Tdk Corporation

Kuniyasu Ito

Katsuyuki Nakada

Tatsuo Shibata

Takahiro Suwa

Masato Takahashi

Kazuhiro Hattori

Makoto Moriya

Kazuya Shimakawa

Hideaki Fukuzawa

Tsuyoshi Komaki

Yuji Kakinuma

Tetsuya Shibata

Takumi Aoki

A magnetic domain wall movement type magnetic recording element according to an embodiment includes: a first ferromagnetic layer which includes a ferromagnetic body; a non-magnetic layer which faces the first ferromagnetic layer; and a magnetic recording layer which faces a surface of the non-magnetic layer on a side opposite to the first ferromagnetic layer and extends in a first direction. A first surface of the magnetic recording layer which faces the non-magnetic layer has a smaller arithmetic mean roughness than a second surface opposite to the first surface.

Domain wall motion type magnetic recording element

A integrated light source module includes a planar optical waveguides layer having N light incident ports aligned with respect to each other, M light exit ports aligned with respect to each other, and optical waveguides connected to the N light incident ports and the M light exit ports, and N optical semiconductor devices facing each of the N light incident ports arranged so that light emitted from each of the N optical semiconductor devices can be incident on each of the N light incident ports, wherein light emitted from the M light exit ports can be applied to an object to be irradiated.

Integrated light source module

A multiply-accumulate calculation device includes: multiple calculation units which generates output signals by multiplying an input signal corresponding to an input value and having a rising part, a signal part, and a falling part by a weight, and output the output signals; an accumulate calculation unit configured to calculate a sum of the output signals output from the plurality of multiple calculation units; and a correction unit configured to execute correction processing for correcting the sum of the output signals on the basis of a correction value including at least one of a first value incorporated into the sum by a current flowing into variable resistors of the multiple calculation units due to the rising part of the input signal, and a second value incorporated into the sum by a current flowing into the variable resistors of the multiple calculation units due to the falling part of the input signal.

Product-sum operation device, logical calculation device, neuromorphic device, and multiply-accumulate method

A magnetic domain wall movement type magnetic recording element includes: a first ferromagnetic layer which includes a ferromagnetic body; a non-magnetic layer which faces the first ferromagnetic layer; and a magnetic recording layer which faces a surface of the non-magnetic layer on a side opposite to the first ferromagnetic layer and extends in a first direction. The magnetic recording layer has a concave-convex structure on a second surface opposite to a first surface which faces the non-magnetic layer.

A magnetic element including a magnetoresistive effect film (MEF). Magnetic element includes an MEF and nonmagnetic spacer layer, first and second ferromagnetic layers, wherein layers being disposed with nonmagnetic spacer layer interposed therebetween, pair of electrodes disposed with MEF interposed therebetween in stacking direction of MEF at least two first soft magnetic layers, coil, and second soft magnetic layer magnetically connected to coil, wherein second soft magnetic layer has ring-like shape, spacing distance between second soft magnetic layer and MEF is larger than first soft magnetic layer and MEF, film thickness of second soft magnetic layer is larger than first soft magnetic layer, part of the two first soft magnetic layers overlaps a part of second soft magnetic layer in stacking direction of MEF, first and second soft magnetic layers are magnetically coupled to each other, and MEF is disposed between respective fore ends of two first soft magnetic layers.

Magnetic element

A magnetoresistive effect element includes a pair of first soft magnetic layers that are arranged opposite to each other so as to sandwich a magnetoresistive effect film; a second soft magnetic layer; and a coil that is windingly formed about the second soft magnetic layer. When a rear end region cross-sectional area of the first soft magnetic layers is defined as S1r and a tip end region cross-sectional area of the second soft magnetic layer is defined as S2f, S2f&#x3e;S1r is established, and when a tip end width of the first soft magnetic layers is defined as W1f and a rear end width of the first soft magnetic layers is defined as W1r, W1r&#x3e;W1f is established.

Thin film magnetic element having a pair of first soft magnetic layers sandwiching a magnetoresistive effect film and a coil windingly formed about a second soft magnetic layer

A thin-film magnetic oscillation element includes a pinned magnetic layer, a free magnetic layer, a nonmagnetic spacer layer provided between the pinned magnetic layer and the free magnetic layer, and a pair of electrodes, in which the easy axis of magnetization of the pinned magnetic layer lies in an in-plane direction of the plane of the pinned magnetic layer, and the easy axis of magnetization of the free magnetic layer lies in a direction normal to the plane of the free magnetic layer. Preferably, the relationship between the saturation magnetization Ms and the magnetic anisotropy field Ha of the free magnetic layer satisfies 1.257 Ms&#x3c;Ha&#x3c;12.57 Ms. More preferably, the free magnetic layer is composed of an alloy or a stacked film containing at least one element selected from Co, Ni, Fe, and B.

Thin-film magnetic oscillation element

Data track pattern regions, in which data track patterns are formed by concave/convex patterns, and servo pattern regions, in which servo patterns are formed by concave/convex patterns, are provided on a magnetic recording medium so as to be alternately disposed in a circumferential direction. At least one predetermined region that differs to the data track pattern regions is provided between two servo pattern regions that are adjacent in a circumferential direction. A concave/convex pattern including a plurality of first convex parts formed continuously in a radial direction is formed in each predetermined region.

Magnetic recording medium, stamper recording/reproducing apparatus and method of measuring a parameter

A magnetic recording medium having a recording layer formed in a concavo-convex pattern, which can allow a head to have stable flying characteristics. The recording layer is formed in a concavo-convex pattern, and concave portions of the concavo-convex pattern of the recording layer are filled with a non-magnetic material. The relationship of S&#x2266;3.6&#xd7;R holds, when R represents a concavo-convex ratio obtained by dividing an area of convex portions in a surface by an area of the concave portions in the surface, and S represents a difference in height between a concavity and a convexity of the surface. In the magnetic recording medium, an arithmetical mean deviation of the assessed profile of the surface is limited to 0.3 nm or more.

Magnetic recording medium

A recording/reproducing apparatus includes: a magnetic recording medium on which data track patterns are formed in data track pattern regions by a pattern with recording regions and non-recording regions and on which servo patterns are formed in servo pattern regions by the pattern; a recording head that writes signals on the medium; a reproducing head that reads signals written on the medium; and a control unit that controls the writing of signals by the recording head and the reading of signals by the reproducing head and measures a predetermined parameter for at least one of the recording head and the reproducing head by writing and reading measurement signals on the medium. The control unit writes the measurement signals using the recording head on first recording regions formed continuously in a radial direction of the medium out of the recording regions formed in the servo pattern regions, reads the measurement signals using the reproducing head, and measures the parameter based on the read measurement signals.

Recording/reproducing apparatus and method of measuring a parameter

A magnetic recording medium and a method of manufacturing the same which serve for stable head behavior and efficient recording of servo information. In each servo area, a magnetic layer is separated into a plurality of servo pattern unit parts for forming a predetermined servo pattern and a plurality of servo pattern gap filling parts patterned to fill gaps between the plurality of servo pattern unit parts partly. The servo pattern unit parts and the servo pattern gap filling parts are formed in different sizes so as to have different magnetic properties.

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Tokyo, Japan

Kuniyasu Ito