushima
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Patent number: 8553358Abstract: According to one embodiment, a magnetic head for reading data from a magnetic recording medium by utilizing a magnetic resonance phenomenon includes an auxiliary magnetic pole, a first oscillator, and a second oscillator. The auxiliary magnetic pole is to apply a magnetic field to the magnetic recording medium. The first oscillator is to oscillate at a first frequency and apply, to the magnetic recording medium, a first high-frequency magnetic field corresponding to the first frequency. The second oscillator to oscillate at a second frequency different from the first frequency and apply, to the magnetic recording medium, a second high-frequency magnetic field corresponding to the second frequency.Type: GrantFiled: March 23, 2012Date of Patent: October 8, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Mizushima, Rie Sato, Hirofumi Suto, Tao Yang
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Publication number: 20130120875Abstract: According to one embodiment, a high-frequency magnetic field generation element includes a first fixed layer, a first free layer, and a second free layer. A direction of a magnetization of the first fixed layer is fixed and has a component parallel to a first direction. A direction of a magnetization of the first free layer is variable and has a component orthogonal to the first direction. A direction of a magnetization of the second free layer is variable and has a component orthogonal to the first direction. The first fixed layer is provided between the first free layer and the second free layer. The magnetizations of the first free layer and the second free layer oscillate. A rotation direction of the magnetization of the first free layer is opposite to a rotation direction of the magnetization of the second free layer.Type: ApplicationFiled: November 15, 2012Publication date: May 16, 2013Inventors: Hirofumi SUTO, Tao Yang, Tazumi Nagasawa, Kiwamu Kudo, Rle Sato, Koichi Mizushima
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Publication number: 20130107395Abstract: A magnetic head according to an embodiment includes: a spin-torque oscillator comprising a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer provided on the opposite side of the second ferromagnetic layer from the first ferromagnetic layer, a first nonmagnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, a second nonmagnetic layer provided between the second ferromagnetic layer and the third ferromagnetic layer, a first electrode provided on a surface on the opposite side of the first ferromagnetic layer from the first nonmagnetic layer, and a second electrode provided on a surface on the opposite side of the third ferromagnetic layer from the second nonmagnetic layer. Magnetization precession is induced in each of the first through third ferromagnetic layers when current is applied between the first and second electrodes.Type: ApplicationFiled: October 19, 2012Publication date: May 2, 2013Inventors: Tazumi Nagasawa, Hirofumi Suto, Kiwamu Kudo, Rie Sato, Koichi Mizushima, Tao Yang
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Publication number: 20130070361Abstract: According to one embodiment, a magnetic medium includes at least one recording layer including a first magnetic layer, a second magnetic layer and a non-magnetic layer. The first magnetic layer is form of a first magnetic material having a first magnetic anisotropy. The second magnetic layer is made of a second magnetic material having a second magnetic anisotropy different from the first magnetic anisotropy. The non-magnetic layer is made of a non-magnetic material and between the first and second magnetic layers, the first magnetic layer and the second magnetic layer being coupled such that directions of magnetization of the first and second magnetic layers are opposed to each other.Type: ApplicationFiled: August 10, 2012Publication date: March 21, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tao Yang, Hirofumi Suto, Tazumi Nagasawa, Kiwamu Kudo, Rie Sato, Koichi Mizushima
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Publication number: 20130069730Abstract: According to one embodiment, a spin-torque oscillator includes a non-magnetic unit, one or more first magnetic unit, and a second magnetic unit. The non-magnetic unit is formed of a non-magnetic body. The one or more first magnetic unit is connected to the non-magnetic unit and generates a pure spin current indicating the flow of the electron spin that does not accompany an electric charge current. The second magnetic unit is connected to the non-magnetic unit in a manner such that a distance between the second magnetic unit and the first magnetic unit is shorter than a spin diffusion length indicating a distance that an electronic spin polarization is maintained in the non-magnetic unit. The second magnetic unit oscillates by the pure spin current.Type: ApplicationFiled: September 6, 2012Publication date: March 21, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tao Yang, Kiwamu Kudo, Tazumi Nagasawa, Hirofumi Suto, Rie Sato, Koichi Mizushima