Magnonic Matrix-Vector-Multiplier Spin Wave Phase Control

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Solution Overview

Problem

Existing matrix-vector multiplier (MVM) devices, particularly those using electrooptic effects, face limitations in trainability and bidirectionality, which restrict the efficient implementation of backpropagation algorithms in neural networks due to small electrooptic effects and the need for separate components for wave generation and detection.

Innovation Solution

A stacked layer structure with a waveguide element and transducer arrangement that generates and detects spin waves, utilizing a control mechanism with a direct current electric source to modify the phase velocity of spin waves, enabling bidirectional operation and efficient backpropagation algorithms through magnetoelectric effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If electrooptic effects are used for wave generation and detection in MVM, then the device can perform matrix-vector multiplication, but the trainability is limited due to small electrooptic effects

Engineering Contradiction:
ImprovetrainabilityVSAvoidsmall electrooptic effects
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces electrooptic effects with magnetoelectric effects for controlling wave propagation. By using magnetic fields instead of electric fields to modulate the waveguide medium, the system achieves a much larger tuning range and enhanced trainability for neural network applications.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from electric field (electrooptic) to magnetic field (magnetoelectric). This parameter change enables a significantly larger modulation depth and tuning range, directly addressing the limitation of small electrooptic effects and improving trainability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If separate components are used for wave generation and detection, then the MVM can operate, but bidirectionality is limited

Engineering Contradiction:
ImprovebidirectionalityVSAvoidseparate components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements bidirectional operation by making the waveguide element functional in both directions. The same waveguide structure can guide spin waves from left to right and from right to left, enabling convenient implementation of backpropagation algorithms without requiring separate components for forward and backward propagation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the wave generation and detection functions into a unified bidirectional waveguide system. By using the same magnetoelectric waveguide for both forward propagation (input to hidden layer) and backward propagation (error signal from output to hidden layer), the system achieves bidirectionality while reducing component complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If conventional CMOS transistors are used for linear transformations, then the device can perform matrix operations, but the operations are costly to realize

Engineering Contradiction:
Improvecomputation efficiencyVSAvoidcostly operations
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent replaces conventional CMOS transistor-based linear transformations with a physics-based wave interference system. By using spin wave interference patterns in a magnetoelectric waveguide, the system performs matrix-vector multiplication in an analog fashion, achieving higher computational efficiency and lower energy consumption compared to digital CMOS implementations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution provides a more efficient and convenient implementation of backpropagation algorithms, enhancing the trainability and bidirectionality of MVMs, allowing for effective training of neural networks with a larger tuning range and compact, cost-effective design.

Implementation Method 1

utilizing a control mechanism with a direct current electric source to modify the phase velocity of spin waves, enabling bidirectional operation and efficient backpropagation algorithms through magnetoelectric effects

Methodology Applied
Scientific EffectMagnetoelectric effect: Magnetoelastic Effects

Implementation Method 2

the waveguide element is configured to confine and to provide interference of the spin wave(s) propagating therein

Methodology Applied
Scientific EffectSpin wave propagation: Waveguide

Implementation Method 3

Via the control element(s), the control mechanism is configured to modify the phase velocity of the spin wave(s) propagating in the waveguide element

Methodology Applied
Scientific EffectPhase velocity modulation: Magnetoelastic Effects

Data Source

PatentEP3632840B1Arrangement for use in a magnonic matrix-vector-multiplier
Publication Date: 2023.06.28 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP3632840B1 patent drawingFigure 1a~1b
  • EP3632840B1 patent drawingFigure 2
  • EP3632840B1 patent drawingFigure 3

AI summary

An arrangement (100) for use in a matrix-vector-multiplier, comprising a stack of material layers (110) arranged on a substrate (120), and a waveguide element (200) formed in at least one material layer in the stack. The arrangement further comprises a transducer arrangement (300) which is coupled to the waveguide element. The transducer arrangement is configured to generate and detect spin wave(s) in the waveguide element, and wherein the waveguide element is configured to confine and to provide interference of the at spin wave(s) propagating therein. The arrangement further comprises a control mechanism (400) comprising at least one control element (500) coupled to the waveguide element, and a direct current electric source (600) coupled to the at least one control element. The control mechanism, via the at least one control element, is configured to modify the phase velocity of the spin wave(s) propagating in the waveguide element.