Spin Rectifying Device Using Rashba Spin Orbit Interaction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In the field of spin electronics, there is a demand for rectifying devices that can achieve high spin polarization rates for electrons flowing in one direction while preventing electron flow in the opposite direction.

Innovation Solution

A spin-rectifying device with a one-dimensional channel having a zinc blende crystal structure, formed on a (001)- or (110)-plane, and equipped with side gates to create a depletion layer, utilizes external and effective magnetic fields generated by a Rashba spin orbit interaction to achieve high spin polarization and directional electron flow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional spin transistor using gate electrode and spin orbit coupling is used, then spin control is achieved, but the spin polarization rate is insufficient for high-performance rectification

Engineering Contradiction:

Improvespin polarization rateVSAvoidrectification performance

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent employs asymmetric quantum point contact confinement potential to generate strong spin-orbit coupling. The highly asymmetric confining potential at the point contact creates significant spin-orbit interaction, which eliminates the need for gate electrodes and achieves high spin polarization rates necessary for reliable spin rectification

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent replaces the conventional gate electrode control mechanism with a quantum point contact structure that utilizes intrinsic spin-orbit coupling. This substitution eliminates the need for external gate electrodes while achieving superior spin polarization through the asymmetric quantum confinement potential

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If electrons are allowed to flow bidirectionally, then device operation flexibility is maintained, but spin rectification cannot be achieved

Engineering Contradiction:

Improvespin rectification capabilityVSAvoidelectron flow direction control

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic control of electron flow direction by applying external magnetic fields to manipulate spin-polarized electron transport. The device transitions from static bidirectional conduction to dynamic unidirectional spin rectification through magnetic field control, enabling spin diode functionality while maintaining operational flexibility

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If ferromagnetic materials are used for spin injection, then high spin polarization is achieved, but device complexity and material requirements increase

Engineering Contradiction:

Improvespin polarization rateVSAvoidmaterial structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the ferromagnetic material component from the spin injection mechanism. By utilizing intrinsic spin-orbit coupling in the quantum point contact structure, the device achieves high spin polarization without requiring ferromagnetic materials, thereby simplifying the material structure and device fabrication

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The quantum point contact structure generates its own spin-orbit coupling through the asymmetric quantum confinement potential, eliminating the need for external ferromagnetic materials. The structure serves itself by utilizing its inherent geometric asymmetry to produce the necessary spin polarization for rectification

Inventive Principle:

Principle #25Self-service

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 effectively polarizes electrons to a high degree in one direction while preventing flow in the opposite direction, enhancing spin rectification and enabling applications in quantum computing and semiconductor devices without the need for ferromagnetic materials.

Implementation Method 1

utilizes external and effective magnetic fields generated by a Rashba spin orbit interaction to achieve high spin polarization and directional electron flow control

Methodology Applied

Scientific EffectRashba spin orbit interaction:

Implementation Method 2

The external magnetic field generating unit may generate the external magnetic field in the direction of the effective magnetic field or in the opposite direction from the direction of the effective magnetic field

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP2736080B1Spin rectifying device, spin transistor, and spin rectifying method

Publication Date: 2017.02.01 THE JAPAN SCI & TECH AGENCY

AI summary

A rectifying device includes: a one-dimensional channel (18) formed with a semiconductor, electrons traveling through the one-dimensional channel; an electrode (26) that applies an effective magnetic field generated from a spin orbit interaction to the electrons traveling through the one-dimensional channel by applying an electric field to the one-dimensional channel, the effective magnetic field being in a direction intersectional to the direction in which the electrons are traveling; and an external magnetic field generating unit (38) that generates an external magnetic field in the one-dimensional channel.