Spintronics Memory Structure Using Carrier Mobility Gradients
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Solution Overview
Problem
Current spin current generation theories rely on spin orbit interaction (SOI) specific to certain materials like platinum, limiting the intensity of spin current and material options for spintronics devices and magnetic memories.
Innovation Solution
A spintronics device with a region having a gradient of carrier mobility or electrical conductivity generates spin current through the rotation of electron velocity fields, eliminating the need for specific materials by converting angular momentum into spin current without relying on SOI, using materials like copper, aluminum, or silicon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If spin current generation relies on spin orbit interaction (SOI) in specific materials like platinum, then spin current can be generated, but the spin current intensity is limited and material options are restricted
Solution Approach 1:
The invention changes the fundamental parameter for spin current generation from relying on material-specific spin orbit interaction to utilizing carrier mobility gradients. By controlling the gradient of carrier mobility through compositional gradients or structural designs in alloy systems, the patent achieves spin current generation that is not limited by material-specific SOI effects, thereby increasing both spin current intensity and material selection flexibility
Solution Approach 2:
The invention creates a universal spin current generation mechanism that works across multiple material systems (alloys, semiconductors, conductors) by utilizing the common phenomenon of carrier mobility gradients. This universal approach based on the diffusion current equation and carrier mobility differences eliminates the need for specific materials with strong SOI, allowing wide material adaptability while maintaining high spin current intensity
2Loss of energy
If conventional spin current generation methods are used, then spin current can be produced, but energy consumption is high due to Joule heat generation
Solution Approach 1:
The invention replaces the conventional electrical current-based spin generation mechanism with a diffusion-driven mechanism. By utilizing the natural diffusion of carriers from high mobility to low mobility regions, the system generates spin current without requiring high current densities, thereby reducing Joule heating and energy consumption while improving spin current efficiency
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 enables the generation of a large spin current comparable to or exceeding that based on SOI, using a wide range of materials regardless of their magnetic properties or SOI presence, reducing energy consumption and enhancing device performance.
Implementation Method 1
A spin current is generated by rotation of a velocity field of an electron caused by the gradient
Implementation Method 2
A magnitude of rotation of this velocity field can also be regarded as vorticity. Due to the rotation of this velocity field, 'angular momentum' is present in a flow of a plurality of electrons in the region. This angular momentum is converted into a spin (upspin or downspin) in one direction.
Implementation Method 3
when one electron is focused on, the electron repeatedly accelerates and decelerates while colliding with a scatterer in the material, and travels in a voltage application direction in the material while moving in a zigzag manner
Implementation Method 4
a distribution in which the moving velocities of the electrons are not uniform occurs in the region having the gradient of the carrier mobility or electrical conductivity. At this time, focusing on a minute region in the region, it can be considered that a velocity field (vector field) of the electron is rotating in the minute region due to a difference between the moving velocities of the electrons
Data Source
AI summary
Provided are a spintronics device, a magnetic memory, and an electronics device capable of generating a large spin current without depending on a specific material. A spintronics device includes a first conductive layer, a second conductive layer having carrier mobility or electrical conductivity lower than that of the first conductive layer, and a boundary region between the conductive layers. The boundary region has a gradient of carrier mobility or electrical conductivity, and a spin current is generated by rotation of a velocity field of an electron caused by the gradient.