Non-Localized Spin Valve Reader with SOT Layer and Spin Concentration
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Solution Overview
Problem
Existing magnetic recording heads, particularly those using non-localized spin valve designs, suffer from limited spin injection efficiency due to a spin polarization of less than 1, resulting in poor signal output and inaccurate data reading.
Innovation Solution
Incorporating a spin orbit torque (SOT) layer, such as BiSb, in the spin generator recessed from the media facing surface, and configuring the non-magnetic layer to have a triangular or trapezoidal shape to concentrate spin current, enhancing spin current injection to the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pinned layer and ferromagnetic layer are used for spin injection in NLSV design, then the read head structure is established, but the spin injection efficiency is limited due to spin polarization less than 1, resulting in poor signal output
Solution Approach 1:
The patent changes the material parameter of the spin generator from conventional pinned layer/ferromagnetic layer to spin orbit torque (SOT) layer materials such as BiSb (bismuth antimony). This material substitution fundamentally alters the spin injection mechanism, enabling spin polarization greater than 1 and significantly improving spin current injection efficiency and signal output quality
Solution Approach 2:
The patent employs composite material structures including SOT layers (BiSb), non-magnetic layers (Ru, Rh, Ir), and magnetic layers with specific configurations. These composite structures work synergistically to enhance spin current generation and transport, resolving the limitation of conventional single-material spin injection approaches
2Reliability
If the non-magnetic layer is configured with triangular or trapezoidal shape, then spin current concentration is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent introduces asymmetric geometric configurations for the non-magnetic layer, specifically triangular and trapezoidal shapes, instead of conventional symmetric rectangular structures. This asymmetry is strategically designed to concentrate spin current flow toward the sensor region, enhancing signal strength while the fabrication methods described maintain compatibility with standard semiconductor manufacturing processes
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The enhanced spin current injection leads to improved signal output and accurate data reading capabilities in magnetic recording devices.
Implementation Method 1
the spin generator comprises at least one spin orbit torque (SOT) layer
Implementation Method 2
The sensor is configured to detect a read signal using a first voltage lead and a second voltage lead
Data Source
AI summary
The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a sensor disposed at a media facing surface (MFS) and a spin generator spaced from the sensor and recessed from the MFS. The sensor and spin generators are disposed on a non-magnetic layer. The sensor comprises a free layer and the spin generator comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise topological material such as BiSb. The sensor is configured to detect a read signal using a first voltage lead and a second voltage lead. The spin generator is configured to inject spin current through the non-magnetic layer to the sensor using a first current lead and a second current lead. The shape of the non-magnetic layer is a triangular or trapezoidal shape to further concentrate spin current.