Antiferromagnet Field-Effect Logic Circuits with Spin Orbital Coupling

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Solution Overview

Problem

Conventional magnetic devices based on ferromagnets suffer from large switching delays, leading to increased power and energy dissipation, which hinders their ability to sustain exponential chip throughput and compete with CMOS technology.

Innovation Solution

The development of antiferromagnet field-effect transistor (AFMFET) logic circuits utilizing spin orbital coupling channels with opposing preferred current paths, where an antiferromagnetic material generates boundary magnetization to create low- and high-resistance current paths, enabling efficient voltage-controlled logic operations without the need for dedicated MOSFETs or special clocking schemes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If ferromagnet-based magnetic devices are used, then non-volatility and low-voltage operation are achieved, but switching delay increases to nanoseconds leading to increased power and energy dissipation

Engineering Contradiction:

Improveenergy dissipationVSAvoidswitching delay

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent changes the fundamental magnetic ordering parameter from ferromagnetic to antiferromagnetic state, which fundamentally alters the switching dynamics. Antiferromagnetic materials exhibit much faster switching speeds (picosecond range) compared to ferromagnetic materials (nanosecond range) due to their shorter spin precession periods and absence of macroscopic magnetization, thereby resolving the contradiction between energy efficiency and switching speed

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures including antiferromagnetic materials combined with spin orbital coupling materials (such as topological insulators or heavy metals). This composite approach leverages the fast switching of antiferromagnets and the strong spin-orbit coupling effects to achieve both low energy dissipation and ultrafast switching, simultaneously addressing both parameters of the contradiction

Inventive Principle:

Principle #40Composite materials

2Speed

If conventional charge-based FETs are used, then fast switching speeds are achieved, but power and energy dissipation increase compared to magnetic devices

Engineering Contradiction:

Improveswitching speedVSAvoidpower dissipation

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent substitutes charge-based control mechanisms with spin-based control mechanisms. Instead of relying on charge accumulation and transport as in conventional FETs, the invention uses spin orbital coupling effects in antiferromagnetic materials to control resistance states, enabling fast switching with significantly reduced power dissipation by exploiting spin-dependent scattering rather than charge motion

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from charge-based operation to spin-based operation by changing the fundamental control parameter. Antiferromagnetic field-effect devices utilize spin polarization and spin-orbit coupling to modulate resistance, achieving both high-speed switching (inheriting from fast antiferromagnetic dynamics) and low power consumption (by avoiding continuous charge flow required in conventional FETs)

Inventive Principle:

Principle #35Parameter changes

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 achieves competitive switching speeds with low energy dissipation, allowing for compact and efficient logic implementation comparable to CMOS technology, while reducing power consumption and footprint area, and enabling the construction of logical devices like inverters, NAND gates, and majority gates.

Implementation Method 1

an AFM material that extends in a first direction and an input voltage terminal that extends opposite the AFM material... configured to provide a boundary magnetization thereof

Methodology Applied

Scientific EffectField effect: Electric Field

Implementation Method 2

first and second spin orbital coupling channels can be on the AFM material, where the first and second spin orbital coupling channels are configured to form a low-resistance current path in the first channel and a high-resistance current path in the second channel, respectively, responsive to a spin orbital coupling effect generated by the boundary magnetization

Methodology Applied

Scientific EffectSpin orbital coupling:

Data Source

PatentUS11043592B2Antiferromagnet field-effect based logic circuits including spin orbital coupling channels with opposing preferred current paths and related structures

Publication Date: 2021.06.22 GEORGIA TECH RES CORP

AI summary

An anti-ferromagnetic (AFM) voltage-controlled field effect logic device structure can include an AFM material that extends in a first direction and an input voltage terminal that extends opposite the AFM material. An oxide material can be located between the AFM material and the input voltage terminal. A first spin orbital coupling (SOC) material can extend in a second direction across the AFM material to provide a first SOC channel with a drain voltage terminal at a first end of the first SOC channel and an output voltage terminal at a second end of the first SOC channel that is opposite the first end. A contact can be electrically coupled to the output voltage terminal and configured to electrically couple to a second SOC material extending in the second direction spaced apart from the first SOC material to provide a second SOC channel.