Patents by Inventor Atsufumi Hirohata
Atsufumi Hirohata 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).
-
Publication number: 20180158962Abstract: A pulse generation device includes a substrate, a spin injector provided on the substrate and made of a ferromagnetic body, a spin rotor provided on the substrate, made of a ferromagnetic body, and having magnetic anisotropy in which a direction of a first axis becomes an easy axis of magnetization, a channel portion made of a nonmagnetic body, and joined with the spin injector and the spin rotor directly or via an insulating layer, and a generating portion configured to generate a pulse by detecting, when a magnetic moment of the spin rotor is reversed from a state in which the magnetic moment faces one side of the first axis to a state in which the magnetic moment faces the other side of the first axis, a state in which the magnetic moment of the spin rotor faces a direction along a second axis orthogonal to the first axis.Type: ApplicationFiled: May 20, 2016Publication date: June 7, 2018Applicants: JAPAN SCIENCE AND TECHNOLOGY AGENCY, THE UNIVERSITY OF YORKInventor: Atsufumi HIROHATA
-
Patent number: 9882118Abstract: A spin control mechanism includes a spin portion and a first channel portion. The spin portion has a magnetic moment that can be reversed and rotated. The first channel portion is provided in contact with the spin portion, and is configured from ferromagnetic insulator. Then, the spin control mechanism controls a direction of the magnetic moment of the spin portion using a spin current generated by a temperature gradient provided to the first channel portion.Type: GrantFiled: October 29, 2014Date of Patent: January 30, 2018Assignees: JAPAN SCIENCE AND TECHNOLOGY AGENCY, THE UNIVERSITY OF YORKInventor: Atsufumi Hirohata
-
Patent number: 9553256Abstract: A spin valve element 10 including a spin injector 12 made of a ferromagnetic material, a spin detector 16 made of a ferromagnetic material, and a channel part 14 made of a non-magnetic material. The spin detector 16 is arranged at a position separated from the spin injector 12, the channel part 14 is connected with the spin injector 12 and the spin detector 16 directly or through an insulating layer, and a plurality of spin diffusion portions 30 to 34 with enlarged cross section areas in a direction perpendicular to a spin current is formed in the channel part 14.Type: GrantFiled: October 31, 2013Date of Patent: January 24, 2017Assignees: Japan Science and Technology Agency, The University of YorkInventor: Atsufumi Hirohata
-
Patent number: 9548634Abstract: A spin rotary member includes a substrate, a spin injector made of a ferromagnetic material magnetized in a substrate in-plane direction, and provided on the substrate, a spin rotor made of a ferromagnetic material having a magnetic moment rotatable in the substrate in-plane direction, and provided on the substrate, being separated from the spin injector, a channel part made of a non-magnetic material, arranged between the spin injector and the spin rotor, and bonded with the spin injector and the spin rotor directly or through an insulating layer, and a spin rotation control part configured to control a rotation direction of spin of the channel part.Type: GrantFiled: July 25, 2013Date of Patent: January 17, 2017Assignees: Japan Science and Technology Agency, The University of YorkInventor: Atsufumi Hirohata
-
Publication number: 20160359104Abstract: A crystallisation method for an alloy film such as a Co-based ternary Heusler-alloy is described having the steps of: providing a substrate; depositing a layer of the alloy film to be crystallised onto the substrate using a physical vapour deposition process to a depth of up to a few hundred nm; optionally depositing a capping layer thereon; heating the deposited film at an annealing temperature below 300° C. and for example of around 200° C. to 300° C. to effect crystallisation of the alloy film layer. The method is in particular applied to the in the deposition and annealing in situ of an alloy film in or on a semiconductor device for example as a functional film in or on such a device and in particular to the deposition and annealing in situ of a highly-spin-polarised ferromagnetic thin film on a semiconductor or spintronic device.Type: ApplicationFiled: February 12, 2015Publication date: December 8, 2016Applicant: The University of YorkInventors: Luke Roger Fleet, Atsufumi Hirohata, James Thomas Sagar
-
Publication number: 20160268497Abstract: A spin control mechanism includes a spin portion and a first channel portion. The spin portion has a magnetic moment that can be reversed and rotated. The first channel portion is provided in contact with the spin portion, and is configured from ferromagnetic insulator. Then, the spin control mechanism controls a direction of the magnetic moment of the spin portion using a spin current generated by a temperature gradient provided to the first channel portion.Type: ApplicationFiled: October 29, 2014Publication date: September 15, 2016Applicants: JAPAN SCIENCE AND TECHNOLOGY AGENCY, The University of YorkInventor: Atsufumi HIROHATA
-
Patent number: 9293184Abstract: There is provided a method of pinning domain walls in a magnetic memory device (10) comprising using an antiferromagnetic material to create domain wall pinning sites. Junctions (22) where arrays of ferromagnetic nanowires (16) and antiferromagnetic nanowires (20) cross exhibit a permanent exchange bias interaction between the ferromagnetic material and the antiferromagnetic material which creates domain wall pinning sites. The exchange bias field is between 30 to 3600 Oe and the anisotropy direction of the ferromagnetic elements is between 15 to 75° to an anisotropy direction of the antiferromagnetic elements.Type: GrantFiled: October 8, 2012Date of Patent: March 22, 2016Assignee: University of YorkInventors: Kevin O'Grady, Gonzalo Vallejo Fernandez, Atsufumi Hirohata
-
Patent number: 9190500Abstract: There are provided with a source part made of a ferromagnetic material magnetized in a first direction, a drain part made of a ferromagnetic material magnetized in the first direction, and separated from and arranged in parallel to the source part, a channel part arranged between the source part and the drain part, and bonded with the source part and the drain part directly or through a tunnel layer, and a circularly polarized light irradiation part that irradiates the channel part with circularly polarized light for controlling a direction of spin of the channel part.Type: GrantFiled: July 25, 2013Date of Patent: November 17, 2015Assignees: Japan Science and Technology Agency, The University of YorkInventor: Atsufumi Hirohata
-
Publication number: 20150311428Abstract: A spin valve element 10 including a spin injector 12 made of a ferromagnetic material, a spin detector 16 made of a ferromagnetic material, and a channel part 14 made of a non-magnetic material. The spin detector 16 is arranged at a position separated from the spin injector 12, the channel part 14 is connected with the spin injector 12 and the spin detector 16 directly or through an insulating layer, and a plurality of spin diffusion portions 30 to 34 with enlarged cross section areas in a direction perpendicular to a spin current is formed in the channel part 14.Type: ApplicationFiled: October 31, 2013Publication date: October 29, 2015Applicant: Japan Science and Technology AgencyInventor: Atsufumi Hirohata
-
Publication number: 20150229169Abstract: A spin rotary member includes a substrate, a spin injector made of a ferromagnetic material magnetized in a substrate in-plane direction, and provided on the substrate, a spin rotor made of a ferromagnetic material having a magnetic moment rotatable in the substrate in-plane direction, and provided on the substrate, being separated from the spin injector, a channel part made of a non-magnetic material, arranged between the spin injector and the spin rotor, and bonded with the spin injector and the spin rotor directly or through an insulating layer, and a spin rotation control part configured to control a rotation direction of spin of the channel part.Type: ApplicationFiled: July 25, 2013Publication date: August 13, 2015Inventor: Atsufumi Hirohata
-
Publication number: 20150200282Abstract: There are provided with a source part made of a ferromagnetic material magnetized in a first direction, a drain part made of a ferromagnetic material magnetized in the first direction, and separated from and arranged in parallel to the source part, a channel part arranged between the source part and the drain part, and bonded with the source part and the drain part directly or through a tunnel layer, and a circularly polarized light irradiation part that irradiates the channel part with circularly polarized light for controlling a direction of spin of the channel part.Type: ApplicationFiled: July 25, 2013Publication date: July 16, 2015Applicant: Japan Science and Technology AgencyInventor: Atsufumi Hirohata