Patents by Inventor Eiji Kitagawa

Eiji Kitagawa 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).

  • Patent number: 8937832
    Abstract: According to one embodiment, a magnetic memory includes a magnetoresistive element. The element includes a first magnetic film having a variable magnetization perpendicular to a film surface, a second magnetic film having an invariable magnetization perpendicular to the film surface, a nonmagnetic film between the first and second magnetic films, a magnetic field application layer including a third magnetic film having a magnetization parallel to the film surface. The third magnetic film applies a magnetic field parallel to the film surface to the first magnetic film. A magnitude of the magnetization of the third magnetic film when supplying a read current is larger than a magnitude of the magnetization of the third magnetic film when supplying a write current.
    Type: Grant
    Filed: September 18, 2012
    Date of Patent: January 20, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Daisuke Saida, Naoharu Shimomura
  • Patent number: 8930173
    Abstract: A vehicle behavior estimation device includes: a storage unit configured to store a restriction condition at a point of a vehicle for which behavior is estimated; vehicle state data that includes position information and speed information of the vehicle; behavior parameters that include speed information and acceleration information of the vehicle; and physical restriction conditions that include an upper limit and a lower limit of the acceleration information; and a processor configured to obtain the vehicle state data by using the restriction condition at the point; calculate behavior parameters of a vehicle model that satisfy a physical restriction condition from the vehicle state data and the restriction condition at the point; update the vehicle state data of the vehicle model based on the behavior parameters; and repeat processing to calculate behavior parameters by using the updated vehicle state data and to update the vehicle state data.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: January 6, 2015
    Assignee: Fujitsu Limited
    Inventors: Takuro Ikeda, Eiji Kitagawa
  • Patent number: 8895162
    Abstract: A magnetoresistive element according to an embodiment includes: a base layer; a first magnetic layer formed on the base layer and having a changeable magnetization direction with an easy axis of magnetization in a direction perpendicular to a film plane; a first nonmagnetic layer formed on the first magnetic layer; and a second magnetic layer formed on the first nonmagnetic layer and having a fixed magnetization layer with an easy axis of magnetization in a direction perpendicular to the film plane. The first magnetic layer includes a ferrimagnetic layer having a DO22 structure or an L10 structure, the ferrimagnetic layer has a c-axis oriented in a direction perpendicular to the film plane, and the magnetization direction of the first magnetic layer is changeable by a current flowing through the first magnetic layer, the first nonmagnetic layer, and the second magnetic layer.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: November 25, 2014
    Assignees: Kabushiki Kaisha Toshiba, National University Corporation Tohoku University
    Inventors: Katsuya Nishiyama, Shigemi Mizukami, Terunobu Miyazaki, Hiroaki Yoda, Tadashi Kai, Tatsuya Kishi, Daisuke Watanabe, Mikihiko Oogane, Yasuo Ando, Masatoshi Yoshikawa, Toshihiko Nagase, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Chunlan Feng
  • Patent number: 8878324
    Abstract: The present invention relates to a magnetoresistive element including a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, a third magnetic layer. The first magnetic layer includes a magnetic film of MnxGey (77 atm %?x?82 atm %, 18 atm %?y?23 atm %, x+y=100 atm %). The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The third magnetic layer is provided between the first magnetic layer and the first nonmagnetic layer or between the second magnetic layer and the first nonmagnetic layer, or is provided between the first magnetic layer and the first nonmagnetic layer and between the second magnetic layer and the first nonmagnetic layer. The third magnetic layer includes a Heusler alloy. The present invention also relates to a magnetic memory containing the magnetoresistive element.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: November 4, 2014
    Assignees: Kabushiki Kaisha Toshiba, Tohoku University
    Inventors: Yushi Kato, Tadaomi Daibou, Eiji Kitagawa, Takao Ochiai, Takahide Kubota, Shigemi Mizukami, Terunobu Miyazaki
  • Patent number: 8879307
    Abstract: A magnetoresistive device of an embodiment includes: first and second devices each including, a first magnetic layer having a changeable magnetization perpendicular to a film plane, a second magnetic layer having a fixed and perpendicular magnetization, and a nonmagnetic layer interposed between the first and second magnetic layers, the first and second devices being disposed in parallel on a first face of an interconnect layer; and a TMR device including a third magnetic layer having perpendicular magnetic anisotropy and having a changeable magnetization, a fourth magnetic layer having a fixed magnetization parallel to a film plane, and a tunnel barrier layer interposed between the third and fourth magnetic layers, the TMR device being disposed on a second face of the interconnect layer, and the third magnetic layer being magnetostatically coupled to the first magnetic layers of the first and second devices.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Naoharu Shimomura, Hiroaki Yoda, Junichi Ito, Minoru Amano, Chikayoshi Kamata, Keiko Abe
  • Patent number: 8849625
    Abstract: A simulator used in a distributed process simulation includes: a storage unit configured to store map information, agent information, and area allocation information; a simulation execution unit; a condition determination unit configured to determine the condition of the reference agent to be referenced by the simulation execution unit based on a movement state of the agent; an allocation discrimination unit configured to discriminate another computer allocated an area in which the reference agent corresponding to the condition can be located; and an agent information acquisition unit configured to acquire the information about the agent satisfying the condition of the reference agent from the other discriminated computer.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: September 30, 2014
    Assignee: Fujitsu Limited
    Inventors: Takuro Ikeda, Eiji Kitagawa, Hiroshi Yamada
  • Publication number: 20140264673
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer having a variable magnetization direction; a second magnetic layer having an invariable magnetization direction; and a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO film, wherein the MgFeO film contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 18, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Eiji Kitagawa, Takao Ochiai, Kay Yakushiji, Makoto Konoto, Hitoshi Kubota, Shinji Yuasa, Takayuki Nozaki, Akio Fukushima
  • Publication number: 20140269038
    Abstract: A magnetic memory according to an embodiment includes at least one MTJ element, the MTJ element including: a magnetic multilayer structure including a first magnetic layer in which a direction of magnetization is fixed, a second magnetic layer in which a direction of magnetization is changeable, and a tunnel barrier layer located between the first and second magnetic layers; a first electrode provided on a first surface of the magnetic multilayer structure; a second electrode provided on a second surface of the magnetic multilayer structure; an insulating film provided on a side surface of the magnetic multilayer structure; and a control electrode provided on the side surface of the magnetic multilayer structure with the insulating film located therebetween, a voltage being applied to the control electrode in a read operation, which increases an energy barrier for changing the magnetization of the second magnetic layer.
    Type: Application
    Filed: March 6, 2014
    Publication date: September 18, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu SHIMOMURA, Eiji KITAGAWA, Minoru AMANO, Daisuke SAIDA, Kay YAKUSHIJI, Takayuki NOZAKI, Shinji YUASA, Akio FUKUSHIMA, Hiroshi IMAMURA, Hitoshi KUBOTA
  • Patent number: 8803267
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic film having a variable magnetization direction, a second magnetic film having an invariable magnetization direction, and a magnesium oxide film provided between the first magnetic film and the second magnetic film and being in contact with both the first magnetic film and the second magnetic film, and doped with at least one element selected from a first group consisting of copper, silver, and gold.
    Type: Grant
    Filed: September 18, 2012
    Date of Patent: August 12, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Tadaomi Daibou, Yushi Kato
  • Patent number: 8787077
    Abstract: According to one embodiment, a nonvolatile memory device includes a memory unit and a control unit. The memory unit includes a magnetic memory element which includes: a first and second ferromagnetic layers; and a first nonmagnetic layer provided between the first and the second ferromagnetic layers. The memory unit includes a magnetic field application unit configured to apply a magnetic field to the second ferromagnetic layer, the magnetic field having a component in a first in-plane direction perpendicular to a stacking direction. The control unit is electrically connected to the magnetic memory element, and is configured to implement a setting operation of changing a voltage between the first and the second ferromagnetic layers from a first set voltage to a second set voltage. The magnetic field applied by the magnetic field application unit satisfies the condition of ? ? ? H > ( H u + H dx ) ? ( H u + H dx - H ext ) ( H u + H dx + H ext ) .
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: July 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Saida, Naoharu Shimomura, Minoru Amano, Eiji Kitagawa, Yoshishige Suzuki
  • Patent number: 8750029
    Abstract: According to one embodiment, a magnetoresistive effect element includes a recording layer including ferromagnetic material with perpendicular magnetic anisotropy to a film surface and a variable orientation of magnetization, a reference layer including ferromagnetic material with perpendicular magnetic anisotropy to a film surface and an invariable orientation of magnetization, a nonmagnetic layer between the recording layer and the reference layer, a first underlayer on a side of the recoding layer opposite to a side on which the nonmagnetic layer is provided, and a second underlayer between the recording layer and the first underlayer. The second underlayer is a Pd film including a concentration of 3×1015 atms/cm2.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: June 10, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Tadaomi Daibou, Tadashi Kai, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Hiroaki Yoda
  • Patent number: 8750030
    Abstract: According to one embodiment, a magnetoresistive element includes an electrode layer, a first magnetic layer, a second magnetic layer and a nonmagnetic layer. The electrode layer includes a metal layer including at least one of Mo, Nb, and W. The first magnetic layer is disposed on the metal layer to be in contact with the metal layer and has a magnetization easy axis in a direction perpendicular to a film plane and is variable in magnetization direction. The second magnetic layer is disposed on the first magnetic layer and has a magnetization easy axis in the direction perpendicular to the film plane and is invariable in magnetization direction. The nonmagnetic layer is provided between the first and second magnetic layers. The magnetization direction of the first magnetic layer is varied by a current that runs through the first magnetic layer, the nonmagnetic layer, and the second magnetic layer.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: June 10, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Ueda, Tadashi Kai, Toshihiko Nagase, Katsuya Nishiyama, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Hiroaki Yoda
  • Publication number: 20140145279
    Abstract: The present invention relates to a magnetoresistive element including a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, a third magnetic layer. The first magnetic layer includes a magnetic film of MnxGey (77 atm %?x?82 atm %, 18 atm %?y?23 atm %, x+y=100 atm %). The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The third magnetic layer is provided between the first magnetic layer and the first nonmagnetic layer or between the second magnetic layer and the first nonmagnetic layer, or is provided between the first magnetic layer and the first nonmagnetic layer and between the second magnetic layer and the first nonmagnetic layer. The third magnetic layer includes a Heusler alloy.
    Type: Application
    Filed: January 30, 2014
    Publication date: May 29, 2014
    Applicants: Tohoku University, Kabushiki Kaisha Toshiba
    Inventors: Yushi KATO, Tadaomi Daibou, Eiji Kitagawa, Takao Ochiai, Takahide Kubota, Shigemi Mizukami, Terunobu Miyazaki
  • Publication number: 20140131649
    Abstract: According to one embodiment, a magnetoresistance element includes a first magnetic layer having first and second surfaces, a second magnetic layer, an intermediate layer provided between the first surface and the second magnetic layer, a first layer provided on the second surface, containing B and at least one element selected from Hf, Al, Mg, and Ti and having third and fourth surfaces, a second layer provided on the fourth surface and containing B and at least one element selected from Hf, Al, and Mg, and an insulating layer provided on a sidewall of the intermediate layer and containing at least one element selected from the Hf, Al, and Mg contained in the second layer.
    Type: Application
    Filed: September 11, 2013
    Publication date: May 15, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tadaomi DAIBOU, Eiji KITAGAWA, Chikayoshi KAMATA, Saori KASHIWADA, Yushi KATO, Megumi YAKABE
  • Publication number: 20140131823
    Abstract: According to one embodiment, a magnetoresistive element includes first and second magnetic layers and a first nonmagnetic layer. The first magnetic layer has an axis of easy magnetization perpendicular to a film plane, and a variable magnetization. The second magnetic layer has an axis of easy magnetization perpendicular to a film plane, and an invariable magnetization. The first nonmagnetic layer is provided between the first and second magnetic layers. The second magnetic layer includes third and fourth magnetic layers, and a second nonmagnetic layer formed between the third and fourth magnetic layers. The third magnetic layer is in contact with the first nonmagnetic layer and includes Co and at least one of Zr, Nb, Mo, Hf, Ta, and W.
    Type: Application
    Filed: January 20, 2014
    Publication date: May 15, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshihiko Nagase, Eiji Kitagawa, Katsuya Nishiyama, Tadashi Kai, Koji Ueda, Daisuke Watanabe
  • Publication number: 20140131824
    Abstract: According to one embodiment, a magnetoresistive element includes a recording layer having magnetic anisotropy perpendicular to a film surface and having a variable magnetization direction, a reference layer having magnetic anisotropy perpendicular to a film surface and having an invariable magnetization direction, an intermediate layer provided between the recording layer and the reference layer, and a underlayer containing AlTiN and provided on an opposite side of a surface of the recording layer on which the intermediate layer is provided.
    Type: Application
    Filed: January 21, 2014
    Publication date: May 15, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Tadashi Kai, Hiroaki Yoda
  • Patent number: 8716819
    Abstract: According to one embodiment, a magnetic random access memory includes a plurality of magnetoresistance elements. The plurality of magnetoresistance elements each include a recording layer having magnetic anisotropy perpendicular to a film surface, and a variable magnetization direction, a reference layer having magnetic anisotropy perpendicular to a film surface, and an invariable magnetization direction, and a first nonmagnetic layer formed between the recording layer and the reference layer. The recording layer is physically separated for each of the plurality of magnetoresistance elements. The reference layer and the first nonmagnetic layer continuously extend over the plurality of magnetoresistance elements.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Kitagawa, Naoharu Shimomura, Tsuneo Inaba
  • Publication number: 20140119109
    Abstract: According to one embodiment, a magnetoresistive element includes first and second magnetic layers, a first nonmagnetic layer, a conductive layer. The first and second magnetic layers have axes of easy magnetization perpendicular to a film plane. The first and second magnetic layers have variable and invariable magnetization directions, respectively. The first nonmagnetic layer is between the first and second magnetic layers. The conductive layer is on a surface of the first magnetic layer opposite to a surface on which the first nonmagnetic layer is formed. The first magnetic layer has a structure obtained by alternately laminating magnetic and nonmagnetic materials. The nonmagnetic material includes at least one of Ta, W, Nb, Mo, Zr, Hf. The magnetic material includes Co and Fe. One of the magnetic materials contacts the first nonmagnetic layer. One of the nonmagnetic materials contacts the conductive layer.
    Type: Application
    Filed: January 3, 2014
    Publication date: May 1, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Daisuke Watanabe, Koji Ueda, Katsuya Nishiyama, Eiji Kitagawa, Kenji Noma, Tadashi Kai
  • Patent number: 8705269
    Abstract: A magnetoresistive element according to an embodiment includes: a first and second magnetic layers having an easy axis of magnetization in a direction perpendicular to a film plane; and a first nonmagnetic layer interposed between the first and second magnetic layers, at least one of the first and second magnetic layers including a structure formed by stacking a first and second magnetic films, the second magnetic film being located closer to the first nonmagnetic layer, the second magnetic film including a structure formed by repeating stacking of a magnetic material layer and a nonmagnetic material layer at least twice, the nonmagnetic material layers of the second magnetic film containing at least one element selected from the group consisting of Ta, W, Hf, Zr, Nb, Mo, Ti, V, and Cr, one of the first and second magnetic layers having a magnetization direction that is changed by applying a current.
    Type: Grant
    Filed: September 14, 2011
    Date of Patent: April 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Nagase, Tadashi Kai, Makoto Nagamine, Katsuya Nishiyama, Eiji Kitagawa, Tadaomi Daibou, Koji Ueda, Hiroaki Yoda, Kay Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
  • Patent number: 8686521
    Abstract: A magnetoresistive element includes a stabilization layer, a nonmagnetic layer, a spin-polarization layer provided between the stabilization layer and the nonmagnetic layer, the spin-polarization layer having magnetic anisotropy in a perpendicular direction, and a magnetic layer provided on a side of the nonmagnetic layer opposite to a side on which the spin-polarization layer is provided. The stabilization layer has a lattice constant smaller than that of the spin-polarization layer in an in-plane direction. The spin-polarization layer contains at least one element selected from a group consisting of cobalt (Co) and iron (Fe), has a body-centered tetragonal (BCT) structure, and has a lattice constant ratio c/a of 1.10 (inclusive) to 1.35 (inclusive) when a perpendicular direction is a c-axis and an in-plane direction is an a-axis.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: April 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadaomi Daibou, Toshihiko Nagase, Eiji Kitagawa, Masatoshi Yoshikawa, Katsuya Nishiyama, Makoto Nagamine, Tatsuya Kishi, Hiroaki Yoda