Patents by Inventor Yoshinori Tokura

Yoshinori Tokura 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: 9859017
    Abstract: To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.
    Type: Grant
    Filed: March 5, 2017
    Date of Patent: January 2, 2018
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9824712
    Abstract: A magnetic storage media which has an endurance (durability) characteristics close to an infinite number of writing times of data and a data retention (holding) characteristics close to permanency, and is ultra-high-speed writable and erasable, and a data storage device and an image storage device which apply this magnetic storage media are provided. A magnetic storage media includes a thin layer magnet and a magnetic field generating unit arranged facing a surface of the magnet, and is capable of creating or eliminating a skyrmion by applying heat energy to another surface of the magnet positioned on the opposite side of the surface of the magnet, and a skyrmion memory includes the magnetic storage media.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: November 21, 2017
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9748000
    Abstract: Provided is a skyrmion memory circuit capable of circularly transferring a magnetic element skyrmion, comprising one or more current paths in a magnet having a closed-path pattern that are provided surrounding an end region including an end portion of the magnet in a plane of the magnet with the closed-path pattern, and applying current between an outer terminal connected to an outer circumferential portion of the closed-path pattern and an inner circumference electrode connected to an inner circumferential portion of the closed-path pattern, transferring the skyrmion in a direction substantially perpendicular to the direction of the applied current, and circulating the skyrmion in the magnet with the closed-path pattern.
    Type: Grant
    Filed: December 28, 2016
    Date of Patent: August 29, 2017
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Publication number: 20170206921
    Abstract: A magnetic storage media which has an endurance (durability) characteristics close to an infinite number of writing times of data and a data retention (holding) characteristics close to permanency, and is ultra-high-speed writable and erasable, and a data storage device and an image storage device which apply this magnetic storage media are provided. A magnetic storage media includes a thin layer magnet and a magnetic field generating unit arranged facing a surface of the magnet, and is capable of creating or eliminating a skyrmion by applying heat energy to another surface of the magnet positioned on the opposite side of the surface of the magnet, and a skyrmion memory includes the magnetic storage media.
    Type: Application
    Filed: February 3, 2017
    Publication date: July 20, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Patent number: 9704550
    Abstract: To provide a magnetic element that controls generation and annihilation of a skyrmion. A magnetic element is provided, and the magnetic element comprises: a magnetic body that has a spiral magnetic structure in a stable state; a skyrmion control unit that generates skyrmion in the magnetic body by supplying energy to the magnetic body that has the spiral magnetic structure. Also, the magnetic element in which the skyrmion control unit brings the magnetic body into an unstable state by supplying thermal energy pulses to the magnetic body is provided. Furthermore, a skyrmion memory comprising the magnetic element is provided.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: July 11, 2017
    Assignee: RIKEN
    Inventors: Hiroshi Oike, Fumitaka Kagawa, Yoshinori Tokura
  • Publication number: 20170178747
    Abstract: To provide a magnetic element which can generate a skyrmion, and a skyrmion memory which applies the magnetic element or the like. To provide a magnetic element with a chiral magnet for generating a skyrmion, the chiral magnet is made of a magnetic material having a ?-Mn type crystal structure. Also, to provide a magnetic element with a chiral magnet for generating a skyrmion, the chiral magnet is made of a magnetic material having an Au4Al type crystal structure.
    Type: Application
    Filed: March 5, 2017
    Publication date: June 22, 2017
    Inventors: Yusuke TOKUNAGA, Xiuzhen YU, Yasujiro TAGUCHI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170178746
    Abstract: To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.
    Type: Application
    Filed: March 5, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170178748
    Abstract: A magnetic element capable of generating and erasing a skyrmion, including a magnet shaped as a thin layer and including a structure surrounded by a nonmagnetic material; a current path provided surrounding an end region including an end portion of the magnet, on one surface of the magnet; and a skyrmion sensor that detects the generation and erasing of the skyrmion. With Wm being width of the magnet and hm being height of the magnet, a size of the magnet, with the skyrmion of a diameter ? being generated, is such that 2?>Wm>?/2 and 2?>hm>?/2. With W being width of the end region in a direction parallel to the end portion of the magnet and h being height of the end region in a direction perpendicular to the end portion of the magnet, the end region is such that ??W>?/4 and 2?>h>?/2.
    Type: Application
    Filed: March 1, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170179376
    Abstract: Provided is a magnetic element which can generate a skyrmion by a stacked film including a magnetic layer and a non-magnetic layer, and a skyrmion memory to which the magnetic element is applied and the like. Provided is a magnetic element for generating a skyrmion, the magnetic element comprising a two-dimensional stacked film, wherein the two-dimensional stacked film is at least one or more multiple layered films including a magnetic film and a non-magnetic film stacked on the magnetic film. Also, provided is a skyrmion memory including a plurality of the magnetic elements stacked in a thickness direction.
    Type: Application
    Filed: March 6, 2017
    Publication date: June 22, 2017
    Inventors: Masao NAKAMURA, Jobu MATSUNO, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170179375
    Abstract: Provided is a magnetic element capable of generating one skyrmion and erasing the one skyrmion. The magnetic element includes a magnet shaped like a substantially rectangular flat plate, an upstream electrode connected to the magnet in a width Wm direction of the magnet and made of a non-magnetic metal, a downstream electrode connected to the magnet in the width Wm direction to oppose the upstream electrode and made of a non-magnetic metal, and a skyrmion sensor configured to detect the skyrmion. Here, a width Wm of the substantially rectangular magnet is such that 3·?>Wm??, where ? denotes a diameter of the skyrmion, a length Hm of the substantially rectangular magnet is such that 2·?>Hm??, and the magnet has a notch structure at the edge between the upstream electrode and the downstream electrode.
    Type: Application
    Filed: March 3, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170169898
    Abstract: Provided is a skyrmion memory circuit capable of circularly transferring a magnetic element skyrmion, comprising one or more current paths in a magnet having a closed-path pattern that are provided surrounding an end region including an end portion of the magnet in a plane of the magnet with the closed-path pattern, and applying current between an outer terminal connected to an outer circumferential portion of the closed-path pattern and an inner circumference electrode connected to an inner circumferential portion of the closed-path pattern, transferring the skyrmion in a direction substantially perpendicular to the direction of the applied current, and circulating the skyrmion in the magnet with the closed-path pattern.
    Type: Application
    Filed: December 28, 2016
    Publication date: June 15, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170053686
    Abstract: To provide a magnetic element that controls generation and annihilation of a skyrmion. A magnetic element is provided, and the magnetic element comprises: a magnetic body that has a spiral magnetic structure in a stable state; a skyrmion control unit that generates skyrmion in the magnetic body by supplying energy to the magnetic body that has the spiral magnetic structure. Also, the magnetic element in which the skyrmion control unit brings the magnetic body into an unstable state by supplying thermal energy pulses to the magnetic body is provided. Furthermore, a skyrmion memory comprising the magnetic element is provided.
    Type: Application
    Filed: May 31, 2016
    Publication date: February 23, 2017
    Inventors: Hiroshi OIKE, Fumitaka KAGAWA, Yoshinori TOKURA
  • Publication number: 20160343481
    Abstract: Control of electrical conductivity is provided via electrically conductive magnetic domain walls between magnetic domains. The magnetic domains are identical except for their magnetic configuration. Altering a configuration of the magnetic domains (e.g., by thermal treatment, application of a magnetic field, etc.) can alter the electrical resistance of a device. Such devices can be used as non-volatile information storage devices or as sensors.
    Type: Application
    Filed: May 20, 2016
    Publication date: November 24, 2016
    Inventors: Yue Ma, Yongtao Cui, Kentaro Ueda, Jun Fujioka, Yoshinori Tokura, Zhixun Shen, Robert B. Laughlin
  • Publication number: 20160223413
    Abstract: The stress sensor includes: a magnetic material; a stress applied portion on the magnetic material; a magnet disposed so as to be adjacent to by a magnetic material; a magnetic sensor disposed via the magnetic material so as to be opposed to the stress applied portion, wherein the magnetic sensor detects a magnetic flux emitted from a magnetic domain generated in the magnetic material by a local stress applied to the stress applied portion. The local stress or stress distribution can be detected with a convenience structure, and can obtain a high spatial resolution by using a stress response phenomenon of a single magnetic domain.
    Type: Application
    Filed: December 30, 2015
    Publication date: August 4, 2016
    Inventors: Masashi KUBOTA, Masashi KAWASAKI, Yoshinori TOKURA
  • Publication number: 20110253204
    Abstract: A solar cell 1 has a p-n junction structure between a first solid material layer 3 comprising an insulator or a semiconductor and a second solid material layer 5 comprising an insulator or a semiconductor of a type different from the type of the first solid material layer 3, in which structure a Mott insulator or a Mott semiconductor is used as a solid material of at least one of the layers.
    Type: Application
    Filed: April 7, 2011
    Publication date: October 20, 2011
    Inventors: Wataru Koshibae, Masao Nakamura, Masashi Kawasaki, Naoto Nagaosa, Yasujiro Taguchi, Yoshinori Tokura, Nobuo Furukawa
  • Patent number: 7978047
    Abstract: A variable resistance element comprises a variable resistor of strongly-correlated material sandwiched between two metal electrodes, and the electric resistance between the metal electrodes varies when a voltage pulse is applied between the metal electrodes. Such a switching operation as the ratio of electric resistance between low and high resistance states is high can be attained by designing the metal electrodes and variable resistor appropriately based on a definite switching operation principle. Material and composition of the first electrode and variable resistor are set such that metal insulator transition takes place on the interface of the first electrode in any one of two metal electrodes and the variable resistor by applying a voltage pulse. Two-phase coexisting phase of metal and insulator phases can be formed in the vicinity of the interface between the variable resistor and first electrode by the work function difference between the first electrode and variable resistor.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: July 12, 2011
    Assignees: Sharp Kabushiki Kaisha, National Science and Technology
    Inventors: Yasunari Hosoi, Shigeo Ohnishi, Yasushi Ogimoto, Takashi Oka, Naoto Nagaosa, Yoshinori Tokura
  • Patent number: 7932505
    Abstract: Provided is a material composition which allows a nonvolatile memory element made of a perovskite-type transition metal oxide having the CER effect to be formed of three elements, which comprises an electric conductor having a shallow work function or a small electronegativity, such as Ti, as an electrode and a rare earth-copper oxide comprising one type of rare earth element, copper and oxygen, such as La2CuO4, as a material constituting a heterojunction with the electric conductor.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: April 26, 2011
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Akihito Sawa, Takeshi Fujii, Masashi Kawasaki, Yoshinori Tokura
  • Patent number: 7715094
    Abstract: The present invention provides a rare earth element-doped optical fiber amplifier having a function which allows to omit an optical isolator component, and a method for providing the optical non-reciprocity using the same. In the optical fiber, the optical fiber matrix material is a ferroelectric solid state material, and the ferroelectric solid state material is doped by a rare earth element such as erbium (Er) or thulium (Tm). The optical fiber is characterized by an optical amplification function and an optical non-reciprocity function.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: May 11, 2010
    Assignees: Japan Science of Technology Agency, National Institute of Advanced Industrial Science and Technology
    Inventors: Yoshinori Tokura, Yoshiaki Shimada, Yoshio Kaneko
  • Patent number: 7633723
    Abstract: To provide a tunnel junction device having a high MR ratio even at room temperature, a tunneling film as a nonmagnetic layer of three-layer structure of LaMnO3/SrTiO3/LaMnO3 is arranged between a ferromagnetic metal material La0.6Sr0.4MnO3 (12) and a ferromagnetic metal film material La0.6Sr0.4MnO3 (14). The tunneling film comprises two unit layers of LaMnO3 (13A) arranged on the ferromagnetic metal material La0.6Sr0.4MnO3 (12); five unit layers of SrTiO3 (13B); and two unit layers of LaMnO3 (13C) arranged at the interface between the SrTiO3 (13B) and the ferromagnetic metal film material La0.6Sr0.4MnO3 (14).
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: December 15, 2009
    Assignees: National Institute of Advanced Industrial Science and Technology, Japan Science and Technology Agency
    Inventors: Yoshinori Tokura, Masashi Kawasaki, Hiroyuki Yamada, Yoshihiro Ogawa, Yoshio Kaneko
  • Publication number: 20090231083
    Abstract: A variable resistance element comprises a variable resistor of strongly-correlated material sandwiched between two metal electrodes, and the electric resistance between the metal electrodes varies when a voltage pulse is applied between the metal electrodes. Such a switching operation as the ratio of electric resistance between low and high resistance states is high can be attained by designing the metal electrodes and variable resistor appropriately based on a definite switching operation principle. Material and composition of the first electrode and variable resistor are set such that metal insulator transition takes place on the interface of the first electrode in any one of two metal electrodes and the variable resistor by applying a voltage pulse. Two-phase coexisting phase of metal and insulator phases can be formed in the vicinity of the interface between the variable resistor and first electrode by the work function difference between the first electrode and variable resistor.
    Type: Application
    Filed: August 8, 2006
    Publication date: September 17, 2009
    Inventors: Yasunari Hosoi, Shigeo Ohnishi, Yasushi Ogimoto, Takashi Oka, Naoto Nagaosa, Yoshinori Tokura