Magnon Spin Valve Memory With Topological Readout for Low-Power Switching

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Solution Overview

Problem

Current magnetic memory devices face challenges in achieving high integration and low power consumption while maintaining reliability, particularly in efficiently switching and reading data due to limitations in magnetization direction control and resistance state detection.

Innovation Solution

A magnon spin valve-based magnetic memory device is developed, incorporating a spin detection layer with topological materials or weyl semimetals, a free layer and reference layer made of ferromagnetic insulators, and an exchange coupling layer, which utilizes spin orbit torque and magnon-mediated spin torque for magnetization switching and resistance state detection, reducing Joule heating and enhancing signal amplification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional magnetic memory devices use traditional magnetic materials and magnetization control methods, then data storage functionality is achieved, but critical current density for magnetization switching is high and power consumption increases

Engineering Contradiction:

Improvepower consumptionVSAvoidmagnetization switching reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the material parameters by using topological insulator materials (such as (BixSb1-x)2Te3) with high spin Hall angles instead of conventional magnetic materials. This parameter change enables efficient spin-orbit coupling, allowing magnetization switching at lower critical current densities while maintaining switching reliability through the unique topological properties of the materials.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures including topological insulator layers combined with ferromagnetic metal layers, and introduces exchange coupling layers with antiferromagnetic materials. These composite structures leverage the complementary properties of different materials to achieve low-power magnetization switching while ensuring stable magnetic states and reliable data storage functionality.

Inventive Principle:

Principle #40Composite materials

2Productivity

If magnetic memory devices are designed for high integration, then device density increases, but signal detection precision and read signal amplification become difficult

Engineering Contradiction:

Improvedevice integration densityVSAvoidread signal detection precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces spin detection layers made of topological insulator materials as intermediary elements between the magnetic storage layers and the readout circuitry. These intermediary layers enhance spin-orbit coupling effects, providing signal amplification during read operations and improving detection precision even in highly integrated device configurations where signal strength is typically weakened.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If conventional current methods are used for magnetization switching, then data writing is achieved, but Joule heating increases and device reliability decreases

Engineering Contradiction:

Improvedevice stabilityVSAvoidJoule heating

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces conventional charge-current-based magnetization switching with a spin-current-based mechanism utilizing the spin Hall effect in topological insulator materials. This substitution eliminates direct Joule heating in the magnetic layers by using spin-orbit coupling to transfer angular momentum, thereby reducing energy loss as heat and improving device stability and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 improves data writing and reading reliability by reducing critical current density for magnetization switching, maintaining stable off-states, and amplifying read signals, thus addressing the demands for high integration and low power consumption in magnetic memory devices.

Implementation Method 1

utilizes spin orbit torque and magnon-mediated spin torque for magnetization switching

Methodology Applied

Scientific EffectSpin orbit torque:

Implementation Method 2

utilizes spin orbit torque and magnon-mediated spin torque for magnetization switching and resistance state detection

Methodology Applied

Scientific EffectMagnon-mediated spin torque:

Implementation Method 3

each of the reference layer and the free layer includes a ferromagnetic insulator

Methodology Applied

Scientific EffectFerromagnetism: Ferromagnetism

Data Source

PatentUS20250017116A1Magnetic memory device using magnon spin valve including topological material and exchange coupling

Publication Date: 2025.01.09 KOREA ADVANCED INST OF SCI & TECH

AI summary

According to an embodiment of the inventive concept, a magnetic memory device includes a substrate on which a transistor controlled by a word line is disposed, a spin detection layer disposed on the substrate, and a magnon spin valve disposed on the spin detection layer. Here, the magnon spin valve includes a free layer disposed on the spin detection layer, a reference layer disposed on the free layer, and a spacer disposed between the free layer and the reference layer. Also, one edge of the spin detection layer is connected to a source/drain region of the transistor, the other edge of the spin detection layer is connected to a source line, and the magnon spin valve is disposed on a portion between the one edge and the other edge of the spin detection layer. The spin detection layer includes a topological material or a weyl semimetal. Each of the reference layer and the free layer includes a ferromagnetic insulator.