Carnegie Mellon University

Read Rite Corporation

Nve Corporation

Jian-Gang Zhu

Robert Earl Rottmayer

Hua-Ching Tong

Francis H Liu

Lawrence Thomas Pileggi

Samuel Wonder Yuan

David Eugene Laughlin

Minshen Tan

David M Bromberg

Xiaochun Zhu

Tai Min

Kyusik Sin

Ronald A Barr

Chih-Huang Lai

Gary A Prinz

Xin Liang Li

William Messner

Hai Li

Yi Luo

John M Anderson

Chia-Ling Chien

Vincent Sokalski

Xiangdong Lin

Qinli Ma

Matthew Moneck

Youfeng Zheng

En Yang

A memory device includes a plurality of layers forming a stack. The plurality of layers include a spin polarization layer having a magnetic anisotropy approximately perpendicular to a plane of the spin polarization layer, an antiferromagnetic layer having an antiferromagnetic material, a ferromagnetic layer that is exchange coupled to the antiferromagnetic layer, where the antiferromagnetic layer is between the ferromagnetic layer and the spin polarization layer, and a storage layer having a magnetization direction that indicates a memory state of the storage layer. The memory state is switched by an amount of current through the stack. The spin polarization layer, the ferromagnetic layer, and the antiferromagnetic layer are configured to reduce the amount of current through the stack for switching the magnetization direction of the storage layer relative to an amount of current through a memory device without the spin polarization layer, the ferromagnetic layer, and the antiferromagnetic layer.

Resonance rotating spin-transfer torque memory device

A memory array that comprises three dimensionally stacked two-dimensional memory arrays. The memory array includes a first layer and a second layer oriented orthogonal to the first layer. The memory array further includes a magnetic tunnel junction adjacent to each of the first layer and the second layer. The magnetic tunnel junction further includes a first magnetic layer adjacent to the second layer. Additionally, the magnetic tunnel junction includes a second magnetic layer adjacent to the first layer. The magnetic tunnel junction also includes a tunnel layer adjacent to the first magnetic layer and the second magnetic layer.

3D perpendicular magnetic crossbar memory

An oscillation mechanism comprises a first spin-polarization layer having a first magnetic moment; a second spin-polarization layer having a second magnetic moment, wherein an orientation of the second magnetic moment is configured to oppose an orientation of the first magnetic moment; and a field-generating layer disposed between the first spin-polarization layer and the second spin-polarization layer for generating a magnetic field that oscillates around one or more of the first and second magnetic moment orientations.

Dual-side spin transfer spin torque oscillator

A recording head includes a near-field transducer configured to heat one or more portions of a magnetic storage layer to generate a thermal profile in the magnetic storage layer. The recording head includes a write pole configured to generate a magnetization pattern, in the magnetic storage layer, that overlaps with the thermal profile in the magnetic storage layer. The write pole includes a non-uniform surface that faces the magnetic storage layer, the non-uniform surface configured to cause a portion of the magnetization pattern to be approximately linear.

Heat-assisted magnetic recording head having a non-uniform air-bearing surface

This disclosure relates to a memory device that includes at least one magnetic track on a substrate, wherein the at least one magnetic track comprises one or more magnetic domains. Contacts can be disposed on the at least one magnetic track according to a predetermined arrangement to form a plurality of bitcells on the at least one magnetic track, wherein each one of the plurality of bitcells is configured to store at least one magnetic domain. The device can include a timing circuit connected to the contacts, with the timing circuit being configured to apply to the contacts multiple phases of electric currents according to a predetermined timing sequence to cause the at least one magnetic domain to shift from the each one of the plurality of bitcells to an adjacent one of the plurality of bitcells on the at least one magnetic track.

Magnetic shift register

In one aspect, a nonvolatile magnetic logic device comprises an electrically insulating layer, a write path, and a read path. The write path comprises a plurality of write path terminals and a magnetic layer having a uniform magnetization direction that is indicative of a direction of magnetization of the magnetic layer in a steady state. A logic state is written to the nonvolatile magnetic logic device by passing a current through the plurality of write path terminals. The read path comprises a plurality of read path terminals for evaluation of the logic state. The electrically insulating layer promotes electrical isolation between the read path and the write path and magnetic coupling of the read path to the write path.

Nonvolatile magnetic logic device

A process of fabricating a perpendicular magnetic recording medium. In one embodiment, the process may comprise forming a metallic buffer layer with a (002) texture on an underlayer using a deposition process performed at a temperature below 30&#xb0; C. The underlayer may have a crystalline (001) texture. The process may further comprise forming a perpendicular magnetic recording layer on top of the metallic buffer layer using a deposition process performed at a temperature above 350&#xb0; C. The magnetic recording layer may comprise a magnetic material with a L1crystalline structure and with a c-axis perpendicular to a plane of the perpendicular magnetic recording layer. The process may further comprise removing metal of the metallic buffer layer from a top surface of the perpendicular magnetic recording layer that moved to the top surface of the perpendicular magnetic recording layer during the forming of the perpendicular magnetic recording layer.

Buffer layers for L10 thin film perpendicular media

A magnetic microstructure comprising (i) a magnetic storage layer having a magnetic easy axis perpendicular to a film plane of the storage magnetic layer; (ii) a magnetic assist layer having a magnetic easy axis in the film plane; and (iii) a phase transition interlayer between the magnetic storage layer and the magnetic assist layer. The phase transition layer comprises a material, such as FeRh, that switches from antiferromagnetic at ambient to ferromagnetic at a transition temperature that is greater than ambient, but below the Curie temperature. When the phase transition interlayer is in antiferromagnetic phase, there exists little magnetic coupling between the storage and assist layers. When the interlayer changes to ferromagnetic phase, the interlayer couples the magnetic moments of the storage and assist layer ferromagnetically. If the anisotropy field-thickness product of the two layers is similar and the coupling is sufficiently strong, the effective magnetic anisotropy of the storage layer and the assist layer essentially vanishes. That way, the required write field at the recording temperature needs only to be a few percent of the ambient anisotropy field of the storage layer.

Binary anisotropy media

A magnetic memory or MRAM memory system comprising an M&#xd7;N crossbar array of MRAM cells. Each memory cell stores binary data bits with switchable magnetoresistive tunnel junctions (MJT) where the electrical conductance changes as the magnetic moment of one electrode (the storage layer) in the MJT switches direction. The switching of the magnetic moment is assisted by a phase transition interlayer that transitions from antiferromagnetic to ferromagnetic at a well defined, above ambient temperature.

Crossbar diode-switched magnetoresistive random access memory system

A perpendicular spin-torque-driven magnetic oscillator is disclosed. According to various embodiments, the magnetic oscillator comprises a magnetic reference stack, a magnetic oscillating stack, and an interlayer between the reference stack and the oscillating stack such that the reference stack and the oscillating stack are exchange coupled. The reference stack may have sufficient perpendicular anisotropy such that it causes, via the spin momentum transfer effect, the spin polarization of the conducting electrons in the oscillating stack to produce a spin torque on the local magnetization of the oscillating layer. As such, the oscillating stack may produce a sustained gyromagnetic oscillation around the perpendicular axis of the oscillating stack when (i) the oscillating stack and the reference stack have opposite magnetizations and (ii) there is a direct current flowing in the magnetic oscillator from the oscillating stack to the reference stack. Also, the oscillating stack may produce a sustained gyromagnetic oscillation when (i) the oscillating stack and the reference stack are magnetized in the same direction and (ii) there is a direct current flowing in the magnetic oscillator from the reference stack to the oscillating stack.

Perpendicular spin-torque-driven magnetic oscillator

A ferromagnetic thin-film based array of directed magnetic field generating structures having a plurality of toroidally shaped layer stacks each with a pair of ferromagnetic material layers separated by an intermediate layer of nonmagnetic material. Electrical connections are made to opposite sides thereof. A serpentine first side electrical conductor is folded back so as to have parallel branches and together zigzag to cross over each stack on one side thereof. A serpentine second side electrical conductor, also folded back so as to have parallel branches, can be further provided with these branches together zigzagging to cross each stack on an opposite side thereof. These first and second side electrical conductors can be electrically joined to form an array electrical conductor.

Radial field generating selection conductor device

Various embodiments of a magnetic memory element, including a storage layer and a reference layer, are disclosed. The storage layer includes two conjugate magnetic domain segments having opposing helicities. The reference layer is permanently magnetized. A non-magnetic layer is interposed between the two magnetic layers. The boundaries of the two conjugate magnetic domain segments of the storage layer define domain walls along the radial direction thereof. The magnetic moment direction of one domain wall points inward and the magnetic moment direction of the other domain wall points outward. The two domain walls always attract each other, leaving one segment significantly larger than the other. These two different conditions (each longer the other) define two binary data states. By sending a vertical current through the magnetic memory element, transitions between the memory states can be achieved. Also disclosed are a memory cell, a memory device, and a computing device.

Magnetic memory element and memory device including same

A magnetic sensor. According to one embodiment, the sensor comprises a synthetic antiferromagnetic (SAF) layer having first and second wing regions and an active region therebetween. The SAF layer includes a non-magnetic metal layer having first and second wing region portions and an active region portion therebetween, the non-magnetic metal layer including first and second opposing surfaces. The SAF layer also includes a first ferromagnetic layer adjacent a first surface of the non-magnetic metal layer and having first and second wing region portions and an active region portion therebetween. The SAF layer further includes a second ferromagnetic layer adjacent the second surface of the non-magnetic metal layer and including a first wing region portion adjacent the first wing region portion of the non-magnetic metal layer and a second wing region portion adjacent the second wing region portion of the non-magnetic metal layer. The second ferromagnetic layer is of adequate thickness such that the magnetic susceptibility of the first and second wing region portions of the first ferromagnetic layer is substantially zero when magnetic fields are present only in the first and second wing regions.

Magnetic sensor with reduced wing region magnetic sensitivity

The invention relates to control systems for data storage media. More particularly, the invention relates to a system, method and apparatus for forming various frequency modulation patterns on storage media for providing position error signals. The invention also relates to forming various frequency modulation patterns on storage media for providing position error signals having a continuously varying frequency that is proportional to the position of a read/write transducer head within a track defined on a storage medium. The invention also relates to providing a demodulated signal that is proportional to a continuously varying position error signal frequency and thus to the position of the read/write head within a track defined on a storage medium.

Frequency modulation pattern for disk drive assemblies

A magnetoresistive read head. The magnetoresistive read head includes a magnetoresistive element including a lower surface and an upper surface, wherein an electrical resistance of the magnetoresistive element varies in response to varying magnetic fields adjacent to the lower surface of the magnetoresistive element, and a magnetic element adjacent to the upper surface of the magnetoresistive element.

Growing community of inventors

Pittsburgh, PA, United States of America

Jian-Gang Zhu