Magnetic Memory Domain Wall Shifting via Localized SOT Metal Layer
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Solution Overview
Problem
Magnetic memories face issues with high shift currents required to move domain walls, leading to potential congestion and inefficiencies in domain wall shifting due to the absence of a nonmagnetic metal layer capable of generating spin-orbit-torque (SOT) in the connection region between magnetic parts.
Innovation Solution
Incorporating a nonmagnetic metal layer capable of generating SOT along a curved third magnetic part connecting the first and second magnetic parts, which assists in shifting domain walls without covering the entire length of the first magnetic part, thereby preventing an increase in shift current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a nonmagnetic metal layer capable of generating spin-orbit-torque is added to assist domain wall shifting, then domain wall movement becomes smoother and more efficient, but the device structure becomes more complex
Solution Approach 1:
The nonmagnetic metal layer is strategically positioned only in the connection region between magnetic parts where domain wall shifting occurs, rather than uniformly across the entire structure. This localized placement provides the necessary spin-orbit-torque assistance exactly where needed while minimizing additional structural complexity and material usage.
2Productivity
If the nonmagnetic metal layer covers the entire length of the first magnetic part, then domain wall shifting is maximally assisted, but the shift current increases significantly
Solution Approach 1:
The nonmagnetic metal layer is confined to the connection region between magnetic parts rather than extending along the entire length of the first magnetic part. This localized configuration provides sufficient spin-orbit-torque assistance for smooth domain wall movement while avoiding the excessive shift current that would result from full-length coverage.
Solution Approach 2:
Instead of applying the nonmagnetic metal layer excessively across the entire magnetic part structure, the invention uses partial coverage limited to the critical connection region. This partial action achieves the necessary domain wall shifting assistance without the harmful excessive effect of increased shift current.
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 configuration allows for smooth domain wall movement without congestion, reducing the shift current required and maintaining efficient domain wall shifting, thus addressing the inefficiencies in existing magnetic memory designs.
Implementation Method 1
a first nonmagnetic metal layer arranged along the third magnetic part, the first nonmagnetic metal layer including a first end portion on a side of the second portion
Data Source
AI summary
A magnetic memory according to an embodiment includes: a magnetic member including a first to third magnetic parts, the first magnetic part including a first portion and a second portion and extending in a first direction from the first portion to the second portion, the second magnetic part extending in a second direction that crosses the first direction, and the third magnetic part connecting the second magnetic part and the first portion; a first nonmagnetic metal layer arranged along the third magnetic part, the first nonmagnetic metal layer including a first end portion on a side of the second portion, a position of the first end portion along the first direction being between positions of the first and second portions along the first direction; and a first and second electrodes supplying a current between the first and second magnetic parts via the third magnetic part.