Tdk Corporation

Other

Jiro Yoshinari

Tetsuro Mizushima

Takuya Tsukagoshi

Hideaki Miura

Naoki Hayashida

Shinji Miyazaki

Hiroyasu Inoue

Hiroshi Shingai

Atsuko Kosuda

Tomoyuki Sasaki

Yohei Shiokawa

Masanori Kosuda

Tatsuya Kato

Koji Mishima

Koji Kobayashi

Haruyuki Morita

Yasumichi Tokuoka

Kazumasa Fukuda

Kazushi Tanaka

Tsuyoshi Komaki

Motohiro Inoue

Shohei Fujii

Mori Nagayama

Takashi Kikukawa

Hideki Hirata

Lambertus Hesselink

Mark E McDonald

Masatoshi Nakayama

Andrew J Daiber

Michael V Morelli

Mitsuru Takai

Sergei L Sochava

Noriyuki Kawano

Masaki Aoshima

Isamu Kuribayashi

Yuichi Sato

Hironori Kakiuchi

Hiroshi Chihara

Tokuyuki Honda

Rie Ihara

Sanjoy Ghose

Shunichi Nishimura

Hideki Sunohara

A spin current magnetization reversing element () includes a spin orbit torque wiring layer () that extends in one direction, a first ferromagnetic layer () that is formed on a first surface () of the spin orbit torque wiring layer, and a first insulating layer () that is formed on a second surface () on a side opposite to the first ferromagnetic layer () side on the surface of the spin orbit torque wiring layer. The first insulating layer () contains boron nitride or aluminum nitride.

Spin current magnetization reversing element, magnetoresistance effect element, magnetic memory, and magnetic device

A magnetoresistance effect element has a structure in which a first ferromagnetic layer, a non-magnetic layer, and a second ferromagnetic layer are subsequently laminated and outer circumferential portions of the first ferromagnetic layer, the non-magnetic layer, and the second ferromagnetic layer are covered with a first insulating film which contains silicon nitride as a main component and contains further boron nitride or aluminum nitride.

Magnetoresistance effect element, magnetic memory, and magnetic device

A random number generator capable of generating a natural random number using a spin-orbit torque (SOT) is provided. The random number generator includes a ferromagnetic metal layer and a spin-orbit torque wiring extending in a first direction crossing a lamination direction of the ferromagnetic metal layer and being joined to the ferromagnetic metal layer, wherein the direction of spins injected from the spin-orbit torque wiring into the ferromagnetic metal layer and an easy magnetization direction of the ferromagnetic metal layer intersect each other.

Random number generator, random number generation device, neuromorphic computer, and quantum computer

A hologram recording material includes a polymerizable monomer (A) that is active in radical polymerization but is substantially inactive in cationic polymerization, a polymerizable monomer (B) that is active in cationic polymerization but is substantially inactive in radical polymerization, and an initiator system (C) that polymerizes at least one of the polymerizable monomer (A) and the polymerizable monomer (B) through irradiation with light. The polymerizable monomer (A) and the polymerizable monomer (B) each have, in its structure, a moiety selected from the group consisting of aromatic rings, halogen atoms other than a fluorine atom, and sulfur atoms not derived from a cyclic sulfide or a mercapto group. A hologram recording medium includes a recording layer composed of the hologram recording material.

Hologram recording material and hologram recording medium

The present invention provides a hologram recording material and a hologram recording medium, which are suitable for volume hologram record and can attain high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, that is, storage stability, durability, low dimensional change (low shrinkage) and high multiplicity in holographic memory recording using not only a green laser but also a blue laser. A hologram recording material comprising: a radical photopolymerizable compound; and a matrix which is a dispersion medium for the radical photopolymerizable compound, wherein the radical photopolymerizable compound comprises a (meth)acrylamide derivative represented by the following general formula (I): CH&#x2550;CR&#x2014;CONR&#x2014;CH&#x2014;O&#x2014;R(I) wherein Rrepresents H or a CHgroup, Rrepresents H or an organic group, and Rrepresents an organic group having 3 or more carbon atoms in total. A hologram recording mediumwhich has a hologram recording layer

The present invention provides a hologram recording material and a hologram recording medium that can stably maintain the shape of a recording layer and achieve high diffraction efficiency. A hologram recording material comprising a photoradical polymerizable compound (A), a photopolymerization initiator (B), and a dispersion medium (C). The medium (C) is selected from the group consisting of: a compound of the formula (I): wherein Ris a divalent Chydrocarbon group, Rand Reach independently represent a Chydrocarbon group, k, l, m and n are each independently a number of 0 or more and 5 or less; and a compound of the formula (II): wherein Rrepresents a divalent Chydrocarbon group, Rand Reach independently represent a Chydrocarbon group, and at least one of Rand Rrepresents a Chydrocarbon group.

An optimal recording exposure is determined by varying in the first to nth stages the recording exposure with a write laser beam to record a bright pattern image and a dark pattern image in each stage as the first to nth bright pattern images and the first to nth dark pattern images, respectively; irradiating the respective pattern images with a read beam to detect the intensity of a diffracted beam from the central portion of each image of the bright and dark patterns; calculating Sa/Sb=SNR, . . . , and Sa/Sb=SNR, where Sato Saare the intensity of a diffracted beam from the first to nth bright pattern images and Sbto Sb, are the intensity of s diffracted beam from the first to nth dark pattern images; and determining a recording exposure which is given at the SNRbeing the maximum value of the resulting SNRto SNR.

Method for determining recording exposure for holographic recording medium and method for recording thereon

The present invention provides a hologram recording material which is suitable for volume hologram record and attains high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low shrinkage and high multiplicity in holographic memory record using not only a green laser but also a blue laser; a process for producing the same; and a hologram recording medium having the hologram recording material. A hologram recording material comprising: a metal oxide comprising Si and at least one selected from the group consisting of Ta and Zr, as metals, wherein a complexing ligand is coordinated to Ta and/or Zr; and a photopolymerizable compound. The complexing ligand is preferably selected from the group consisting of &#x3b2;-dicarbonyl compounds, polyhydroxylated ligands, and &#x3b1;- or &#x3b2;-hydroxy acids. A hologram recording medium () comprising the hologram recording material layer ().

Hologram recording material, process for producing the same and hologram recording medium

The present invention provides a hologram recording medium which can attain high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low dimension change (low shrinkage) and high multiplicity in holographic memory record using a blue laser. A hologram recording medium () comprising at least a hologram recording material layer, wherein the hologram recording material layer () comprises at least a metal oxide and a photopolymerizable compound; and said hologram recording medium has a light transmittance of 50% or more at a wavelength of 405 nm, or a light reflectance of 25% or more at a wavelength of 405 nm.

Hologram recording medium

A recording and reading system for a multi-layered optical recording medium includes: a multi-layered optical recording medium including a plurality of recording layers and a single servo layer; and an optical head. The optical head includes a recording and reading objective lens of a signal recording and reading optical system and a servo objective lens of a servo signal detection optical system that are disposed on a common actuator. The recording and reading objective lens is mounted on the common actuator through a minute-drive apparatus so as to be minutely driven in a focusing direction relative to the servo objective lens. When the servo objective lens is focused on the servo layer, a reading light beam is quickly focused on a target one of the plurality of recording layers.

Optical head device and reading system for multi-layered optical recording medium

The present invention provides a hologram recording material which attains high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low shrinkage, and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising: an organometallic compound at least containing at least two kinds of metals, oxygen, and an aromatic group, and having an organometallic unit wherein two aromatic groups are bonded directly to one metal; and a photopolymerizable compound containing at least a monofunctional compound (A) having one polymerizable functional group in the molecule. The hologram recording material may comprise, as the photopolymerizable compound, a polyfunctional compound (B) having two or more polymerizable functional groups in the molecule. A hologram recording mediumhas a hologram recording material layer

Hologram recording material, and hologram recording medium

The present invention provides a hologram recording material which attains high refractive index change, high flexibility, high sensitivity, low scattering, environment resistance, durability, low dimensional change and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising: an organometallic compound at least containing at least two kinds of metals, oxygen, and an aromatic group and having an organometallic unit wherein two aromatic groups are bonded directly to one metal; and a photopolymerizable compound. One of the at least two kinds of metals is Si, and the metal(s) other than Si is/are preferably selected from the group consisting of Ti, Zr, Ge, Sn, Al and Zn. The organometallic unit is preferably a unit wherein two aromatic groups are bonded directly to one Si atom. A hologram recording medium () has a hologram recording material layer ().

The present invention provides a hologram recording material which attains high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low shrinkage, and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising: an organometallic compound at least containing at least two kinds of metals, oxygen, and an aromatic group, and having an organometallic unit wherein two aromatic groups are bonded directly to one metal; metal oxide fine particles; and a photopolymerizable compound. For example, the metal oxide fine particles are selected from the group consisting of silica fine particles, alumina fine particles, titania fine particles, zirconia fine particles, and complex oxide fine particles containing one or more kinds of metal atoms which constitute said four metal oxides. A hologram recording mediumhas a hologram recording material layer

The present invention provides a hologram recording material which is not required to be subjected to pre-exposure treatment at the time of recording, attains high refractive index change, high sensitivity, low scattering, environment resistance, durability, low dimensional change, and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising a matrix material having a softening temperature of 50&#xb0; C. or higher, and a photopolymerizable monomer which is in a liquid phase state at room temperature. The matrix material is preferably contained in an amount of 50% by weight or more and 90% by weight or less of the whole of the hologram recording material. A softening temperature of the hologram recording material is preferably 0&#xb0; C. or higher.

Growing community of inventors

Tokyo, Japan

Jiro Yoshinari