Spin-Orbit Torque Array With Two-State Magnetization Readout

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional hardware security devices using spin-orbit torque (SOT) are vulnerable to information loss due to changes in intermediate magnetic states under weak magnetic fields, and require power-consuming analog-to-digital converters (ADCs) for digital conversion.

Innovation Solution

A spin-orbit torque device array with a triple-layer structure of non-magnetic, magnetic, and oxide layers, utilizing anomalous Hall effect to saturate magnetization states to two stable positions, eliminating the need for ADCs and enhancing resistance to external magnetic fields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If pulse current with same intensity is applied to all devices, then intermediate magnetic state is achieved for random factor generation, but information loss occurs under weak magnetic fields

Engineering Contradiction:

Improveinformation lossVSAvoidmagnetic state stability

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent applies saturation currents with different magnitudes to different devices based on their individual switching characteristics. By adjusting the current magnitude parameter for each device, the magnetization state is saturated to a stable state, preventing information loss under weak magnetic fields while maintaining the random factor generation capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary saturation of magnetization states before using the devices for security applications. By pre-applying saturation currents to establish stable magnetization states, the devices become resistant to subsequent weak magnetic field interference, ensuring information integrity during operation.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If analog-to-digital converter is used for digital conversion, then digital bitmap is acquired, but power consumption increases

Engineering Contradiction:

Improvepower consumptionVSAvoiddigital conversion capability

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent extracts and eliminates the ADC component from the system by directly generating digital output signals from the magnetization states. The spin-orbit torque devices produce distinguishable electrical signals corresponding to different magnetization states, which can be directly interpreted as digital values without requiring separate analog-to-digital conversion circuitry.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/electronic ADC conversion process with a direct magnetic-to-electrical signal transduction mechanism. The spin-orbit torque effect enables direct conversion of magnetization states into distinguishable electrical signals, substituting the need for complex ADC hardware with a more efficient physical transduction process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If intermediate magnetic state is used for random factor generation, then security device pattern is acquired, but resistance to external magnetic fields decreases

Engineering Contradiction:

Improveresistance to external magnetic fieldsVSAvoidmagnetization state stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies saturation currents in advance to cushion against the effects of weak external magnetic fields. By pre-establishing saturated magnetization states, the devices gain resistance to subsequent magnetic field interference, protecting the stored information from being altered by external fields during operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 device array provides secure, low-power operation with robust magnetic states, improving resistance to external fields and eliminating the need for ADCs, thus enhancing security and reducing power consumption.

Implementation Method 1

utilizing anomalous Hall effect to saturate magnetization states to two stable positions

Methodology Applied

Scientific EffectAnomalous Hall effect: Hall Effect

Implementation Method 2

spin-orbit torque (SOT), which is a method of electrically controlling the vertical magnetization of a thin film of a magnetic substance

Methodology Applied

Scientific EffectSpin-orbit torque:

Data Source

PatentUS12514135B2Spin-orbit torque device array and method of manufacturing spin-orbit torque device array

Publication Date: 2025.12.30 HYUNDAI MOTOR CO LTD

AI summary

An embodiment spin-orbit torque device array includes a plurality of single devices, each device including a non-magnetic layer, a magnetic layer bonded to the non-magnetic layer, and an upper layer bonded to the magnetic layer, wherein the upper layer includes oxide, and wherein a magnetization state of each of the single devices has only two states, the two states being an up state and a down state.