Seagate Technology Incorporated

Western Digital (fremont), Inc.

Western Digital Technologies, Inc.

Hgst Netherlands, B.v.

Seagate Technologies, Inc.

Haiwen Xi

Dimitar Velikov Dimitrov

Song Sheng Xue

Yuankai Zheng

Xiaobin Wang

Yiran Chen

Kaizhong Gao

Wenzhong Zhu

Dexin Wang

Xiaohua Lou

Michael Xuefei Tang

Olle Gunnar Heinonen

Hongyue Liu

Insik Jin

Zheng Gao

Hai Li

Yong Lu

Antoine Khoueir

Alan Xuguang Wang

Brian Lee

Wei Tian

Harry Hongyue Liu

Paul E Anderson

Yang Li

Wonjoon Jung

Andreas Karl Roelofs

Shaoping Li

Pat J Ryan

Patrick Joseph Ryan

Henry F Huang

Shuiyuan Huang

Eileen Yan

Yiming Shi

Neil Leslie Robertson

Ming Mao

Jordan Asher Katine

Ming Sun

Sining Mao

Patrick Braganca

Qingbo Wang

Xuebing Feng

Gerardo Bertero

Rongfu Xiao

Qunwen Leng

Steven C Rudy

Venugopalan Vaithyanathan

Shihai He

Hardayal Singh Gill

Daniele Mauri

Lei Wang

Feng Q Liu

Nurul Amin

Kirill A Rivkin

Ge Yi

Dadi Setiadi

Satoru Araki

Dian Song

Christopher L Beaudry

Robert William Lamberton

Yizhang Yang

Dustin William Erickson

Zhihong Zhang

Zhipeng Li

Jun Zheng

Haifeng Wang

Yuan Yan

Rod V Bowman

Markus Siegert

Jianxin Fang

Yingbo Zhang

Xin Cao

Wei Tan

Hiroaki Chihaya

Chang Man Park

Jun Ouyang

Srikanth Ganesan

Ruisheng Liu

A system according to one embodiment includes a pinned layer; a spacer layer above the pinned layer; a free layer above the spacer layer; a heating device, for heating the free layer to induce a paramagnetic thermal instability in the free layer whereby a magnetization of the free layer randomly switches between different detectable magnetic states upon heating thereof; and a magnetoresistance detection circuit for detecting an instantaneous magnetic state of the free layer.

Random number generator by superparamagnetism

Apparatuses and methods for providing thin shields in a multiple sensor array are provided. One such apparatus is a magnetic read transducer including a first read sensor, a second read sensor, and a shield assembly positioned between the first read sensor and the second read sensor at an air bearing surface (ABS) of the magnetic read transducer, the shield assembly including a first shield layer assembly having a first footprint with a first area, and a second shield layer assembly having a second footprint with a second area, where the second area is greater than the first area.

Apparatuses and methods for providing thin shields in a multiple sensor array

A magnetic read apparatus has a media-facing surface (MFS) and includes a read sensor, a magnetic bias structure and an insulating layer. The read sensor has a side, a front occupying part of the MFS and a back. The read sensor includes a free layer, a pinned layer and a barrier layer between the free and pinned layers. The barrier layer has a barrier layer coefficient of thermal expansion. The magnetic bias structure is adjacent to the side of the free layer. The insulating layer includes first and second portions. The first portion of the insulating layer is between the read sensor side and the magnetic bias structure. The second portion of the insulating layer adjoins the read sensor back. The insulating layer has an insulating layer coefficient of thermal expansion that is at least &#x2153; of and not more than 5/3 of the barrier layer coefficient of thermal expansion.

Read sensor having an insulating layer capable of use in two-dimensional magnetic recording

In one general embodiment, a system includes at least one magnetic nanoparticle; a heating device for heating the at least one magnetic nanoparticle to induce a paramagnetic thermal instability in the at least one magnetic nanoparticle whereby a magnetization of the magnetic nanoparticle randomly switches between different detectable magnetic states upon heating thereof; and a magnetoresistance reading device for detecting an instantaneous magnetic state of the magnetic nanoparticle.

A magnetic shield for a magnetic recording head includes a plurality of ferromagnetic layers, a spacer layer, and a buffer layer, wherein the buffer layer includes Co, Fe, B, or a combination thereof and effectively reduces irregular grain growth within the ferromagnetic layers, the spacer layer includes Ru, and the ferromagnetic layers magnetically couple through each of the buffer layer and the spacer layer.

Magnetic shield for magnetic recording head

Magnetic spin-torque memory cells, often referred to as magnetic tunnel junction cells, which have magnetic anisotropies (i.e., magnetization orientation at zero field and zero current) of the associated ferromagnetic layers aligned perpendicular to the wafer plane, or 'out-of-plane'. A memory cell may have a ferromagnetic free layer, a first pinned reference layer and a second pinned reference layer, each having a magnetic anisotropy perpendicular to the substrate. The free layer has a magnetization orientation perpendicular to the substrate that is switchable by spin torque from a first orientation to an opposite second orientation.

ST-RAM cells with perpendicular anisotropy

Devices and methods for generating a random number that utilizes a magnetic tunnel junction are disclosed. An AC current source can be in electrical connection to a magnetic tunnel junction to provide an AC current to the magnetic tunnel junction. A read circuit can be used to determine a bit based on a state of the magnetic tunnel junction. A rate of production of the bits can be adjusted, such as by adjusting a frequency or amplitude of the AC current. A probability of obtaining a '0' or '1' bit can be managed, such as by an addition of DC biasing to the AC current.

Random bit generator that applies alternating current (AC) to magnetic tunnel junction to generate a random bit

A method and apparatus for stray magnetic field compensation in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a first tunneling barrier is coupled to a reference structure that has a perpendicular anisotropy and a first magnetization direction. A recording structure that has a perpendicular anisotropy is coupled to the first tunneling barrier and a nonmagnetic spacer layer. A compensation layer that has a perpendicular anisotropy and a second magnetization direction in substantial opposition to the first magnetization direction is coupled to the nonmagnetic spacer layer. Further, the memory cell is programmable to a selected resistance state with application of a current to the recording structure.

Non-volatile memory with stray magnetic field compensation

A magnetic read sensor having improved robustness to withstand thermal variations resulting from thermal fly height heating. Improved thermal robustness comes as a result of improved pinned layer pinning. The read head includes an AFM layer having an increased thickness to provide a higher blocking temperature. The read head further includes a pinned layer structure that includes a first magnetic layer adjacent to and exchange coupled with the AFM layer. The first layer comprises a Co&#x2014;Fe layer with an increased Fe content of 20-30 atomic percent. The pinned layer structure also includes a second magnetic layer that is antiparallel coupled with the AP1 layer. The AP2 layer can be a multi-layer structure that includes a layer of CoFe, a layer of Co&#x2014;Fe&#x2014;Hf formed on the layer of Co&#x2014;Fe, a layer of Co&#x2014;Fe&#x2014;B formed on the layer of Co&#x2014;Fe&#x2014;Hf, and a second layer of Co&#x2014;Fe formed on the layer of Co&#x2014;Fe&#x2014;B.

Magnetic sensor having improved resistance to thermal stress induced instability

An apparatus and associated method for a non-volatile memory cell with a phonon-blocking insulating layer. In accordance with various embodiments, a magnetic stack has a tunnel junction, ferromagnetic free layer, pinned layer, and an insulating layer that is constructed of an electrically and thermally insulative material that blocks phonons while allowing electrical transmission through at least one conductive feature.

Memory cell with phonon-blocking insulating layer

Method and apparatus for writing data to a magnetic memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In accordance with various embodiments, a write current is applied through a selected magnetic memory cell to initiate magnetic precession of the selected cell to a desired magnetic state. A field assist current is concurrently flowed through an adjacent memory cell to generate a magnetic field that assists in the precession of the selected cell to the desired magnetic state.

Using a nearby cell to provide field assisted switching in a magnetic memory array

A method of producing bit-patterned media is provided whereby a shell structure is added on a bit-patterned media dot. The shell may be an antiferromagnetic material that will help stabilize the magnetization configuration at the remanent state due to exchange coupling between the dot and its shell. Therefore, this approach also improves the thermal stability of the media dot and helps each individual media dot maintain a single domain state.

Method of manufacturing magnetic dots

A method of switching the magnetization orientation of a ferromagnetic free layer of an out-of-plane magnetic tunnel junction cell, the method including: passing an AC switching current through the out-of-plane magnetic tunnel junction cell, wherein the AC switching current switches the magnetization orientation of the ferromagnetic free layer.

Method of switching out-of-plane magnetic tunnel junction cells

An apparatus and method for storing data in a semiconductor memory. In accordance with some embodiments, the semiconductor memory has a continuous storage layer of soft ferromagnetic material having opposing top and bottom surfaces with overall length and width dimensions and an overall thickness dimension between the opposing top and bottom surfaces. A plurality of spaced apart, discrete reference layers are adjacent a selected one of the opposing top or bottom surfaces of the continuous storage layer with each having a fixed magnetic orientation. A plurality of spaced apart, discrete barrier layers are disposed in contacting relation between the discrete reference layers and the continuous storage layer.

Magnetic memory element with multi-domain storage layer

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Prior Lake, MN, United States of America

Haiwen Xi