Ferromagnetic Spin Current Detection via Inverse Spin-Hall Effect

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current spintronic devices that generate and detect pure spin current are costly due to reliance on non-magnetic metals with strong spin-orbit coupling, such as Pt and Au, which have high material costs and limited efficiency in spin and charge conversion.

Innovation Solution

The use of ferromagnetic metals, such as permalloy, in combination with a magnetic dielectric layer, to demonstrate the inverse spin-Hall effect for generating and detecting pure spin currents, offering higher efficiency and lower material costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If non-magnetic metals with strong spin-orbit coupling (Pt, Au) are used for pure spin current generation and detection, then spin current detection capability is achieved, but material cost increases significantly

Engineering Contradiction:

Improvespin current detection capabilityVSAvoidmaterial cost

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent replaces expensive non-magnetic metals (Pt, Au) with inexpensive ferromagnetic metals that can perform the same spin current detection function through the inverse spin Hall effect, significantly reducing material cost while maintaining detection capability

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameter from non-magnetic metals with strong spin-orbit coupling to ferromagnetic metals with appropriate magnetic properties, enabling the same functional effect (inverse spin Hall effect) but with much lower cost materials

Inventive Principle:

Principle #35Parameter changes

2Power

If non-magnetic metals with strong spin-orbit coupling are used for pure spin current generation, then pure spin current can be generated, but spin and charge conversion efficiency is limited

Engineering Contradiction:

Improvespin and charge conversion efficiencyVSAvoidmaterial cost

Core Design Contradiction:

PowerVSQuantity of substance

Solution Approach 1:

The patent substitutes costly non-magnetic metals with cheap ferromagnetic metals, achieving the same spin current generation function through different physical mechanisms (spin pumping, spin Seebeck effect) while reducing material expense

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent employs composite structures combining ferromagnetic metals with magnetic dielectric layers or heavy metal layers, creating multifunctional materials that achieve both efficient spin current generation and detection while maintaining cost effectiveness

Inventive Principle:

Principle #40Composite materials

3Use of energy by moving object

If ferromagnetic metals are used as pure spin current detectors, then energy consumption during writing and reading is reduced, but device structure complexity increases

Engineering Contradiction:

Improveenergy consumptionVSAvoiddevice structure

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent creates composite structures with ferromagnetic metal layers combined with magnetic dielectric layers or heavy metal layers, where the combination enables low-energy operation through enhanced spin-charge conversion while the layered structure provides the necessary functional complexity

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The ferromagnetic metal layer serves multiple functions simultaneously: it acts as both the spin current detector and the magnetic storage medium, while also enabling low-energy writing through spin transfer torque, thereby reducing overall device complexity despite the composite structure

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Ferromagnetic metals enable superior pure spin current detection with lower energy consumption and reduced material costs, enhancing the efficiency of spin and charge conversion in spintronic devices.

Implementation Method 1

The most widely used method for detecting a pure spin current is the inverse spin-Hall effect (ISHE) that converts spin current back into a charge current

Methodology Applied

Scientific EffectInverse spin-Hall effect: Hall Effect

Implementation Method 2

spin Hall effect (SHE), lateral spin valve, spin pumping, and spin Seebeck effect (SSE), by exploiting heavy (high-Z) metals with strong spin-orbit coupling (SOC) for the generation or detection of the pure spin current

Methodology Applied

Scientific EffectSpin Hall effect: Hall Effect

Implementation Method 3

a magnetic dielectric layer, to demonstrate the inverse spin-Hall effect for generating and detecting pure spin currents

Methodology Applied

Scientific EffectMagnetism: Magnetism

Data Source

PatentUS9128142B1Ferromagnets as pure spin current generators and detectors

Publication Date: 2015.09.08 JOHNS HOPKINS UNIVERSITY

AI summary

Provided is a spintronics device. The spintronics can include a ferromagnetic metal layer, a positive electrode disposed on a first surface portion of the ferromagnetic metal layer, and a negative electrode disposed on a second surface portion of the ferromagnetic metal.