MEMTJ Logic Using MTJ Readout for Cascading Nonvolatile Switching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

MESO devices face limitations as logic gates due to weak spin-to-charge conversion mechanisms in their output modules, resulting in insufficient output current to switch the logic state of another device, and their potential use is hindered by the need for output voltages exceeding the coercive voltage of succeeding devices.

Innovation Solution

A magnetoelectric magnetic tunnel junction (MEMTJ) device is introduced, comprising a magnetoelectric switching capacitor coupled to a pair of magnetic tunnel junctions (MTJs) for reading out logic states, which provides low switching energy and a strong enough output signal to switch the logic state of another MEMTJ device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If MESO devices use spin-to-charge conversion mechanism, then logic state switching is achieved, but output current is insufficient to switch another MESO device

Engineering Contradiction:

Improveoutput currentVSAvoidcascading logic capability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent combines a magnetoelectric switching capacitor with a pair of magnetic tunnel junctions (MTJs) to form a hybrid MEMTJ device. The MTJs provide strong readout signals that can reliably switch subsequent devices, while the magnetoelectric capacitor provides low-power switching. This merging of two different device mechanisms resolves the contradiction between insufficient output current and unreliable cascading logic capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The device uses composite structure combining magnetoelectric materials (for low-power switching) and magnetic tunnel junction materials (for strong signal readout). This composite approach allows the device to simultaneously achieve low switching energy and sufficient output current for reliable cascading operations.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If magnetoelectric capacitor switches magnetization orientation, then logic state changes, but switching energy requirement is high

Engineering Contradiction:

Improvelogic state switchingVSAvoidswitching energy

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent changes the switching mechanism from direct magnetic field switching (high energy) to electric field-induced magnetoelectric coupling switching (low energy). By applying voltage to the magnetoelectric capacitor, the magnetization orientation is switched through the magnetoelectric effect, dramatically reducing the switching energy requirement while maintaining ease of operation.

Inventive Principle:

Principle #35Parameter changes

3Power

If MTJ readout mechanism is used, then output signal strength increases, but device complexity increases

Engineering Contradiction:

Improveoutput signal strengthVSAvoidstructure complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The device is segmented into two functional modules: a magnetoelectric switching capacitor for low-power state switching and a pair of magnetic tunnel junctions for signal readout. This segmentation allows each component to be optimized for its specific function while working together to achieve both strong output signals and manageable device complexity.

Inventive Principle:

Principle #1Segmentation

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 MEMTJ device offers non-volatile logic states with a bipolar output voltage capable of switching the logic state of subsequent devices, enabling cascading logic operations and maintaining state retention even after power is removed.

Implementation Method 1

Application of a potential difference across the magnetoelectric capacitor can cause the magnetization orientation of the ferromagnetic layer to switch if the magnitude of the potential difference is large enough

Methodology Applied

Scientific EffectMagnetoelectric effect:

Implementation Method 2

Magnetic tunnel junctions are devices in which electrons can tunnel through a thin insulating layer positioned between two ferromagnets with the amount of current at a given voltage that can flow between the ferromagnets depending on the relative orientation of magnetization between the two ferromagnets

Methodology Applied

Scientific EffectTunnel magnetoresistance: Magnetoresistance

Data Source

PatentUS12615967B2Magnetoelectric logic with magnetic tunnel junctions

Publication Date: 2026.04.28 INTEL CORP

AI summary

Magnetoelectric magnetic tunnel junction (MEMTJ) logic devices comprise a magnetoelectric switching capacitor coupled to a pair of magnetic tunnel junctions (MTJs) by a conductive layer. The logic state of the MEMTJ is represented by the magnetization orientation of the ferromagnetic layer of the magnetoelectric capacitor, which can be switched through the application of an appropriate input voltage to the MEMTJ. The magnetization orientation of the magnetoelectric capacitor ferromagnetic layer is read out by the MTJs. The conductive layer is positioned between the capacitor and the MTJs. The MTJ ferromagnetic free layers are exchange coupled to the ferromagnetic layer of the magnetoelectric capacitor. The potential of an MTJ free layer is based on a supply voltage applied to the reference layer of the MTJ. The MTJ reference layers have a magnetization orientation that is parallel or antiparallel to the magnetization orientations of the ferromagnetic layer of the magnetoelectric capacitor.