Quantum Variational Network Classifier for Kernel Optimization

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Solution Overview

Problem

Quantum support vector machines face challenges in controlling kernel functions for quantum circuits, leading to overfitting and difficulty in generating proper decision boundaries, especially when dealing with various types of data and datasets.

Innovation Solution

A method involving quantum hardware and processors that transform qubit states using rotation angles to compute inner products, minimize an objective function, and build a kernel matrix, facilitating maximal separation of data classes and improved classification accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If kernel functions are used in quantum support vector machine, then classification accuracy is improved, but overfitting occurs and decision boundary control becomes difficult

Engineering Contradiction:
Improveclassification accuracyVSAvoidoverfitting control
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent transforms the kernel function approach into a parameterized quantum circuit approach where the decision boundary is controlled by explicit circuit parameters (rotation angles, evolution times) rather than implicit kernel functions. This allows direct optimization of parameters to achieve both high accuracy and good generalization by minimizing an objective function that balances classification performance and model complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional mechanical kernel computation system with a quantum circuit system that uses unitary transformations and parameterized gates. This substitution enables more flexible and controllable decision boundary formation through quantum interference and entanglement effects, while the parameters can be systematically optimized to prevent overfitting.

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

2Measurement precision

If kernel functions are used in quantum support vector machine, then model performance is improved, but device complexity increases

Engineering Contradiction:
Improvemodel accuracyVSAvoidkernel function complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex kernel function computation into multiple simpler quantum circuit operations including feature map preparation, parameterized unitary transformations, and measurement. This segmentation allows each component to be implemented using basic quantum gates and operations, reducing the overall device complexity while maintaining the ability to achieve high model accuracy through coordinated parameter optimization.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If quantum circuits transform qubit states with rotation angles, then data separation is maximized, but computational resources increase

Engineering Contradiction:
Improvedata class separationVSAvoidcomputational resources
Core Design Contradiction:
Manufacturing precisionVSPower

Solution Approach 1:

The patent uses dynamic parameter optimization where rotation angles and circuit parameters are adjusted iteratively based on the objective function evaluation. This dynamic approach allows the system to achieve maximal data separation with optimized computational resources by avoiding fixed over-engineered circuits and instead adapting the circuit parameters to the specific characteristics of the input data.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS20240070508A1Quantum variational network classifier
Publication Date: 2024.02.29 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US20240070508A1 patent drawing
  • US20240070508A1 patent drawing
  • US20240070508A1 patent drawing

AI summary

A processor can control quantum hardware to transform qubit states associated with a plurality of pairs of data points in a training dataset using a circuit parameter representing a rotation angle. Inner products of transformed qubit states associated with the plurality of pairs of data points can be computed. The processor can minimize an objective function based on the inner products, where the minimizing finds a target circuit parameter representing a target rotation angle that minimizes the objective function. A processor can build a kernel matrix based on the inner products computed for a sample dataset and the target circuit parameter passed to the quantum hardware. A classification algorithm can use the kernel matrix to classify the sample dataset.