Patents by Inventor Akira Kikitsu

Akira Kikitsu 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: 8976579
    Abstract: According to one embodiment, a magnetic memory element includes: a magnetic wire, a stress application unit, and a recording/reproducing unit. The magnetic wire includes a plurality of domain walls and a plurality of magnetic domains separated by the domain walls. The magnetic wire is a closed loop. The stress application unit is configured to cause the domain walls to circle around along the closed loop a plurality of times by applying stress to the magnetic wire. The recording/reproducing unit is configured to write memory information by changing magnetizations of the circling magnetic domains as the domain walls circle around and to read the written memory information by detecting the magnetizations of the circling magnetic domains.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: March 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yoshiaki Fukuzumi, Hirofumi Morise, Akira Kikitsu
  • Publication number: 20150055404
    Abstract: A magnetic memory device comprises a first electrode, a second electrode, a laminated structure comprising plural first magnetic layers being provided between the first electrode and the second electrode, a second magnetic layer comprising different composition elements from that of the first magnetic layer and being provided between plural first magnetic layers, a piezoelectric body provided on a opposite side to a side where the first electrode is provided in the laminated structure, and a third electrode applying voltage to the piezoelectric body and provided on a different position from a position where the first electrode is provided in the piezoelectric body.
    Type: Application
    Filed: June 20, 2014
    Publication date: February 26, 2015
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Patent number: 8958177
    Abstract: In one embodiment, there are provided: a substrate; a data area disposed on the substrate and having a plurality of first magnetic dots arrayed in lines in mutually different first, second, and third directions; and a boundary magnetic part having a plurality of first magnetic portions arrayed in a line in the third direction and each having a length longer than that of the first magnetic dot in the third direction, and a second magnetic dot disposed between the first magnetic portions and disposed on extensions in the first and second directions of the first magnetic dots, and disposed along with the data area on the substrate.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: February 17, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Kikitsu, Naoko Kihara, Yoshiyuki Kamata, Hiroyuki Hieda
  • Publication number: 20140374380
    Abstract: A stamper of an embodiment includes: a base portion having a main surface; and a plurality of guides arranged on the main surface in mutually different first and second directions and serving as references of arrangement of a plurality of self-assembled dots. A distance between the guides in a third direction is within a range of an integer m1±0.05 times of a pitch of the plural self-assembled dots. The third direction corresponds to a third vector obtained by combining a first vector corresponding to the arrangement of the guides in the first direction and a second vector corresponding to the arrangement of the guides in the second direction. A distance between the plural guides in the first direction falls out of a range of an integer m2±0.15 times of the pitch of the plural self-assembled dots.
    Type: Application
    Filed: January 29, 2014
    Publication date: December 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masahiro KANAMARU, Yoshiyuki KAMATA, Ryosuke YAMAMOTO, Takeshi OKINO, Akira KIKITSU, Katsuya SUGAWARA, Yasuaki OOTERA, Tomoyuki MAEDA
  • Patent number: 8837087
    Abstract: According to one embodiment, there is provided a thin magnetic film having a negative anisotropy of ?6×106 erg/cm3 or less and including, on at least a nonmagnetic substrate, at least one seed layer made of a metal or metal compound, a ruthenium underlayer for controlling the orientation of an immediately overlying layer, and a magnetic layer having negative anisotropy in the normal line direction perpendicular to a surface of the magnetic layer and mainly containing Co and Ir, wherein the additive element concentration of Ir in the magnetic layer is 10 (inclusive) to 45 (inclusive) at %.
    Type: Grant
    Filed: July 19, 2013
    Date of Patent: September 16, 2014
    Assignees: Kabushiki Kaisha Toshiba, Tohoku University, Showa Denko K.K.
    Inventors: Akihiko Takeo, Akira Kikitsu, Tomoyuki Maeda, Migaku Takahashi, Shin Saito, Ken Inoue, Gohei Kurokawa
  • Patent number: 8792271
    Abstract: A magnetic memory device comprises a first electrode, a second electrode, a laminated structure comprising plural first magnetic layers being provided between the first electrode and the second electrode, a second magnetic layer comprising different composition elements from that of the first magnetic layer and being provided between plural first magnetic layers, a piezoelectric body provided on a opposite side to a side where the first electrode is provided in the laminated structure, and a third electrode applying voltage to the piezoelectric body and provided on a different position from a position where the first electrode is provided in the piezoelectric body.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: July 29, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Publication number: 20140139952
    Abstract: According to one embodiment, there is provided a thin magnetic film having a negative anisotropy of ?6×106 erg/cm3 or less and including, on at least a nonmagnetic substrate, at least one seed layer made of a metal or metal compound, a ruthenium underlayer for controlling the orientation of an immediately overlying layer, and a magnetic layer having negative anisotropy in the normal line direction perpendicular to a surface of the magnetic layer and mainly containing Co and Ir, wherein the additive element concentration of Ir in the magnetic layer is 10 (inclusive) to 45 (inclusive) at %.
    Type: Application
    Filed: July 19, 2013
    Publication date: May 22, 2014
    Inventors: Akihiko Takeo, Akira Kikitsu, Tomoyuki Maeda, Migaku Takahashi, Shin Saito, Ken Inoue, Gohei Kurokawa
  • Publication number: 20140104997
    Abstract: A magnetic recording medium is disclosed in which, on a non-magnetic substrate 1, at least an orientation control layer that controls orientation of a layer immediately above and a vertical magnetic layer in which an easy axis of magnetization is mainly vertically oriented with respect to the non-magnetic substrate are laminated. The orientation control layer includes an Ru-containing layer containing Ru or Ru alloy, and a diffusion prevention layer provided on the Ru-containing layer on the side of the vertical magnetic layer, is made of a material having a melting point of 1500° C. or higher and 4215° C. or lower and formed by a covalent bond or an ionic bond, and prevents thermal diffusion of Ru atoms of the Ru-containing layer.
    Type: Application
    Filed: October 10, 2013
    Publication date: April 17, 2014
    Applicants: SHOWA DENKO K.K., TOHOKU UNIVERSITY, KABUSHIKI KAISHA TOSHIBA
    Inventors: Hisato SHIBATA, Ken INOUE, Tsubasa OKADA, Gohei KUROKAWA, Shin SAITO, Shintaro HINATA, Migaku TAKAHASHI, Tomoyuki MAEDA, Yosuke ISOWAKI, Akira KIKITSU
  • Publication number: 20140097152
    Abstract: A self-assembled pattern forming method in an embodiment includes: forming a guide pattern on a substrate; forming a layer of a first polymer; filling a first block copolymer; and phase-separating the first block copolymer. The guide pattern includes a first recessed part having a depth T and a diameter D smaller than the depth T, and a second recessed part having a width larger than double of the diameter D. The first block copolymer has the first polymer and a second polymer which are substantially the same in volume fraction. By phase-separating the first block copolymer, a cylinder structure and a lamellar structure are obtained.
    Type: Application
    Filed: June 28, 2013
    Publication date: April 10, 2014
    Inventors: Hiroyuki HIEDA, Yoshiyuki KAMATA, Naoko KIHARA, Akira KIKITSU, Ryosuke YAMAMOTO
  • Patent number: 8681454
    Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: March 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Kikitsu, Yoshiyuki Kamata, Masatoshi Sakurai
  • Publication number: 20140078807
    Abstract: An example magnetic recording device includes a magnetic recording section and a magnetization oscillator and a first nonmagnetic layer disposed between the magnetic recording section and the magnetization oscillator. The magnetic recording section includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; and a second nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization oscillator includes a third ferromagnetic layer with a variable magnetization direction; a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction; and a third nonmagnetic layer disposed between the third ferromagnetic layer and the fourth ferromagnetic layer.
    Type: Application
    Filed: November 12, 2013
    Publication date: March 20, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shiho NAKAMURA, Hirofumi MORISE, Satoshi YANAGI, Daisuke SAIDA, Akira KIKITSU
  • Publication number: 20140030554
    Abstract: In one embodiment, there are provided: a substrate; a data area disposed on the substrate and having a plurality of first magnetic dots arrayed in lines in mutually different first, second, and third directions; and a boundary magnetic part having a plurality of first magnetic portions arrayed in a line in the third direction and each having a length longer than that of the first magnetic dot in the third direction, and a second magnetic dot disposed between the first magnetic portions and disposed on extensions in the first and second directions of the first magnetic dots, and disposed along with the data area on the substrate.
    Type: Application
    Filed: June 7, 2013
    Publication date: January 30, 2014
    Inventors: Akira KIKITSU, Naoko KIHARA, Yoshiyuki KAMATA, Hiroyuki HIEDA
  • Patent number: 8625335
    Abstract: A magnetic storage element according to an embodiment includes: a magnetic thin wire extending in a first direction and having a plurality of magnetic domains partitioned by domain walls; an electrode capable of applying a current flowing in the first direction and a current flowing in the opposite direction from the first direction, to the magnetic thin wire; and an assisting unit receiving an electrical input and assisting movement of the domain walls in an entire or part of the magnetic thin wire.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: January 7, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Patent number: 8611142
    Abstract: An example magnetic recording device includes a laminated body. The laminated body includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer with a variable magnetization direction; and a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction, wherein at least one of the first and second direction is generally perpendicular to the film plane. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by passing the current in a direction generally perpendicular to the film plane of the layers of the laminated body and the magnetization of the third ferromagnetic layer is able to undergo precession by passing the current.
    Type: Grant
    Filed: November 17, 2011
    Date of Patent: December 17, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida, Akira Kikitsu
  • Publication number: 20130250668
    Abstract: According to one embodiment, a magnetic memory element includes: a magnetic wire, a stress application unit, and a recording/reproducing unit. The magnetic wire includes a plurality of domain walls and a plurality of magnetic domains separated by the domain walls. The magnetic wire is a closed loop. The stress application unit is configured to cause the domain walls to circle around along the closed loop a plurality of times by applying stress to the magnetic wire. The recording/reproducing unit is configured to write memory information by changing magnetizations of the circling magnetic domains as the domain walls circle around and to read the written memory information by detecting the magnetizations of the circling magnetic domains.
    Type: Application
    Filed: February 4, 2013
    Publication date: September 26, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki FUKUZAWA, Yoshiaki Fukuzumi, Hirofumi Morise, Akira Kikitsu
  • Patent number: 8487345
    Abstract: According to one embodiment, an information recording and reproducing device includes a stacked body. The stacked body includes a first layer, a second layer and a recording layer provided between the first layer and the second layer. The recording layer includes a phase-change material and a crystal nucleus. The phase-change material is capable of reversely changing between a crystal state and an amorphous state by a current supplied via the first layer and the second layer. The crystal nucleus is provided in contact with the phase-change material and includes a crystal nucleus material having a crystal structure identical to a crystal structure of the crystal state of the phase-change material, and a crystal nucleus coating provided on a surface of the crystal nucleus material and having a composition different from a composition of the crystal nucleus material.
    Type: Grant
    Filed: September 20, 2010
    Date of Patent: July 16, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Tsukamoto, Tsukasa Nakai, Akira Kikitsu, Takeshi Yamaguchi, Sumio Ashida
  • Patent number: 8298690
    Abstract: A magnetic recording medium includes a disk substrate, and recording cells arrayed on the disk substrate in a track direction, the recording cells includes a ferromagnetic pattern and a magnetic pattern formed on one of two sidewalls of the ferromagnetic pattern in the track direction and having a lower crystalline magnetic anisotropy constant Ku than that of the ferromagnetic pattern.
    Type: Grant
    Filed: November 20, 2008
    Date of Patent: October 30, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Hieda, Kazuto Kashiwagi, Akira Kikitsu, Yousuke Isowaki, Yoshiyuki Kamata
  • Patent number: 8289645
    Abstract: According to one embodiment, there is provided a magnetic disk apparatus having a magnetic disk having magnetic dot lines each including magnetic dots arrayed at equal intervals in a down track direction, and a read/write head which uses a plurality of adjacent magnetic dot lines as one track and sequentially performs read and write on the magnetic dots included in the magnetic dot lines constituting the track, in which the magnetic dots included in each of the magnetic dot lines in each track of the magnetic disk are displaced in the down track direction from the magnetic dots included in the adjacent dot line in the track depending on a possible skew angle between the read/write head and the track so that the magnetic dots are sequentially accessed by the read/write head.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: October 16, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Akira Kikitsu, Kazuto Kashiwagi
  • Publication number: 20120250398
    Abstract: A magnetic storage element according to an embodiment includes: a magnetic thin wire extending in a first direction and having a plurality of magnetic domains partitioned by domain walls; an electrode capable of applying a current flowing in the first direction and a current flowing in the opposite direction from the first direction, to the magnetic thin wire; and an assisting unit receiving an electrical input and assisting movement of the domain walls in an entire or part of the magnetic thin wire.
    Type: Application
    Filed: September 21, 2011
    Publication date: October 4, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi
  • Publication number: 20120250406
    Abstract: A magnetic memory device comprises a first electrode, a second electrode, a laminated structure comprising plural first magnetic layers being provided between the first electrode and the second electrode, a second magnetic layer comprising different composition elements from that of the first magnetic layer and being provided between plural first magnetic layers, a piezoelectric body provided on a opposite side to a side where the first electrode is provided in the laminated structure, and a third electrode applying voltage to the piezoelectric body and provided on a different position from a position where the first electrode is provided in the piezoelectric body.
    Type: Application
    Filed: October 27, 2011
    Publication date: October 4, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hirofumi Morise, Hideaki Fukuzawa, Akira Kikitsu, Yoshiaki Fukuzumi