Current-Controlled Hall Memory for Tunable AHE Polarity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices fail to effectively change the polarity and magnitude of the anomalous Hall effect (AHE) signal in response to variations in input current and magnetization direction, limiting their functionality and applications.
Innovation Solution
A semiconductor device comprising a free magnetization layer with a ferromagnetic and nonmagnetic metal layer, where the Hall voltage is generated by an AHE, and controlled input currents result in local minimum and maximum values, allowing simultaneous changes in polarity and magnitude of the AHE signal based on input current and magnetization direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional Hall effect devices are used, then a Hall voltage is generated by an external magnetic field, but the device cannot simultaneously change the polarity and magnitude of the AHE signal according to input current and magnetization direction
Solution Approach 1:
The patent changes the control parameter from external magnetic field to input current. By varying the input current magnitude and direction, the device can simultaneously control both the polarity and magnitude of the AHE signal. This is achieved through the current-controlled magnetization switching mechanism in the ferrimagnetic film, where different current levels produce different magnetization states and corresponding AHE signals.
Solution Approach 2:
The patent employs a composite ferrimagnetic film structure consisting of multiple magnetic sub-layers with opposite magnetization directions. This composite structure enables the material to exhibit controllable AHE characteristics where the net magnetization can be switched between different states by applying appropriate current, thereby achieving simultaneous control of polarity and magnitude of the AHE signal.
2Measurement precision
If the input current value changes, then the Hall voltage magnitude changes, but the polarity cannot be controlled simultaneously
Solution Approach 1:
The patent utilizes parameter changes in the input current (magnitude and direction) to simultaneously control both the polarity and magnitude of the AHE signal. By adjusting the input current to specific threshold values, the magnetization direction switches, which in turn changes the polarity of the Hall voltage. The continuous variation of current magnitude allows precise control of the signal strength.
3Quantity of substance
If external magnetic field is applied to generate Hall voltage, then the Hall effect can be observed, but the device cannot function as multi-bit memory storage
Solution Approach 1:
The patent replaces the external magnetic field mechanism with a current-controlled magnetization switching mechanism. Instead of using external magnetic fields to write data (which consumes energy and provides limited states), the device uses spin-polarized current to directly switch the magnetization direction of the ferrimagnetic film. This enables multiple stable magnetization states that can represent multiple bits of data, increasing storage capacity while reducing energy consumption compared to external field methods.
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 enables precise control over the AHE signal, enabling it to function as a memory device storing multiple bits of data and enhancing its operational flexibility and efficiency.
Implementation Method 1
a Hall voltage is generated by an AHE occurring in the ferromagnetic layer of the free magnetization layer due to an input current flowing in the nonmagnetic metal layer
Data Source
AI summary
A semiconductor device includes a free magnetization layer including a ferromagnetic layer and a nonmagnetic metal layer including current electrodes receiving an input current and Hall voltage electrodes outputting a Hall voltage. The Hall voltage is generated by an anomalous Hall effect occurring in the ferromagnetic layer of the free magnetization layer due to the input current flowing in the nonmagnetic metal layer. The Hall voltage has one of a local minimum value and a local maximum value when a value of the input current sequentially changes from a first value to a second value. One of the first value and the second value is greater than the other one of the first value and the second value.