Patents by Inventor Tohru Oikawa
Tohru Oikawa 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: 11495735Abstract: A spin-current magnetization rotational element includes: a ferromagnetic metal layer; and a spin-orbit torque wiring that extends in a first direction intersecting a stacking direction of the ferromagnetic metal layer and is bonded to the ferromagnetic metal layer. A direction of a spin injected into the ferromagnetic metal layer from the spin-orbit torque wiring intersects a magnetization direction of the ferromagnetic metal layer. The ferromagnetic metal layer has shape anisotropy and has a demagnetizing field distribution caused by the shape anisotropy. The demagnetizing field distribution generates an easy magnetization rotational direction in which the magnetization of the ferromagnetic metal layer is most easily reversed. The easy magnetization rotational direction intersects the first direction in a plan view seen from the stacking direction.Type: GrantFiled: July 25, 2017Date of Patent: November 8, 2022Assignee: TDK CORPORATIONInventors: Tatsuo Shibata, Tomoyuki Sasaki, Tohru Oikawa
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Publication number: 20220158082Abstract: A method for producing a spin current magnetization rotational element includes a stacking step of stacking, on one surface of a substrate, a magnetoresistance effect element having a first ferromagnetic metal layer having a fixed magnetization direction, a second ferromagnetic metal layer having a variable magnetization direction, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a first direction, wherein an inclined surface non-parallel to the first direction is formed on at least a part of a surface of the spin-orbit torque wiring.Type: ApplicationFiled: November 15, 2021Publication date: May 19, 2022Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tatsuo SHIBATA, Tohru OIKAWA
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Patent number: 11211548Abstract: This spin current magnetization reversal element includes a magnetoresistance effect element having a first ferromagnetic metal layer having a fixed magnetization direction, a second ferromagnetic metal layer having a variable magnetization direction, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a first direction that intersects the stacking direction of the magnetoresistance effect element, and contacts the surface of the magnetoresistance elect element on the side facing the second ferromagnetic metal layer, wherein at least one surface of the second ferromagnetic metal layer in the stacking direction has an inclined surface that is inclined in the first direction, and the direction of magnetization of the second ferromagnetic metal layer is inclined due to the inclined surface.Type: GrantFiled: July 19, 2019Date of Patent: December 28, 2021Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tatsuo Shibata, Tohru Oikawa
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Patent number: 11107615Abstract: A magnetization rotational element includes a ferromagnetic metal layer, and a spin-orbit torque wiring extending in a first direction intersecting a lamination direction of the ferromagnetic metal layer and having the ferromagnetic metal layer positioned on one surface thereof, in which a direction of spin injected from the spin-orbit torque wiring into the ferromagnetic metal layer intersects a magnetization direction of the ferromagnetic metal layer, and a damping constant of the ferromagnetic metal layer is larger than 0.01.Type: GrantFiled: February 22, 2018Date of Patent: August 31, 2021Assignee: TDK CORPORATIONInventors: Tohru Oikawa, Tomoyuki Sasaki, Yohei Shiokawa, Tatsuo Shibata
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Patent number: 10892401Abstract: This spin current magnetization rotational element includes a second ferromagnetic metal layer 1 having a variable magnetization orientation, and spin-orbit torque wiring 2, which extends in a direction that intersects a direction perpendicular to the surface of the second ferromagnetic metal layer 1, and is connected to the second ferromagnetic metal layer 1, wherein the spin resistance of a connection portion of the spin-orbit torque wiring layer 2 that is connected to the second ferromagnetic metal layer 1 is larger than the spin resistance of the second ferromagnetic metal layer 1.Type: GrantFiled: September 18, 2019Date of Patent: January 12, 2021Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tohru Oikawa
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Publication number: 20200168383Abstract: A magnetization rotational element includes a ferromagnetic metal layer, and a spin-orbit torque wiring extending in a first direction intersecting a lamination direction of the ferromagnetic metal layer and having the ferromagnetic metal layer positioned on one surface thereof, in which a direction of spin injected from the spin-orbit torque wiring into the ferromagnetic metal layer intersects a magnetization direction of the ferromagnetic metal layer, and a damping constant of the ferromagnetic metal layer is larger than 0.01.Type: ApplicationFiled: February 22, 2018Publication date: May 28, 2020Applicant: TDK CORPORATIONInventors: Tohru OIKAWA, Tomoyuki SASAKI, Yohei SHIOKAWA, Tatsuo SHIBATA
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Patent number: 10636466Abstract: A spin current assisted magnetoresistance effect device includes: a spin current assisted magnetoresistance effect element including a magnetoresistance effect element part and a spin-orbit torque wiring; and a controller electrically connected to the spin current assisted magnetoresistance effect element. In a portion in which the magnetoresistance effect element part and the spin-orbit torque wiring are bonded, an STT inversion current flowing through the magnetoresistance effect element part and an SOT inversion current flowing through the spin-orbit torque wiring merge or are divided, and the controller is configured to be capable of performing control for applying the STT inversion current to the spin current assisted magnetoresistance effect element at the same time as an application of the SOT inversion current or a time application of the SOT inversion current.Type: GrantFiled: November 15, 2019Date of Patent: April 28, 2020Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tohru Oikawa
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Patent number: 10593867Abstract: A spin current magnetization rotational element includes: a first ferromagnetic metal layer having a variable magnetization direction; and a spin orbital torque wiring which is joined to the first ferromagnetic metal layer and extends in a direction crossing a direction perpendicular to a plane of the first ferromagnetic metal layer, wherein the spin orbital torque wiring is constituted of a non-magnetic material composed of elements of two or more kinds and a compositional proportion of the non-magnetic material has a non-uniform distribution between a first surface joined to the first ferromagnetic metal layer and a second surface located on a side opposite to the first surface.Type: GrantFiled: November 14, 2017Date of Patent: March 17, 2020Assignee: TDK CORPORATIONInventors: Yohei Shiokawa, Tomoyuki Sasaki, Tohru Oikawa
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Publication number: 20200082964Abstract: A composite magnetic body with high permeability and low magnetic loss in a high-frequency region of a gigahertz band; and a high-frequency electronic component using the same, the electronic component being compact and having low-insertion loss. This composite magnetic body has a high permeability and a low magnetic loss especially in a high-frequency region of a gigahertz band, and is provided with: a plurality of magnetic nanowires 361-363 aligned so as not to cross each other; and insulators 365-367 that electrically insulate the plurality of magnetic nanowires 361-363.Type: ApplicationFiled: March 30, 2018Publication date: March 12, 2020Applicant: TDK CORPORATIONInventors: Takeshi SAKAMOTO, Yoshihiro SHINKAI, Yu YONEZAWA, Hideharu MORO, Kensuke ARA, Tohru OIKAWA, Isao KANADA, Kenji HORINO, Kyung-Ku CHOI
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Publication number: 20200082861Abstract: A spin current assisted magnetoresistance effect device includes: a spin current assisted magnetoresistance effect element including a magnetoresistance effect element part and a spin-orbit torque wiring; and a controller electrically connected to the spin current assisted magnetoresistance effect element. In a portion in which the magnetoresistance effect element part and the spin-orbit torque wiring are bonded, an STT inversion current flowing through the magnetoresistance effect element part and an SOT inversion current flowing through the spin-orbit torque wiring merge or are divided, and the controller is configured to be capable of performing control for applying the STT inversion current to the spin current assisted magnetoresistance effect element at the same time as an application of the SOT inversion current or a time application of the SOT inversion current.Type: ApplicationFiled: November 15, 2019Publication date: March 12, 2020Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tohru OIKAWA
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Publication number: 20200035911Abstract: This spin current magnetization rotational element includes a second ferromagnetic metal layer 1 having a variable magnetization orientation, and spin-orbit torque wiring 2, which extends in a direction that intersects a direction perpendicular to the surface of the second ferromagnetic metal layer 1, and is connected to the second ferromagnetic metal layer 1, wherein the spin resistance of a connection portion of the spin-orbit torque wiring layer 2 that is connected to the second ferromagnetic metal layer 1 is larger than the spin resistance of the second ferromagnetic metal layer 1.Type: ApplicationFiled: September 18, 2019Publication date: January 30, 2020Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tohru OIKAWA
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Patent number: 10497417Abstract: A spin current assisted magnetoresistance effect device includes: a spin current assisted magnetoresistance effect element including a magnetoresistance effect element part and a spin-orbit torque wiring; and a controller electrically connected to the spin current assisted magnetoresistance effect element. In a portion in which the magnetoresistance effect element part and the spin-orbit torque wiring are bonded, an STT inversion current flowing through the magnetoresistance effect element part and an SOT inversion current flowing through the spin-orbit torque wiring merge or are divided, and the controller is configured to be capable of performing control for applying the STT inversion current to the spin current assisted magnetoresistance effect element at the same time as an application of the SOT inversion current or a time application of the SOT inversion current.Type: GrantFiled: May 22, 2017Date of Patent: December 3, 2019Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tohru Oikawa
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Patent number: 10490731Abstract: This spin current magnetization rotational element includes a second ferromagnetic metal layer having a variable magnetization orientation, and spin-orbit torque wiring, which extends in a direction that intersects a direction perpendicular to the surface of the second ferromagnetic metal layer, and is connected to the second ferromagnetic metal layer, wherein the spin resistance of a connection portion of the spin-orbit torque wiring that is connected to the second ferromagnetic metal layer is larger than the spin resistance of the second ferromagnetic metal layer.Type: GrantFiled: November 25, 2016Date of Patent: November 26, 2019Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tohru Oikawa
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Publication number: 20190348598Abstract: This spin current magnetization reversal element includes a magnetoresistance effect element having a first ferromagnetic metal layer having a fixed magnetization direction, a second ferromagnetic metal layer having a variable magnetization direction, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a first direction that intersects the stacking direction of the magnetoresistance effect element, and contacts the surface of the magnetoresistance elect element on the side facing the second ferromagnetic metal layer, wherein at least one surface of the second ferromagnetic metal layer in the stacking direction has an inclined surface that is inclined in the first direction, and the direction of magnetization of the second ferromagnetic metal layer is inclined due to the inclined surface.Type: ApplicationFiled: July 19, 2019Publication date: November 14, 2019Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tatsuo SHIBATA, Tohru OIKAWA
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Patent number: 10418545Abstract: This spin current magnetization reversal element includes a magnetoresistance effect element having a first ferromagnetic metal layer having a fixed magnetization direction, a second ferromagnetic metal layer having a variable magnetization direction, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a first direction that intersects the stacking direction of the magnetoresistance effect element, and contacts the surface of the magnetoresistance effect element on the side facing the second ferromagnetic metal layer, wherein at least one surface of the second ferromagnetic metal layer in the stacking direction has an inclined surface that is inclined in the first direction, and the direction of magnetization of the second ferromagnetic metal layer is inclined due to the inclined surface.Type: GrantFiled: July 5, 2017Date of Patent: September 17, 2019Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Tatsuo Shibata, Tohru Oikawa
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Publication number: 20190147929Abstract: A spin current assisted magnetoresistance effect device includes: a spin current assisted magnetoresistance effect element including a magnetoresistance effect element part and a spin-orbit torque wiring; and a controller electrically connected to the spin current assisted magnetoresistance effect element. In a portion in which the magnetoresistance effect element part and the spin-orbit torque wiring are bonded, an STT inversion current flowing through the magnetoresistance effect element part and an SOT inversion current flowing through the spin-orbit torque wiring merge or are divided, and the controller is configured to be capable of performing control for applying the STT inversion current to the spin current assisted magnetoresistance effect element at the same time as an application of the SOT inversion current or a time application of the SOT inversion current.Type: ApplicationFiled: May 22, 2017Publication date: May 16, 2019Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tohru OIKAWA
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Publication number: 20190058111Abstract: A spin-current magnetization rotational element includes: a ferromagnetic metal layer; and a spin-orbit torque wiring that extends in a first direction intersecting a stacking direction of the ferromagnetic metal layer and is bonded to the ferromagnetic metal layer. A direction of a spin injected into the ferromagnetic metal layer from the spin-orbit torque wiring intersects a magnetization direction of the ferromagnetic metal layer. The ferromagnetic metal layer has shape anisotropy and has a demagnetizing field distribution caused by the shape anisotropy. The demagnetizing field distribution generates an easy magnetization rotational direction in which the magnetization of the ferromagnetic metal layer is most easily reversed. The easy magnetization rotational direction intersects the first direction in a plan view seen from the stacking direction.Type: ApplicationFiled: July 25, 2017Publication date: February 21, 2019Applicant: TDK CORPORATIONInventors: Tatsuo SHIBATA, Tomoyuki SASAKI, Tohru OIKAWA
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Publication number: 20190051816Abstract: A spin current magnetization rotational element includes: a first ferromagnetic metal layer having a variable magnetization direction; and a spin orbital torque wiring which is joined to the first ferromagnetic metal layer and extends in a direction crossing a direction perpendicular to a plane of the first ferromagnetic metal layer, wherein the spin orbital torque wiring is constituted of a non-magnetic material composed of elements of two or more kinds and a compositional proportion of the non-magnetic material has a non-uniform distribution between a first surface joined to the first ferromagnetic metal layer and a second surface located on a side opposite to the first surface.Type: ApplicationFiled: November 14, 2017Publication date: February 14, 2019Applicant: TDK CORPORATIONInventors: Yohei SHIOKAWA, Tomoyuki SASAKI, Tohru OIKAWA
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Patent number: 10193061Abstract: A spin-orbit torque magnetization rotational element includes: a ferromagnetic metal layer, a magnetization direction of which is configured to be changed; a spin-orbit torque wiring bonded to the ferromagnetic metal layer; and an interfacial distortion supply layer bonded to a surface of the spin-orbit torque wiring on a side opposite to the ferromagnetic metal layer.Type: GrantFiled: October 25, 2017Date of Patent: January 29, 2019Assignee: TDK CORPORATIONInventors: Yohei Shiokawa, Tomoyuki Sasaki, Tohru Oikawa
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Publication number: 20180351082Abstract: This spin current magnetization rotational element includes a second ferromagnetic metal layer having a variable magnetization orientation, and spin-orbit torque wiring, which extends in a direction that intersects a direction perpendicular to the surface of the second ferromagnetic metal layer, and is connected to the second ferromagnetic metal layer, wherein the spin resistance of a connection portion of the spin-orbit torque wiring that is connected to the second ferromagnetic metal layer is larger than the spin resistance of the second ferromagnetic metal layer.Type: ApplicationFiled: November 25, 2016Publication date: December 6, 2018Applicant: TDK CORPORATIONInventors: Tomoyuki SASAKI, Tohru OIKAWA