Western Digital Technologies, Inc.

Rohan Babu Nagabhirava

Quang Le

Cherngye Hwang

Xiaoyong Liu

Son T Le

Kuok San Ho

Brian Rodrick York

Hisashi Takano

Nam Hai Pham

Randy G Simmons

Huy H Ho

The present disclosure generally relates to temperature detection devices including a ferromagnetic (FM) material disposed at a media facing surface (MFS). The FM material is configured to produce a first electric voltage signal in response to a temperature gradient due to an anomalous Nernst effect. The temperature detection device may also include a spin-orbit torque (SOT) material abutting the FM material. The SOT material includes at least one of BiSb, a topological insulator, a topological half-Heusler alloy, or a weakly oxidized heavy metal. The SOT material is recessed from the MFS, wherein the SOT material is configured to receive a spin current parallel to the temperature gradient generated by a spin Seebeck effect in the FM material. The spin current is detectable as a second electric voltage signal via an inverse spin Hall effect. The first electric voltage signal is added to the second electric voltage signal.

Spin orbit torque based thermal sensor for insitu monitoring of magnetic recording head

The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprises a first shield, a BiSb layer disposed over the first shield (S), a free layer (FL) disposed over the BiSb layer, and a second shield (S) disposed over the FL. The S, the FL, and the Sare disposed at a media facing surface (MFS). The BiSb layer is recessed from the MFS a first distance of about 5 nm to about 20 nm. The FL has a length greater than the first distance. A notch and/or an insulation layer is disposed adjacent to the BiSb layer at the MFS. Current may be configured to flow vertically through the Sto the FL, and horizontally from the FL to the BiSb layer. Current may be configured to flow vertically through the Sto the S

SOT reader with recessed SOT topological insulator material

The present disclosure generally relates to a two dimensional magnetic recording (TDMR) spin-orbit torque (SOT) read head comprising bismuth antimony (BiSb) layers. The read head comprises a lower reader comprising a first SOT stack and an upper reader comprising a second SOT stack. The first SOT stack and the second SOT stack each individually comprise a BiSb layer recessed from a media facing surface (MFS) and a free layer exposed at the MFS. The BiSb layers of each SOT stack are recessed from the MFS a distance of about 5 nm to about 20 nm, the distance being less than a length of the free layers. In one embodiment, the lower reader and the upper reader share a current path. In another embodiment, the lower reader and the upper reader have separate current paths.

TDMR SOT read heads having recessed topological insulator materials

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Virginia Beach, VA, United States of America

Rohan Babu Nagabhirava