Spin Hall Effect Layer in Magnetic Write Gap
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Solution Overview
Problem
Existing magnetic recording technologies face challenges such as reduced writability as write head sizes shrink, reliability concerns, limited write gap thickness, and synchronization difficulties in Spin Hall Effect assisted magnetic recording (SHAMR) schemes, particularly due to current density thresholds and heating issues.
Innovation Solution
A SHAMR scheme is developed with a Spin Hall Effect (SHE) layer in the write gap between the main pole and trailing shield, utilizing giant positive or negative Spin Hall Angle materials, where direct currents are applied to induce transverse spin transfer torque without a current density threshold, reducing fabrication steps and avoiding SHE layer protrusion, and allowing for reduced write gap thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Spin Hall Effect layer is used in conventional SHAMR designs with current applied across the layer synchronized with write current, then magnetic recording assist is achieved, but synchronization difficulties and heating issues occur
Solution Approach 1:
The patent extracts the Spin Hall Effect layer from the conventional configuration where current flows across the layer synchronized with write current. Instead, the SHE layer is positioned in the write gap with current applied directly to it independently from the write current, eliminating the synchronization requirement and reducing heating issues.
Solution Approach 2:
The SHE layer acts as an intermediary element positioned in the write gap between the main pole and trailing shield. By applying current directly to this intermediary SHE layer, the system generates spin transfer torque to assist magnetic recording without requiring synchronization with the write current, thereby simplifying the overall system control.
2Quantity of substance
If write head size is reduced to increase data areal density, then storage capacity increases, but writability degrades
Solution Approach 1:
The patent changes the physical parameters of the magnetic recording system by introducing a Spin Hall Effect layer with giant positive or negative Spin Hall Angle. This allows generation of enhanced magnetic fields through spin transfer torque, improving writability even as the write head size is reduced to increase data areal density.
3Power
If current density threshold is required for SHE layer operation, then spin transfer torque is generated, but heating issues and reliability concerns arise
Solution Approach 1:
The patent applies local quality by positioning the SHE layer specifically in the write gap region where it interacts locally with the main pole and trailing shield. The current is applied directly to this localized SHE layer, generating spin transfer torque precisely where needed while minimizing overall heating in the write head structure.
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
This approach enhances overwrite, bit error rate, and transition sharpness while improving device reliability and transition speed, eliminating the need for synchronization with write current and reducing heating issues.
Implementation Method 1
SHE causes electrons with opposite spins to be scattered to opposite directions perpendicular to the charge current density as a result of strong spin-orbit coupling in the conducting layer
Implementation Method 2
the electrons transfer a portion of their angular momentum to FM2. As a result, spin-polarized current can switch the magnetization direction of FM2 if the current density is sufficiently high
Data Source
AI summary
A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a SHE layer comprising a giant Spin Hall Angle material is formed in a write gap between a main pole (MP) trailing side and trailing shield (TS). The SHE layer contacts either the MP or TS, and has a front side at the air bearing surface or recessed therefrom. In one embodiment, a current (I1) is applied between the MP trailing side and SHE layer and is spin polarized to generate a first spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field. In a second embodiment, a current (I2) is applied between the SHE layer and TS and is spin polarized to generate a second spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.